OMC's 4-Rotor Wankel Racing Engine - The Real Story

[Big Steve 435]

I`m a big fan of the sprint jet series but have not seen this boat. I would love to tho.

DB

Here ya go!


http://www.youtube.com/watch?v=mXWCzGnQQeg


And
<iframe width="640" height="360" src="//www.youtube.com/embed/TBJPgG6FRbA?feature=player_embedded" frameborder="0" allowfullscreen=""></iframe>

[Big Steve 435]

http://www.rotaryeng.net/rb3rot2.jpg

This little monster makes 1200 hp

[knot<safe77]

I definitely agree with getting more reliable power from a rotary. Hands down . And the13g was a three rotar that was used in the 84 lamans it was used in the 727. 4 rotor was later used in the late 80s dominating the competition. But they did use a three rotor almost identical everything except obviously the eccentric shaft. And the outside of the housings were smaller.. they also made 10a 12a 13a 13b 13g. There were So many but if u talk to an aussie or a puerto rican who knows there stuff most affordable fast street rotaries. Are 13b four port cosmo engines with a full bridge port turbo and rx8 renesis light weight rotars that seems to be the kick ass package.. my cousin and i have been running one for 6 years in a 1970 mazda r100. Puts down 480 hp and runs 10,80 s all day...

[Big Steve 435]

Nice result! Knot !

I would like to know more about your cousins motor combo

Any details of boost #s or turbo , RPM

Companies you worked with

Thanks

Big Steve

[Big Steve 435]

one more for the Da Bull

http://www.youtube.com/watch?v=bpxK2ub-qCs

[knot<safe77]

I'm sorry I was a little off t66 turbo low compression turbo 2 rotors re block 4 port 480 hp at 8000 rpm..

[Rotary John]

OK guys enough. This is my thread about the OMC rotary race engine, not modified Mazda's. I enjoy seeing your stuff, but start your own thread. Thanks

[Big Steve 435]

OK guys enough. This is my thread about the OMC rotary race engine, not modified Mazda's. I enjoy seeing your stuff, but start your own thread. Thanks

Sorry, I never intended to Jack your thread,

I have gone to see what happened to the OMC motor at Moller in Davis,ca

I only wish I could get a rotary powered outboard !

The only thing left is making one myself out of whats been made

You guys were on the right track decades ago

Thank you for your posts !

If you have any ideas on putting a Rotary O/B together

I would like to here them

I read the complete thread on Boat racing facts, a while back "09

And have been motivated by it. To research everything Rotary

You lit A fire that just won't go out !

Thank you again

Big Steve

[powerabout]

Somebody in oz has the rotary to merc adapter plate
So thats part of tne job done

[Mark75H]

Even OMC could not fight the EPA sunshine. They (EPA) had way to much power, (Nothings changed). If the EPA got wind of how good the Rotary was in emissions (10 times better than 2 stroke outboards in 1976) & their ultra low fuel consumption then they would have banned the 2 stroke outboard instantaniously, just like they banned the 2 stroke motorbike instantaniously. Problem is it would have taken years & huge amount of money for OMC to retool a rotary range. And all other brands of 2 stroke Outboard Motors would have been history as well.

I have always doubted this claim, so I asked Charlie Strang. Here is his response:


Dear Sam:
I'm afraid the story about the reputed cleanliness if the rotary is a figment of someone's over active imagination! The primary problem with the engine was its extreme dirtiness. The long, flat combustion chamber created by the rotor in its somewhat triangular housing resulted in a "wet chamber" that could be cleaned up to meet coming pollution standards only by adding a very expensive catalytic converter to the exhaust system.

Aside from being dirty, the engine was expensive to manufacture because of the tool steel seals it required for any kind of life and the very expensive alloy coating needed in the trichinosis housing to withstand the wear created by the seals.

When all was said and done it was far less costly to build a direct-injected two-cycle piston engine or even a four-cycle engine to meet the emerging clean exhaust laws.

As far as I know, OMC was the only company in the USA or North America ever to put a rotary into actual production. We built several thousand single-rotor engines and sold them in snowmobiles just before the onset of new exhaust laws finished the day of the Wankel. All in all. the engine was fun to work with --including our four-rotor racing engines -- but in the end it amounted to one big and expensive waste of time!!

Regards, Chas S.

PS: In answer to one of your questions which I overlooked, yes-we constantly analyzed the rotary engine emissions, always seeking to improve them --without success.

[Speedfab]

Mr Strang meant to say trochoidal, not trichinosis (a parasitic infection), in reference to rotor housing shape. Rotaries are not only very "dirty" emissions wise due to the inefficient long convex rectangle shape of the rotor face that contains the combustion chamber, they also have extremely high EGTs due to the fact that the exhaust port is never closed... there is always a rotor face on "exhaust stroke". As noted above, the seals are also a tripping point due to friction, wear, and the fact that if they are hard enough to survive they are brittle enough to be fractured by detonation, which is a constant problem. It's easy to seal a round bore piston and use cylinder pressure to force the seal to do its job, Rotaries have to use springs behind the seals - apex, side, and corner, and they lose effectiveness with heat and wear. The "you can turn one 10 grand all day" deal is another wives tale - revs kill rotaries even faster than their piston counterparts - I'll bet on a Honda F20 vs a Renesis turning 9K all day long with regard to durability. The last RX7s were redlined at 7 grand, and for good reason. Yes racing engines can get away with it for brief periods, but rotor bearings, housings, and especially end housings get the hell beat out of them by high RPMs because of eccentric shaft flex.

Bottom line... They are fun to play with and can make impressive power for their size, but efficiency and durability shouldn't be used in the same sentence with rotary.

Rotor fans, please dont take any of this the wrong way, I like them. They are part of how I make a living. Just wanted to clear up some BS misconceptions. I also don't want to crap up Rotary John's thread - I think the OMC rotaries were a phenomenal piece of engineering, especially at that time, and applaud those guys for the effort.

[powerabout]

The enginee has a bad surface to volume ratio so bad nox
This was explained to us omc service schools and of course we had the mazda in oz and the 70' saw the start of emission regs in cars so we knew
Direct injection might give it another life

[Mark75H]

The enginee has a bad surface to volume ratio so bad nox
This was explained to us omc service schools and of course we had the mazda in oz and the 70' saw the start of emission regs in cars so we knew
Direct injection might give it another life Doesn't that give new rotor seal lube problems?

[powerabout]

Doesn't that give new rotor seal lube problems?
I have never studied a rotary so I dont know all the issues but for sure there are plenty in my old home town that know
Maybe we will see an E-tec Rotary??
An E-tec crossflow would be a great work horse

FYI
http://www.riceracing.com.au/apex-seals.htm

[jackiewilson]

Now----if I was a BASTY nastard (which I am not) I would be chortling and rolling all over the hog market after reading C/S's insight into the ROTORY project.
Out of the mouths of babes and presidents etc.etc.etc.
Not only is it a mucky motor, it's totally non-viable, never has been, never will be, not cost effective, not economical, Jesus H, C expensive and a heartbreaker to dedicated engineers.
After more than a hundred years, you would think that the penny would drop, the damn thing is fatally flawed, I know that Hope reigns eternal and all that but the design needs binning.

[powerabout]

Jackie
Think you need to do a phd on the rotary
All that research will give you something to do
For your proposal you could do either why they work or why they dont work
Same job as you will still need the same evidence
Cheers

[T2x]

So a fresh, low RPM rotary is a decent, if dirty, motor? Ours was traded in with low mileage...but man it was a rocketship while we had it... Kind of a shame really..given the simplicity of the design.

[Rotary John]

Its amazing to me all the engineering experts on this subject that are so full of crap, including Strang. Rotaries are low on NOx due to lower combustion temps and high on HC due to surface to volume ratios (quench surfaces) as compared to 4-strokes. Exhaust temps are high due to more complete combustion and are similar to a 4-stroke. The heat generated in the exhaust system is indeed more for a rotary as it is continually exhausting. A 4-stroke only exhausts for approx. 90 degrees of crank rotation and then gets to wait for another complete crank revolution before it happens again. A 2-stroke has lower exhaust temp due to poorer and less complete combustion and the dilution caused by over scavenging. Strang must have been too busy running OMC into the ground to look at the emission testing results we were doing in the early '70's. As compared to a cross scavenged 2-stroke, untreated, the rotary had 10 times less HC. When treated with a thermal reactor with added air, that figure dropped to 100 times less. He was also apparently unaware we had sintered metal apex seal for about a nickel apiece. He spent money on production machinery from Gleason Works for side seal machining and trochoid grinders; just to have fun? There were no emission requirements for outboards or snowmobiles in the early /middle '70's. The first non-automotive emission requirement in the US was Calf. (not Federal) in 1974 that banned 2-stroke motor cycles. California has tested the water cooled version of the 530cc OMC engine from Moller that meets the ultra-low emission certification without any after treatment on pump gasoline. Charlie's memory is his justification pursuing 2-strokes, as oppose to developing emission technology for the forthcoming emission laws regardless if it was direct injected 2-strokes, 4-strokes or rotaries. He didn't and was forced into the disaster that bankrupted OMC. The 4-rotor race engine served his purpose; "Beat Mercury"; which it did very nicely. Once he had the 150ci V-6 to compete with Merc's 122ci engine and didn't need the rotary anymore. Witness the fact that all the Marine Engineering Rotary people; san 1; left the company, including the manager, and all rotary engine development was stopped by 1976. Prior to ANY outboard emission laws. Oh, by the way the Graupner rotary is rated at 18,00/22,000 RPM.

[knot<safe77]

SpEED FAB.... you are very knowledgeable and speak like a true gentlemen i wish everyone could converse like you...but for the emissions on a race engine?? lol. All these stories, fails and bad a pex seals are from the70s. They didn't even invent the cassette player yet... lol Anytime the rotary has raced against piston engines it's kicked butt.. and all the people who don't like them say they blow up or drink fuel... so do mercs i mean that's crazy it's performance we are looking for not a prius right??? And what i just wrote wasn't directed at u . Please don't think I'm pointing fingers u have very good points. Ps renesis motor is junk i know lol..

[Speedfab]

Hi Knot, and thanks. I only mentioned emissions because the post above mine did... And like Rotary John said, their only real emission problem is from hydrocarbons, as a result of incomplete burn in that long rectangular "combustion chamber"... In comparing one to a TWO STROKE, and especially a pre-DI one running on premix, that's a totally moot point. This long chamber with corners and poor quench is part of the reason the Mazdas have leading and trailing sparkplugs for each rotor. They are actually somewhat better than most other engines with regard to oxides of nitrogen... they have an inherent form of inbuilt EGR as the chamber on each rotor face naturally carries some exhaust back around with it after the apex seal closes the exhaust port, and the combustion temps are lower. Apex seal problems predate the 70s, exist right now, and will continue until someone finds some magic unobtanium and pixie dust from which to make them. These engines ARE fragile in comparison to piston engines, make no mistake, and running them rich enough to be safe is part of the fuel consumption issue. They have a very low tolerance for tuning issues, lean mixtures, and excessive spark timing... You can rattle some piston engines all day on bad gas, but you damn sure can't do it to a rotary.

I'll take Rotary John's real life knowledge of these things over internet armchair quarterbacks and rotary fanboys all day. I may have many years of experience with them, I may be an engineer, but he actually ENGINEERED one. Big difference. I'm not just blowing smoke, I think everyone reading this needs to realize how fortunate we are that he is actually here telling us about it. I find the whole thing fascinating.

[Speedfab]

Oh, by the way the Graupner rotary is rated at 18,00/22,000 RPM.

Now John, if you're going to go quoting model/toy engine rev figures, you may as well tell them that a Cox .049 Killer Bee piston engine would turn 28K straight out of the box. Those OS/Graupner wankels were horrible turds when they came out, btw... I bought one. Their seal backing springs would turn to silly putty if you even thought about running one hot, and a little fussy to start even with good compression. They might be better made now, and you can still buy them today from hobby retailers. No doubt they are neat.

[Motv18]

Their a toy with wow factor. They can be cleaned up with valves and cats injector and o2. Still no torque hAving mosquito sounding junk though. Although a 400 hp 300 lbs outboard spinning 10k turning a 10x4 pitch on a 10 foot john boAt hitting 22gps is defiantly awesome.

Ok ok I jest their cool efficient Nd have issues like everything else. Face it this emissions stuff is worse on us then anything it ever did to cars. In the 70's. Took us 40 years for a 400 hp Camarillo from the factory again. Yea their were one offs and little makes here and their. That's were we are at. Outboard or boating in general. 454 big blocks making 150 hp in 4 ton cars.

Now ow you want fun yamma or suzi need to slap a 1100 bike motor on their outboard. And let it hit 11-13k rpm

[knot<safe77]

How is it considered such junk when it's done so well in many different performance motor sports? I know it's not a better engine then a piston engine overall. it's apple's to oranges but how such junk?

[powerabout]

4 stroke bike engines dont work as an outboard as they wont pull the skin off a rice pudding
No gears in an outboard

[Rotary John]

Thanks for the support. Everyone please remember, this engine and the information is from 1972/75. Not today. So when I talk about 2-strokes we are talking about cross scavenged OMC and direct charged Mercs. OMC had 1 loop engine at the time and Merc was only in development of their V-6 looper. The only 4-stroke was the Fisher Price/Homelite.
Apex seals are no longer a problem. Several solutions are now available that virtually eliminate any problems. You also have to remember that it is the apex seal-trochoid coating that's makes it work. We hadn't fully solve this problem back in the '70 on the race engine. I had developed alternative seal in snowmobile testing, but never actually put them into the race engine. We never DNF because of apex seals, so I was hesitant to put different seals in a race engine. As far as fuel and timing goes. A rotary is very insensitive to spark timing as far as power is concerned. Remember the rotor (ala combustion) is going 1/3 the crank speed. Timing is important for emissions as seen in Mazda engines. The trailing spark plug can increase power by 8/10% while also effecting emissions. We never used dual plugs on this engine series as our experience had shown housing cracking problems. Besides at the time we really didn't need any more power. The rotary is also very tolerant to fuels. It can run on 85 Octane w/o problems. In fact at Windermere, Merc want Leek to go half's on a load of av. gas but said no as we didn't need it. It again goes back to the relatively slow, stationary flame front in this engine. As told before, for some reason we were never able to figure out, the race engine wanted to run super lean for best power. We measured BSFC of .385 at LBT but would fail rotor bearings if we ran at that level (ala Parker). We would run RBT of about .6. which was still better than the best 2-stroke of the time. I would love to put todays development into that engine and run it on todays generation boat. It ani't gona happen, but I can still dream what if.

[powerabout]

Many thanks John
Hey if that adapter that guy in Melbourne made pops up somewhere I could see I might take on the project but then I again I might make my own for a short OMC mid/V8 lower

[Speedfab]

This is very interesting, I'm glad I got to start the day learning a little. Nearly all of what I know or think I know relates to pushing the limits of turbocharged rotaries and John is talking about an engine running at atmospheric manifold pressure... renders those fuel and timing points moot with regard to the OMC project (and any other normally aspirated rotary) due to chamber pressure differences. I'll stop comparing apples and oranges now. Thank you for your knowledge Mr. Sheldon. I'll have to take a picture of a rotor face pushed in from pressure between the chamber and seal later, you might get a chuckle out of that.

[Rotary John]

This is very interesting, I'm glad I got to start the day learning a little. Nearly all of what I know or think I know relates to pushing the limits of turbocharged rotaries and John is talking about an engine running at atmospheric manifold pressure... renders those fuel and timing points moot with regard to the OMC project (and any other normally aspirated rotary) due to chamber pressure differences. I'll stop comparing apples and oranges now. Thank you for your knowledge Mr. Sheldon. I'll have to take a picture of a rotor face pushed in from pressure between the chamber and seal later, you might get a chuckle out of that.
We turbo charged a snowmobile engine once, Shut it down at 54HP @3000 rpm; overheating.

[Rotary John]

This is very interesting, I'm glad I got to start the day learning a little. Nearly all of what I know or think I know relates to pushing the limits of turbocharged rotaries and John is talking about an engine running at atmospheric manifold pressure... renders those fuel and timing points moot with regard to the OMC project (and any other normally aspirated rotary) due to chamber pressure differences. I'll stop comparing apples and oranges now. Thank you for your knowledge Mr. Sheldon. I'll have to take a picture of a rotor face pushed in from pressure between the chamber and seal later, you might get a chuckle out of that.
We turbo charged a snowmobile engine once, Shut it down at 54HP @3000 rpm; overheating. I can imagine what can be done. The race engine dropped to approx. 65% volumetric when it warmed up. If I could get that 35% back plus, wow the boat wouldn't have stayed together.

[knot<safe77]

Thanks for that info. Your the real mcoy with the experience and u also said that was1970s technology u would love to do it again with today's technology and see the final product. Everyone thinks these problems still exist.... the import game is hugee. And more young people and builders are into rotaries then ever.. Florida Australia and puerto rico they are flooded with rotaries and they are fasttttt... its not leaving any time soon that's for sure... I hate when people say it was a waist what you guy's accomplished, you guys did a great job. And i hope someone picks your brain enough that itwil be atattempted again. Awesome thread.

[Big Steve 435]

[QUOTE=Speedfab

I'll take Rotary John's real life knowledge of these things over internet armchair quarterbacks and rotary fanboys all day. I may have many years of experience with them, I may be an engineer, but he actually ENGINEERED one. Big difference. I'm not just blowing smoke, I think everyone reading this needs to realize how fortunate we are that he is actually here telling us about it. I find the whole thing fascinating.[/QUOTE]

Let me set the table and tell you of what I remember as a kid
of the Greatest Parker Race Ever!

I grew up in a family, full of mechanics.
Starting back to Barney Oilfield / Henry Ford

My Father and partner had been asked by Shelby to work with them. Joe Mondello worked down the street and went on to win the Enduro

Well we were all VIP guests of Mc Culloch oil for the race.
Jack was Robert Mc Culloch's "special projects" guru

Jack along with Ak Miller won the "Pan American" road race.

Ford, gave Miller a 25 million grant job designing the FE ford motor platform.

Jack, was amazing, build a city, move a bridge, supercharger, 2-stroke motors, promote boat racing. And a mentor

This Parker race was about winning. Ford, Chev, Mopar
had vested stakes. Win on Sunday sell on Monday !

But, to Mercury
It's about crushing you opponent !

Well life is about the little things

Like a "David vs Goliath" moment.

You don't see them often.

That's why we are still talking about it to this day.

My brother and I learned something that day !
First, we want a Rotary.
Second, we want to win that race someday.
Well, we did the latter.

And we still want a rotary
It was the little train that could !

Big Steve

[Speedfab]

The race engine dropped to approx. 65% volumetric when it warmed up. If I could get that 35% back plus, wow the boat wouldn't have stayed together.

What do you think caused that? Sealing? Inlet air temps? Cooling hot spots? That's a huge hit.

Big Steve, I totally get what you mean. We must be about the same age or close. My dad was small time into boat racing, only stuff I ever saw was in Florida as far as I know. But I did get to see and hear stackers run in their heyday, along with some other neat stuff. I look back glad that I was at least born early enough to witness what to me were the great days of outboard racing.

[Rotary John]

What do you think caused that? Sealing? Inlet air temps? Cooling hot spots? That's a huge hit.

Big Steve, I totally get what you mean. We must be about the same age or close. My dad was small time into boat racing, only stuff I ever saw was in Florida as far as I know. But I did get to see and hear stackers run in their heyday, along with some other neat stuff. I look back glad that I was at least born early enough to witness what to me were the great days of outboard racing.
These engines were charged cooled. Meaning the fuel/air intake charge went thru the internals of the rotor first and then into the intake cycle. The charge heated up approx. 150 F in the process and thus expanded resulting in a lower volumetric. In addition the intake path was quite tortuous resulting in further loses. This is how the rotor bearing was lubricated also, The delta T across the rotor cause the bearing to be larger on the hot side than the cold side, resulting in hugh side loading and premature failure, Mazda engines are oil cooled and can allow for direct intake to the intake cycle resulting in 100+ volumetric. If you look at the Mazda LaMans engine, it had variable length intake horns to maximize volumetric thru out the rpm range.

[Rotary John]

Let me set the table and tell you of what I remember as a kid
of the Greatest Parker Race Ever!

I grew up in a family, full of mechanics.
Starting back to Barney Oilfield / Henry Ford

My Father and partner had been asked by Shelby to work with them. Joe Mondello worked down the street and went on to win the Enduro

Well we were all VIP guests of Mc Culloch oil for the race.
Jack was Robert Mc Culloch's "special projects" guru

Jack along with Ak Miller won the "Pan American" road race.

Ford, gave Miller a 25 million grant job designing the FE ford motor platform.

Jack, was amazing, build a city, move a bridge, supercharger, 2-stroke motors, promote boat racing. And a mentor

This Parker race was about winning. Ford, Chev, Mopar
had vested stakes. Win on Sunday sell on Monday !

But, to Mercury
It's about crushing you opponent !

Well life is about the little things

Like a "David vs Goliath" moment.

You don't see them often.

That's why we are still talking about it to this day.

My brother and I learned something that day !
First, we want a Rotary.
Second, we want to win that race someday.
Well, we did the latter.

And we still want a rotary
It was the little train that could !

Big Steve
It happened again at Provo. Merc brought all their big guns including 600HP IO's trying to compete with the rotary. They went home with there tail between their legs.

[jackiewilson]

It happened again at Provo. Merc brought all their big guns including 600HP IO's trying to compete with the rotary. They went home with there tail between their legs.
C'mon Johnno, you cannot be serious, one quick first lap at Parker-----what happened to the mighty ROTORY the next time round,---stopped for a drink and a sandwich did we?
6 wins out of eight starts 40 + years ago and your still celebrating ,----3of those were at backyard events with minimum opposition
Windermere was by default after the opposition broke, hells teeth I was in the first five with a 1000 BP, DRIVING SO SLOW GG SACKED ME.
Never been to Provo, but every time WILLABEE and you get into it there is conflicting memories of the event.
Mercury probably won over 1,000 races worldwide that year (' cos that's what they do ) hell of a lot more than 6.

[jackiewilson]

Oh I forget Johnno, where in the hell could you find a V8 that got anywhere near 600hp---------be lucky to get any more than 300, and that's pushing it. (In my opinion).

[STEVERINO]

C'mon Johnno, you cannot be serious, one quick first lap at Parker-----what happened to the mighty ROTORY the next time round,---stopped for a drink and a sandwich did we?
6 wins out of eight starts 40 + years ago and your still celebrating ,----3of those were at backyard events with minimum opposition
Windermere was by default after the opposition broke, hells teeth I was in the first five with a 1000 BP, DRIVING SO SLOW GG SACKED ME.
Never been to Provo, but every time WILLABEE and you get into it there is conflicting memories of the event.
Mercury probably won over 1,000 races worldwide that year (' cos that's what they do ) hell of a lot more than 6. First of all Jackie I never new you were so talented with these works of art they look pretty good to me I would like to see pictures of all of them..Now thinking back to the Windermere Grand Prix of 1973 was the year the Rotarys won.The little black 1000SBP Molinari sprint boat you ran at Windermere was in 1971?

[jackiewilson]

[QUOTE=STEVERINO;2604540]First of all Jackie I never new you were so talented with these works of art they look pretty good to me I would like to see pictures of all of them..Now thinking back to the Windermere Grand Prix of 1973 was the year the Rotarys won.The little black 1000SBP Molinari sprint boat you ran at Windermere was in 1971?[/QUOTE

If that's the year Shakey copped it then your right Steve, didn't race at all in 1973 so I owe R/J a huge unreserved apology-------big Mouth WILSON. The little grey cells are turning white.

[Rotary John]

[QUOTE=STEVERINO;2604540]First of all Jackie I never new you were so talented with these works of art they look pretty good to me I would like to see pictures of all of them..Now thinking back to the Windermere Grand Prix of 1973 was the year the Rotarys won.The little black 1000SBP Molinari sprint boat you ran at Windermere was in 1971?[/QUOTE

If that's the year Shakey copped it then your right Steve, didn't race at all in 1973 so I owe R/J a huge unreserved apology-------big Mouth WILSON. The little grey cells are turning white.
Jackie: I thought for a moment you were so slow with that Merc BP that you were still trying to finish in '73 having started in '71. Seems to me it was you a few posts ago saying 100HP from a V-8? Karl used to line them up on the dock just to prove they were available; 600 HP marine V-8's. Hell damn; you can get that much HP today in a Corvette that's emission legal.

[jackiewilson]

[QUOTE=jackiewilson;2604555]
Jackie: I thought for a moment you were so slow with that Merc BP that you were still trying to finish in '73 having started in '71. Seems to me it was you a few posts ago saying 100HP from a V-8? Karl used to line them up on the dock just to prove they were available; 600 HP marine V-8's. Hell damn; you can get that much HP today in a Corvette that's emission legal.

That's today Johnno, Doubt if a Keith Black lump would give 300 in 1972.
Reason I was slow , Shakey Bill had just disappeared into the depths of Windermere ( to be discovered 20 years later) and my heart was not in it.
that is what GG and I had the argument about, it came close to a fist fight and I got thrown out of
the brownies.

[ndwoods]

Back in the 70's, I was in Key West. A outboard race was held in a small bay between Boog Powels Marine and Boca Chica key. I atched from a spit ofdry land at Boogs. The guys in black were present with the big factory haulers. All the black motors had cow bells and sounded awesome. The OMC guys had one boat and it was plain jane. The race started and boy what a surprise. The start was even and the turn speeds were even but on the straights it looked like the Merc's threw out a sea anchor. I knew about the Mazda engine but had no idea some gear heads had bolted it to a transom. They lapped the field several times until something put a hole in the hull and a stream of water shot up through the cockpit. Some how the driver got it into the shallows close to where I was. The crew all jumped in and kept the power head above water and saved it. Thanks for the history and evolution of the marine rotary. After the above event I never heard anything else about it. I often mentioned this to other folks and usually got a are you crazy look.

[FUJIMO]

Back in the 70's, I was in Key West. A outboard race was held in a small bay between Boog Powels Marine and Boca Chica key. I atched from a spit ofdry land at Boogs. The guys in black were present with the big factory haulers. All the black motors had cow bells and sounded awesome. The OMC guys had one boat and it was plain jane. The race started and boy what a surprise. The start was even and the turn speeds were even but on the straights it looked like the Merc's threw out a sea anchor. I knew about the Mazda engine but had no idea some gear heads had bolted it to a transom. They lapped the field several times until something put a hole in the hull and a stream of water shot up through the cockpit. Some how the driver got it into the shallows close to where I was. The crew all jumped in and kept the power head above water and saved it. Thanks for the history and evolution of the marine rotary. After the above event I never heard anything else about it. I often mentioned this to other folks and usually got a are you crazy look.
Good to hear a story from someone who was there then, even though it had an anticlimax. And...Welcome to Scream & Fly ndwoods.:smiletest:

[Mark Poole ModVP]

Jackie, a CCC V6 was probably close to 300 hp (the later versions) Something that many people don't know is that the OMC 235 production motor pulled more than 235 h.p. when it was introduced. Scared the crap out of Merc as they were sure OMC had only built a 200 h.p. engine. The later fuel injected V8 had to be cranking some serious power for Benny to do a 141 mph lap in 1986.

No doubt the rotary and the V8 helped sink OMC. The rotary project was rumored to have started in 1967 so from then until 1973 must have gone through a crap load of money. A former OMC employee told me they were spending a million $ per race for the U.S. F1 series. Fun while it lasted I guess.

[jackiewilson]

Jackie, a CCC V6 was probably close to 300 hp (the later versions) Something that many people don't know is that the OMC 235 production motor pulled more than 235 h.p. when it was introduced. Scared the crap out of Merc as they were sure OMC had only built a 200 h.p. engine. The later fuel injected V8 had to be cranking some serious power for Benny to do a 141 mph lap in 1986.

No doubt the rotary and the V8 helped sink OMC. The rotary project was rumored to have started in 1967 so from then until 1973 must have gone through a crap load of money. A former OMC employee told me they were spending a million $ per race for the U.S. F1 series. Fun while it lasted I guess.
Mark, I had 400hp and could run 125 for a week, @8,500 rpm, at that exact speed the front port sponson got well and truly out of shape. Always felt the set up would run 150+ if we could iron the problem! but it was a very short exercise, (mainly to test US reaction to the Cosworth motor) the whole project lasted less than a year, but was fun while it lasted -----whole project probably cost less than a batch of ROTORY cranks.

[powerabout]

what was the then retail price of DFV?
PS you can make 250hp from a 2.0 v4 looper with stock parts, that tends to say 500 with a behind the liner straight in front half 3.5ltr wouldnt be hard..

[jackiewilson]

what was the then retail price of DFV?
PS you can make 250hp from a 2.0 v4 looper with stock parts, that tends to say 500 with a behind the liner straight in front half 3.5ltr wouldnt be hard..
£25,000 ----under. $.40,000

[STEVERINO]

:iagree:
£25,000 ----under. $.40,000. I can remember BIll Badsey in 1977 being quoted £5,000 for a OMC. 2.5 CCC engine.

[jackiewilson]

:iagree:. I can remember BIll Badsey in 1977 being quoted £5,000 for a OMC. 2.5 CCC engine.

Be honest Steve-----which would you rather have, 5 x 2.5 CCC OR ONE EVERLASTING COSWORTH DFV----- no contest is it ..?

[STEVERINO]

Be honest Steve-----which would you rather have, 5 x 2.5 CCC OR ONE EVERLASTING COSWORTH DFV----- no contest is it ..?. To be honest Jackie the Cosworth engine had a massive part to play in the history of formula 1 car racing that it would be no contest but I wish I still had that outfit today I would just like to go out and drive it. In 1978 at the World OZ championship race in the UK I am sure you finished 4th place and I finished in 5th place overall not bad to say my engine had raced about 5 international races maybe 20 hrs until I sold it.The engines that finished in the first 3 places were that highly tuned they were lucky to finish 3 hrs of racing.Going back to a earlier post about the Windermere 3hr Grand Prix in 1971 I have been trying to find Ray Bulmans race report from 1971?.

[jackiewilson]

. To be honest Jackie the Cosworth engine had a massive part to play in the history of formula 1 car racing that it would be no contest but I wish I still had that outfit today I would just like to go out and drive it. In 1978 at the World OZ championship race in the UK I am sure you finished 4th place and I finished in 5th place overall not bad to say my engine had raced about 5 international races maybe 20 hrs until I sold it.The engines that finished in the first 3 places were that highly tuned they were lucky to finish 3 hrs of racing.Going back to a earlier post about the Windermere 3hr Grand Prix in 1971 I have been trying to find Ray Bulmans race report from 1971?.

GG and Duckworth wanted Billy to try my boat, did a few laps and didn't go any quicker than me---------the boat was the limiting factor, not the motor.
Was full factory nose to nose at time and all the secret sh-t was there.
Better get off R/J site, he can get prissy real easy.

[olboatman]

Scribed. Gary

[jackiewilson]

Where are you Jonno?

[Rotary John]

Where are you Jonno?
I'm still here. Just nothing good to ad.

[powerabout]

John
When was the move to oil cooled ones that allowed peripferal ports?
Cheers

[SCT]

John, how many rotary engines were made by OMC?

[powerabout]

Cobalti
Was the guy in Melbourne
I'll find a photo
Cheers
edit
photo

[lars strom]

Back on topic..!!!!!


OMC and the Rotary outboard took the overall win in Windermere 1973


http://svera.se/blogg/omc-and-the-rotary-outboard-took-the-overall-win-in-windermere-1973/ (http://svera.se/blogg/omc-and-the-rotary-outboard-took-the-overall-win-in-windermere-1973/)

[Rotary John]

John
When was the move to oil cooled ones that allowed peripferal ports?
Cheers
The oil cooled engines were actually the first ones OMC worked on. It was 100ci; 210HP in both outboard and IO. They were peripheral ported and were actually pretty good engines. However, cost was much more than a 2-stroke of the time and even after a complete redesign for cost, it still wasn't competitive. The 32ci engine was designed for the snowmobile and was air cool/charged cooled. The race engine was the water cooled variant of the snowmobile engine. Go back to the start of this thread and it tell the whole story.

[Rotary John]

John, how many rotary engines were made by OMC?
OMC produced approx. 15,500 snowmobile engines in 1973-74. Though several other engines were developed, the SN engine was the only one ever in production. OMC stopped rotary development in 75/76. I believe OMC research worked on a larger engine after that, but never got it to work properly. By that time all of the engineering people in Waukegan had left.

[Rotary John]

Back on topic..!!!!!


OMC and the Rotary outboard took the overall win in Windermere 1973


http://svera.se/blogg/omc-and-the-rotary-outboard-took-the-overall-win-in-windermere-1973/
If you look closely, the bottom half of the engine (bucket) is silver (Evinrude). For some reason I don't remember, An Evinrude engine was mounted on the Downard/Posey boat and shroud was switched to make it a Johnson.

[2us70]

For all you rotary enthusiasts there are several YouTube videos on building rotaries.

[powerabout]

The oil cooled engines were actually the first ones OMC worked on. It was 100ci; 210HP in both outboard and IO. They were peripheral ported and were actually pretty good engines. However, cost was much more than a 2-stroke of the time and even after a complete redesign for cost, it still wasn't competitive. The 32ci engine was designed for the snowmobile and was air cool/charged cooled. The race engine was the water cooled variant of the snowmobile engine. Go back to the start of this thread and it tell the whole story.
Ok re read it all, thanks John, I see Moller are doing what they are doing with a charge cooled engine, is that right?

[Rotary John]

Ok re read it all, thanks John, I see Moller are doing what they are doing with a charge cooled engine, is that right?
Moller is using the 538 OMC base engine. Charged cooled/water cooled. He has developed a central web rotor with dual intakes. He also does direct oil injection to the bearings. He tells me he is getting 105HP from a single rotor engine. Knowing what I know of the exhaust system and porting on the 4 rotor, I would estimate 450+ HP for a todays 4 rotor. I would love to see one of them on a current race boat. Look out Merc, Again.

[jackiewilson]

Moller is using the 538 OMC base engine. Charged cooled/water cooled. He has developed a central web rotor with dual intakes. He also does direct oil injection to the bearings. He tells me he is getting 105HP from a single rotor engine. Knowing what I know of the exhaust system and porting on the 4 rotor, I would estimate 450+ HP for a todays 4 rotor. I would love to see one of them on a current race boat. Look out Merc, Again.

Why Johnno, nobody out there has "UNLIMITED" cash any more, it still wouldn't be enough to touch the 1,000 hp a formula 1 motor produces to day, proven , in production , successful and viable, all from 3 liters.

[powerabout]

I'll bet they could if the spentOTE=jackiewilson;2611544]Why Johnno, nobody out there has "UNLIMITED" cash any more, it still wouldn't be enough to touch the 1,000 hp a formula 1 motor produces to day, proven , in production , successful and viable, all from 3 liters.[/QUOTE]
I'll bet they could if they spent the 2-3 hundred million each year that F1 does just on the engine
This year is an all new engine, lets see how reliable they are for $200 mil
Which means they will have spent a billion in 5 years

[powerabout]

Why Johnno, nobody out there has "UNLIMITED" cash any more, it still wouldn't be enough to touch the 1,000 hp a formula 1 motor produces to day, proven , in production , successful and viable, all from 3 liters.
Jackie they havnt been 3 ltr nor 1000hp for years

[jackiewilson]

Jackie they havnt been 3 ltr nor 1000hp for years

That's what I was trying to say -----you do not need capacity to raise H.P. progress has been made everywhere except in rotaries.
I still think the design is fatally flawed somewhere.

[jackie wilson]

According to Ferrari blurb they have available 26,000 RPM but will limit output to 15,600 so as to make the motor last for the required 5,000 race miles, this is from a 1.5 turbo lump which produces some 750 HP with a further 160 for 20 seconds from the KERS -----thats over 900 HP and the season has only just begun, by 2015 it will be back up to 1,000 again.
I do not agree with the current formula at all ----- you can get 1,000,000 HP for a brief moment going down this road, it' just a very expensive balancing act.

[powerabout]

Tell you something very interesting I read the other day comparing a nascar 6.0 ltr and the just replaced 2.5 f1 v8
Many things similar as in they are both at their design peaks etc

[jackiewilson]

Tell you something very interesting I read the other day comparing a nascar 6.0 ltr and the just replaced 2.5 f1 v8
Many things similar as in they are both at their design peaks etc

They said that about the Coventry Climax in 1939, same thing when Mercury brought out 100 HP, but it seems progress marches on in everything ( except the ROTORY it seems).

[STEVERINO]

If you look closely, the bottom half of the engine (bucket) is silver (Evinrude). For some reason I don't remember, An Evinrude engine was mounted on the Downard/Posey boat and shroud was switched to make it a Johnson. Hi John just curious to ask were you at the Windermere Race in 1973 when the Rotaries ran` my memories pretty good for this race my co driver in the Paris 6hr race 2 weeks before the Windermere race had wrecked our new boat and we only just made the race as we had to repaint and fit out a 4yr old boat to use and I remember how old it looked against the new boats and how slow it ran.The sound of those Rotaries would not have been out of place on a airfield I thought they had a very Gruff exhaust note I can remember James Beard had his new Cougar fitted with one and I stood in the pits when he set off for practise and boy did he have lift off.Now I know we were not used to anything over 99cu in` so it did seam impressive at the time whats your take on this you would have watched them testing at Brugge I know Beards Cougar was a smaller boat and lighter than those Scottis.Now back to the race I remember rounding the bottom turn buoy and Beards Cougar passing me on the outside he was very close and his boat was really twitching from side to side under hard acceleration it did look a rather lively drive.When you were at Brugge did the drivers that were doing the testing give you any feedback comparing the different power deliveries with the 2.0V6 engines against the Rotaries?.

[2us70]

An open exhaust wankel rotary is one UNPLEASANT sounding engine. It doesn't matter weather you put it in a car, an outboard motor or an airplane. I have heard them in all of those applications and they are nasty. The v-10 viper motors are only a little better in my opinion.

[Rotary John]

Hi John just curious to ask were you at the Windermere Race in 1973 when the Rotaries ran` my memories pretty good for this race my co driver in the Paris 6hr race 2 weeks before the Windermere race had wrecked our new boat and we only just made the race as we had to repaint and fit out a 4yr old boat to use and I remember how old it looked against the new boats and how slow it ran.The sound of those Rotaries would not have been out of place on a airfield I thought they had a very Gruff exhaust note I can remember James Beard had his new Cougar fitted with one and I stood in the pits when he set off for practise and boy did he have lift off.Now I know we were not used to anything over 99cu in` so it did seam impressive at the time whats your take on this you would have watched them testing at Brugge I know Beards Cougar was a smaller boat and lighter than those Scottis.Now back to the race I remember rounding the bottom turn buoy and Beards Cougar passing me on the outside he was very close and his boat was really twitching from side to side under hard acceleration it did look a rather lively drive.When you were at Brugge did the drivers that were doing the testing give you any feedback comparing the different power deliveries with the 2.0V6 engines against the Rotaries?.
Yes I was at Windermere and Brugge for set up. I remember Beards boat as it was the first time he had it in the water and it had stepped sponsons. The Scotties were older boats. The rotary had a lot more HP particularly at the lower RPM range than the V-6 of the time and would out accelerate them. I think Sanders said the 2-engine Merc was the only thing that gave you the "push" of the rotary.

[jackiewilson]

Yes I was at Windermere and Brugge for set up. I remember Beards boat as it was the first time he had it in the water and it had stepped sponsons. The Scotties were older boats. The rotary had a lot more HP particularly at the lower RPM range than the V-6 of the time and would out accelerate them. I think Sanders said the 2-engine Merc was the only thing that gave you the "push" of the rotary.

Well if the maths are to be believed-----seems quite a simple sum to me 2x2litre outboards = one four litre ROTORY, Horsepower should be around 400 for each, yeah I can agree to that, the "Push" factor would be pretty close, 'bout the same as the Cosworth I would say Johnno, I could always come out of the hole first, felt like I had push AND pull.

[T2x]

I wonder how the rotaries would have fared against the V8's in performance?

[powerabout]

I guess you would have to move a generation forward such as the Moller and find out with all the new tools, FEA CFD and EFI etc. what can be achieved?
John wrote somewhere how much HP the Moller ones are I think he said 300 for 2 rotor so 4 would be 600 and you dont have to change the rod bolts every heat.

[Rotary John]

I guess you would have to move a generation forward such as the Moller and find out with all the new tools, FEA CFD and EFI etc. what can be achieved?
John wrote somewhere how much HP the Moller ones are I think he said 300 for 2 rotor so 4 would be 600 and you dont have to change the rod bolts every heat.
I eliminated the crank bolt on the latest version. Also added 2 center main bearings while reducing weight by 20 lbs. Never broke the new setup. Moller is getting 105 Hp from a single which would give approx. 450 from a 4. I don't know what hp the race V-8 had at the time; Nerstrom would know. I could always add 2 more rotors (3 l) and get 600 HP.

[Rotary John]

Well if the maths are to be believed-----seems quite a simple sum to me 2x2litre outboards = one four litre ROTORY, Horsepower should be around 400 for each, yeah I can agree to that, the "Push" factor would be pretty close, 'bout the same as the Cosworth I would say Johnno, I could always come out of the hole first, felt like I had push AND pull.
Jackie: I guess I can never teach you anything about a rotary. My engine was 2 l; not 4. Its measured just like the 2-strokes; displaced volume per crank revolution.

[jackiewilson]

Jackie: I guess I can never teach you anything about a rotary. My engine was 2 l; not 4. Its measured just like the 2-strokes; displaced volume per crank revolution.

Tell me again how you measure the ROTORY Johnno , if I remember rightly this was always a bone of contention, I also loved to buck the establishment, and the best feeling in the world was to Stuff it to the factories.

[whipper]

Theres a guy who has finally figured out all the flaws with these rotorys and has been experimenting with the combustion flaws and spark. It looks like there going to give it another go. This time looks promising that the stroke can have a much better compression and combustion making them way more efficient. Ernie Brink http://www.youtube.com/watch?v=m3pCLjHZmhM

[Rotary John]

Theres a guy who has finally figured out all the flaws with these rotorys and has been experimenting with the combustion flaws and spark. It looks like there going to give it another go. This time looks promising that the stroke can have a much better compression and combustion making them way more efficient. Ernie Brink http://www.youtube.com/watch?v=m3pCLjHZmhM
As with most shade tree mechanics, this one doesn't have a clue what he's talking about. The leading spark plug hole is positioned where the pressures are equal on either side of the apex seal. and if it has a trailing plug, it has a shooting hole which is smaller than the apex seal. In fact the original Wankel didn't have any spark plug holes as the plug was in the rotor face. The leading pocket has been used for years, but his contention that it aids rotation is crap. Combustion pressure acting thru the center against the eccentric is what gives it torque. It would be like saying an offset combustion chamber on a piston engine would give more power because it puts combustion pressure on the good side of the crank throw.

[Rotary John]

Tell me again how you measure the ROTORY Johnno , if I remember rightly this was always a bone of contention, I also loved to buck the establishment, and the best feeling in the world was to Stuff it to the factories.
Its measured just like the 2-strokes; displaced volume per crank revolution.

[Mark75H]

I thought 2 strokes were measured piston displaced volume times number of cylinders/pistons?

[Rotary John]

I thought 2 strokes were measured piston displaced volume times number of cylinders/pistons?
And just what is displaced volume????

[2us70]

Where exactly in the rotation cycle are the starting and end points for measuring the individual chamber displacement and compression ratios?

[Rotary John]

Where exactly in the rotation cycle are the starting and end points for measuring the individual chamber displacement and compression ratios?
Min vol is at TDC; max vol happens when the crank is at 90 degrees; dis placed vol = max - min

[2us70]

And that happens 3 times per revolution per rotor right? So each rotor equals a 3 cyl motor? A 4 rotor is like running a 12 cylinder 2 stroke.

[jackiewilson]

So Johnno, the question still remains,how do you measure the capacity or can you even measure it to compare to any other motor. Me, I'm a simple minded chap with only a basic maths understanding but a modicum of common sense, I can add and subtract (still) and even I can see with the minimum amount of movement the Wankel SHOULD BE A WINNER but a hundred years on nobody has taken up the cudgel and produced a cost effective " profitable " piece of propulsion , whilst Every other form of motor from two stroke to jet and all points between continue to develop.
like I said before Johnno-----THE DAMN THING IS FATALLY FLAWED. FIND THE FLAW YOU HAVE A WINNER.

[powerabout]

So Johnno, the question still remains,how do you measure the capacity or can you even measure it to compare to any other motor. Me, I'm a simple minded chap with only a basic maths understanding but a modicum of common sense, I can add and subtract (still) and even I can see with the minimum amount of movement the Wankel SHOULD BE A WINNER but a hundred years on nobody has taken up the cudgel and produced a cost effective " profitable " piece of propulsion , whilst Every other form of motor from two stroke to jet and all points between continue to develop.
like I said before Johnno-----THE DAMN THING IS FATALLY FLAWED. FIND THE FLAW YOU HAVE A WINNER.
didnt Mazda spend a bit and clean up in LeMans once?

[Rotary John]

And that happens 3 times per revolution per rotor right? So each rotor equals a 3 cyl motor? A 4 rotor is like running a 12 cylinder 2 stroke.
NO! It only happens once per revolution. That's the point. It displaces its "displaced volume " ONCE per revolution on the crank. Search Wankel if you need to see how one works.

[Rotary John]

didnt Mazda spend a bit and clean up in LeMans once?
Yes> They ran a 4-rotor engine and won Lemans. They were so dominant, they were banned. Boy does that sound familiar.http://ts1.mm.bing.net/th?id=HN.608051143083035648&w=255&h=179&c=7&rs=1&qlt=80&pe=1&mo=10_30&pid=1.7

[Rotary John]

So Johnno, the question still remains,how do you measure the capacity or can you even measure it to compare to any other motor. Me, I'm a simple minded chap with only a basic maths understanding but a modicum of common sense, I can add and subtract (still) and even I can see with the minimum amount of movement the Wankel SHOULD BE A WINNER but a hundred years on nobody has taken up the cudgel and produced a cost effective " profitable " piece of propulsion , whilst Every other form of motor from two stroke to jet and all points between continue to develop.
like I said before Johnno-----THE DAMN THING IS FATALLY FLAWED. FIND THE FLAW YOU HAVE A WINNER.
Oh Jackie: I guess I'll never teach you. You can't "measure" a rotary engine displacement without knowing some basic geometry. Then its simple to calculate. Displacement arguments also come about because a 4-stroke engine requires 2 complete revolutions of the crank to complete 1 cycle. A 2-stroke or Wankel completes its cycle with one revolution of the crank. Only recently has there been any discussion on how to compare 2-stroke and 4- stroke displacement. Its always been bore area x stroke; regardless of how many times the crank goes around. It gets down to politics and taxes on how you rate displacement. You are correct on one inherent flaw and that is large surface to volume ration. This leads to surface quenching of the charge and HC emissions. However, the opposite is true of NOx. The slow flame propagation results in inherently lower NOx emissions. Now with that said, When was the last time you saw emission testing required on race engines? As I said politics and taxes.

[jackiewilson]

Min vol is at TDC; max vol happens when the crank is at 90 degrees; dis placed vol = max - min
This where my common sense thinking says to me---if max volume is at 90degrees, What happens in the other 270degrees----doesn't that count?
Displaced volume= max- min, why would you bother to include. - min, is minimum still counted, ' cos if it's not, why bother to put it there anyway, unless it's to blind me with science.
just my simple mind trying to understand what I should not be anywhere near in the first place.

[2us70]

Any way you slice it a four rotor rotary produces 12 power pulses per revolution right? A 4 cyl two stroke produces 4 power pulses per rev and a four stroke makes only 2. This would appear to account for the power advantage of the rotary and also its fuel economy disadvantage.

[powerabout]

Any way you slice it a four rotor rotary produces 12 power pulses per revolution right? A 4 cyl two stroke produces 4 power pulses per rev and a four stroke makes only 2. This would appear to account for the power advantage of the rotary and also its fuel economy disadvantage.
you cant have it both ways bsfc is how you measure it
4 stroke outboard heavier less torque and why would you buy one? How come a v6 DI 2 stroke firing twice as often competes with one?

[Rotary John]

Any way you slice it a four rotor rotary produces 12 power pulses per revolution right? A 4 cyl two stroke produces 4 power pulses per rev and a four stroke makes only 2. This would appear to account for the power advantage of the rotary and also its fuel economy disadvantage.
Wrong again. A 4-rotor Wankel produces 4 power strokes per revolution; just like a 2-stroke. The power advantage comes from the fact the power stroke lasts for approx. 270 degrees of crank rotation where as a 2&4-stroke last for less than 90. A piston engine can increase its Comp. ratio by reducing the combustion chamber size. A rotary however is limited to max compression ratio by geometry. The fuel economy disadvantage is cause primarily by the long distance the flame front must travel and as said before the greater surface to vol ratio. I must say however, we were able to get the racing rotary to a BSFC of .385 where as a typical 2-stroke is .8. 4-strokes are typically .5. WE forced the race engine to run at .6 trying to keep the rotor bearing alive.

[Rotary John]

I would think in todays environmental situation racing classes should be driven by fuel quantity, not displacement. That way the pissing contest over how do you measure displacement goes away and forces engine people to concentrate on specific fuel consumption instead.

[jackiewilson]

I would think in todays environmental situation racing classes should be driven by fuel quantity, not displacement. That way the pissing contest over how do you measure displacement goes away and forces engine people to concentrate on specific fuel consumption instead.

The Duckworth formula for racing was ----a100 mile race 2gallons of fuel and run what you like!,

[Rotary John]

The Duckworth formula for racing was ----a100 mile race 2gallons of fuel and run what you like!,
Jackie: Heaven forbid; we actually agree on something.

[Bob V]

The Duckworth formula for racing was ----a100 mile race 2gallons of fuel and run what you like!,

My entry....A dinghy with a British Seagull motor and a strong tailwind :eek:

[jackiewilson]

Jackie: Heaven forbid; we actually agree on something.

Morning Johnno, we are not so very different underneath. Big difference is you are an engineer and can understand the principles of motors and propulsion and delve into the intricacies , none of which is within my comprehension (especially Rotors).
Lodically a wankel should be made in millions------but to me there is a huge basic flaw and the motor makers must think so too.
Waiting for the excreta,???

[Instigator]

Wrong again. A 4-rotor Wankel produces 4 power strokes per revolution; just like a 2-stroke. The power advantage comes from the fact the power stroke lasts for approx. 270 degrees of crank rotation where as a 2&4-stroke last for less than 90. A piston engine can increase its Comp. ratio by reducing the combustion chamber size. A rotary however is limited to max compression ratio by geometry. The fuel economy disadvantage is cause primarily by the long distance the flame front must travel and as said before the greater surface to vol ratio. I must say however, we were able to get the racing rotary to a BSFC of .385 where as a typical 2-stroke is .8. 4-strokes are typically .5. WE forced the race engine to run at .6 trying to keep the rotor bearing alive.

Very interesting information that I did not realize about the rotaries. Especially the flame travel. That would be a tough nut to crack.
I was always suspect of the mass of the rotors at speed :eek:

Speaking of fuel economy, you may be interested to know that Formula One car racing just did a complete re-write of their engine tech rules for this year.
The new motors are turbo charged, 1.6 liter V-6's w/a 14K rev limit and a 100kg fuel allotment per race. The FIA mandates use of fuel sensors to monitor this.
They are also using an electric motor system worth I think 160 HP's that partially recharges during braking.
Neat stuff but I like the classes that have no rules/limits.
Let the thinkers think and leave the fuel efficiencies to be shoved down our throats by our trusty government.


Being F-1 though, it is fun to watch the most brilliant minds in the world figure out how to make it all stupid fast ;)
The FIA is claiming a 30% reduction in fuel from last season.

[jackiewilson]

Don't agree with you on "no limits" leads to large portions of disagreements and nowhere to race and law suits and court orders and bunches of fall out between friends-----BAD IDEA!!!

Every company and association has lied about fuel saving since Pontous was a pilot, so you can take that with a pinch of cheese and biscuits.

Be very careful on this thread Gary----It's the home of a giant of a man ------BIG JOHN,,!!

[Instigator]

Don't agree with you on "no limits" leads to large portions of disagreements and nowhere to race and law suits and court orders and bunches of fall out between friends-----BAD IDEA!!!

Maybe no rules was too broad of a statement. How about "basic" rules?

When I ran Stock Outboard the motors were to be raced as manufactured. In Pro O/B, the only limits were on displacement.
In Stock we all compared notes on how to best build a KG-4, MK 15, a 20 H etc. In Pro they said OK, we can only be X # cu.in's (CC's for you Jackie ;) ) or less but thats the rules so let us think....., humh........
The guy that dominated 500cc and set every record for yrs figured out how to take four 125cc, single cylinder MX jugs and graft them to a custom made four cylinder case and "created" a 500cc four cylinder, horizontally opposed monster.
It's different too if it's not a mfg trying to sell on Monday.

Formula One car racing used to be that class. It is turning into a green class.
Last year they ran naturally asperated 2.4 liter V-8's w/a 18K rev limit which was down from a previous 22K! Think about that valve train at 22 K!
If you allow the thinkers to think, they will.

I understand the cost aspect but these guys are way beyond that and most of us liked the class because we saw stuff that was Star Wars level technology. Beyond NASA.
A true gear head wants to see the baddest mammer jammers on the planet. Period and no excuses.
There are other classes for rules but give us one with none.

I think Mod U was close to that even though most of their records were equal to or bellow the Champ/F-1 records.
How do we know w/o trying?

One of my hero's, Smokey Yunick (research him Jackie, you'll like what you read) used to say if your motor was still running past the finish line, you didn't modify it enough ;)

[jackiewilson]

Maybe no rules was too broad of a statement. How about "basic" rules?

When I ran Stock Outboard the motors were to be raced as manufactured. In Pro O/B, the only limits were on displacement.
In Stock we all compared notes on how to best build a KG-4, MK 15, a 20 H etc. In Pro they said OK, we can only be X # cu.in's (CC's for you Jackie ;) ) or less but thats the rules so let us think....., humh........
The guy that dominated 500cc and set every record for yrs figured out how to take four 125cc, single cylinder MX jugs and graft them to a custom made four cylinder case and "created" a 500cc four cylinder, horizontally opposed monster.
It's different too if it's not a mfg trying to sell on Monday.

Formula One car racing used to be that class. It is turning into a green class.
Last year they ran naturally asperated 2.4 liter V-8's w/a 18K rev limit which was down from a previous 22K! Think about that valve train at 22 K!
If you allow the thinkers to think, they will.

I understand the cost aspect but these guys are way beyond that and most of us liked the class because we saw stuff that was Star Wars level technology. Beyond NASA.
A true gear head wants to see the baddest mammer jammers on the planet. Period and no excuses.
There are other classes for rules but give us one with none.

I think Mod U was close to that even though most of their records were equal to or bellow the Champ/F-1 records.
How do we know w/o trying?

One of my hero's, Smokey Yunick (research him Jackie, you'll like what you read) used to say if your motor was still running past the finish line, you didn't modify it enough ;)


Yup up can go along with that,!! UIM have all that, free every thing ----except limited capacity is the O series.
Unlimited everything is OZ ----the death knell of powerboat racing.
Then there is the EX class for things like ROTORIES and Jets, and turbines.
So you see ,most things are covered.
Mario Andretti used to say ----if you hadn't crapped your knickers during the race, you weren't trying hard enough.
James Hunt used to say " if it moves, screw it" don't neccesarilly agree with that one.

[lars strom]

Round two to the rotaries – first major win for OMC at Galveston Classic 1973


Very good reading with pictures. Powerboat Magazine July 1973. Click link below.


http://svera.se/blogg/round-two-to-the-rotaries-first-major-win-for-omc-at-galveston-classic-1973/

[powerabout]

Maybe no rules was too broad of a statement. How about "basic" rules?

When I ran Stock Outboard the motors were to be raced as manufactured. In Pro O/B, the only limits were on displacement.
In Stock we all compared notes on how to best build a KG-4, MK 15, a 20 H etc. In Pro they said OK, we can only be X # cu.in's (CC's for you Jackie ;) ) or less but thats the rules so let us think....., humh........
The guy that dominated 500cc and set every record for yrs figured out how to take four 125cc, single cylinder MX jugs and graft them to a custom made four cylinder case and "created" a 500cc four cylinder, horizontally opposed monster.
It's different too if it's not a mfg trying to sell on Monday.

Formula One car racing used to be that class. It is turning into a green class.
Last year they ran naturally asperated 2.4 liter V-8's w/a 18K rev limit which was down from a previous 22K! Think about that valve train at 22 K!
If you allow the thinkers to think, they will.

I understand the cost aspect but these guys are way beyond that and most of us liked the class because we saw stuff that was Star Wars level technology. Beyond NASA.
A true gear head wants to see the baddest mammer jammers on the planet. Period and no excuses.
There are other classes for rules but give us one with none.

I think Mod U was close to that even though most of their records were equal to or bellow the Champ/F-1 records.
How do we know w/o trying?

One of my hero's, Smokey Yunick (research him Jackie, you'll like what you read) used to say if your motor was still running past the finish line, you didn't modify it enough ;)
The manufacturers own F1 now therefore they want to spend the money on technology they can use, small turbo and re gen is all about new cars

[lars strom]

Back on topic..!!!!!


OMC and the Rotary outboard took the overall win in Windermere 1973


http://svera.se/blogg/omc-and-the-rotary-outboard-took-the-overall-win-in-windermere-1973/


More from Galevston Classic 1973.

[lars strom]

Tom Posey checking the powerful Johnson rotary.

[lars strom]

A Rotary – (Wankel) wins the 2 liter class in Paris 6 hours 1970.


http://svera.se/blogg/a-rotary-wankel-wins-the-2-liter-class-in-paris-6-hours-1970/

[olboatman]

Lars It looks like the driver was throne out of # 28 with the OMC power on that lap ---- must have been a great ride! Gary:eek::thumbsup:

[lars strom]

Hee Hee Gary..I did not see that..you are right..the driver of boat #28 did go for the "dead fish" in the dirty river Seine..:)

A Rotary – (Wankel) wins the 2 liter class in Paris 6 hours 1970.


http://svera.se/blogg/a-rotary-wankel-wins-the-2-liter-class-in-paris-6-hours-1970/

[Rotary John]

here is the link again to the only known footage of the rotary running. It was filmed for a potato chip commercial at Lake Carol Ill.https://www.youtube.com/watch?v=k3sr-aSoDAA
Jackie; especially for you. Glad to see you are back home and returning to somewhat normal.

[jackiewilson]

336972
here is the link again to the only known footage of the rotary running. It was filmed for a potato chip commercial at Lake Carol Ill.https://www.youtube.com/watch?v=k3sr-aSoDAA
Jackie; especially for you. Glad to see you are back home and returning to somewhat normal.
hey Johnno, thanks for the ROTORY clip-------here's the twelve stack ROTORY Concept I did to impress you. Nobody liked it-----it's down in the shed.
Will definitely be in Tavares in the fall, expect to collect the bottle of malt then.

[Bob V]

336982

[jackiewilson]

336982

thanks for the ninety degree turnaround Bob

[Bob V]

thanks for the ninety degree turnaround Bob

My pleasure....better than everyone having a stiff neck...:eek:

[CNC_Guy]

here is the link again to the only known footage of the rotary running. It was filmed for a potato chip commercial at Lake Carol Ill.https://www.youtube.com/watch?v=k3sr-aSoDAA

Is that really what they sounded like?

[John Schubert]

Is that really what they sounded like?
NO! The sound was dubbed in.

[Ernie Brink]

The four strokes of a internal combustion occurs simultaneously in a wankel enginethis makes it more efficient than a piston engine this why its the future sometimes you have to look at something a long time before all of us see the the light wankels will spin on

[jackiewilson]

The four strokes of a internal combustion occurs simultaneously in a wankel enginethis makes it more efficient than a piston engine this why its the future sometimes you have to look at something a long time before all of us see the the light wankels will spin on

Yeah, yeah, yeah,-Ernie,---------and on and on and on and on and on, just like they've been doing for over a hundred years. Breaking engineers hearts and bankrupting companies. Just how much longer you want to look ?
Until they cure the basic flaws in the design, the damn thing will never ever work, let alone make one red cent profit.
I seem to have been down this particular road before-------Deja---Vous ?

[Capt.Insane-o]

370604

[FUJIMO]

http://www.screamandfly.com/attachment.php?attachmentid=370604&d=1490567811

[Rotary John]

http://www.screamandfly.com/attachment.php?attachmentid=370604&d=1490567811
The RC oil was 30wt Shell Rottela with 10% kerosene so it would pour at cold temps.

[Bob V]

usually any tunnel boat runs at its best when it's NEARLY free of the water, literally FLYING, but pointing straight


Literally Flying...​


370970

[Rotary John]

Literally Flying...​


370970

Jimbo; first lap Parker 1973.

[jackiewilson]

Jimbo; first lap Parker 1973.

wonder why that was the only picture ?

[Bob V]

wonder why that was the only picture ?

Perhaps it was running so fast that the photographers could not get it in focus before it was gone...:reddevil:

[Rotary John]

Here's some more for you Jackie:371120371120371121

[Rotary John]

371122

[Rotary John]

For those that have asked you can see in this picture the engine is mounted at the bottom of the bucket wich in turn is mounted directly yo the gearcase. No mid section403760

[Bob V]

403802

[techteam]

Hey John my friend looks like you were in Windermere after all...

405677

[techteam]

John I think these have never been seen. Windermere Grand Prix.

405678405679405680405681405682

[Rotary John]

James: Your correct, I haven't seen these before. Where did you find them? Look carefully at Sanders 20 and Downard 22 at the bucket. You will see Downards is shiney silver and Sanders is the Johnson gold. Someone at Brugge mounted an Evinrude engine on Downards boat. We just put a Johnson shroud on it and let it go. Which he and Posey won.

[jackiewilson]

Hey John my friend looks like you were in Windermere after all...

405677
schunky refuelling—— And Rick La Monte in the Merc Jacket.

[Rotary John]

Once again the rotary beat the merc V-6

[nitro_rat]

Once again the rotary beat the merc V-6

Surprise, surprise! A race only, nothing-even-remotely-close-ever-released-to-the-public, super duper top secret racing motor beats run-of-the-mill consumer outboard!!!

Just pickin’...

[FUJIMO]

Joking aside, I wonder what OMC had into the rotary outboard project, dollars wise? Any idea?

[Rotary John]

It's hard to factually say because much of the cost was absorbed by the production snowmobile engine and other rotary engine developments. If anyone could ever see the cost reporting for project D706, it might give some idea. My guess costs related to the race motor was in the 250/500K dollar range. That figure wouldn't include, boats, travel etc but only the engine. I was making $10,000/yr at the time and for '74 &'75 all of my time was charged to the rotary race engine. If my memory is any good, I recall OMC had 12/15 million total invested in the rotary engines programs for the initial signing in '66 till the end.

[Rotary John]

Surprise, surprise! A race only, nothing-even-remotely-close-ever-released-to-the-public, super duper top secret racing motor beats run-of-the-mill consumer outboard!!!

Just pickin’...

Not available to the public, fuel injected V-6, so secret the inspectors had to go under the covers to inspect the kill switch.
The rotary was widely available for public viewing; a parts board was with all the rotary parts was shown in publications; engines were shown at major trade/boat shows around the world. Boating editors were allowed to actually drive the race boat, take pictures and publish stories.In addition the rotary snowmobile engine (which was the bases for the race motor) was on the market in '72.Now which motor was top secret?
Factually, the only real secrets of the race motor, was the crankshaft joining, the exhaust manifold and the cooling. The remainder of the parts came directly from the snowmobile engine with minor modifications.

[powerabout]

It's hard to factually say because much of the cost was absorbed by the production snowmobile engine and other rotary engine developments. If anyone could ever see the cost reporting for project D706, it might give some idea. My guess costs related to the race motor was in the 250/500K dollar range. That figure wouldn't include, boats, travel etc but only the engine. I was making $10,000/yr at the time and for '74 &'75 all of my time was charged to the rotary race engine. If my memory is any good, I recall OMC had 12/15 million total invested in the rotary engines programs for the initial signing in '66 till the end.
When did all rotary stuff stop?

[nitro_rat]

I guess I wasn’t aware of the snowmobile engines, we don’t have those in Texas!

[Rotary John]

When did all rotary stuff stop? The rotaries ran for the last time in the spring of '75. That was pretty much the end of the rotary program at OMC. Most of the guys quit that year and I left the following summer. OMC research in Milwaukee played around with rotaries for awhile after that, but nothing came of it.

[powerabout]

The rotaries ran for the last time in the spring of '75. That was pretty much the end of the rotary program at OMC. Most of the guys quit that year and I left the following summer. OMC research in Milwaukee played around with rotaries for awhile after that, but nothing came of it.
was 75 also the last snowmobile with them in it?

[Rotary John]

"74. OMC went out of the SM business in '74.

[Rotary John]

Complements of my friend Jackie Wilson405726

[techteam]

Hi John

Ann's Dad died last year and there is so much stuff to go through. He took them at the event. I'm hoping that there is some film as well. It's going to take ages to go through it all and I don't have the time at the moment.

[WaterZebra]

Not available to the public, fuel injected V-6, so secret the inspectors had to go under the covers to inspect the kill switch.
The rotary was widely available for public viewing; a parts board was with all the rotary parts was shown in publications; engines were shown at major trade/boat shows around the world. Boating editors were allowed to actually drive the race boat, take pictures and publish stories.In addition the rotary snowmobile engine (which was the bases for the race motor) was on the market in '72.Now which motor was top secret?
Factually, the only real secrets of the race motor, was the crankshaft joining, the exhaust manifold and the cooling. The remainder of the parts came directly from the snowmobile engine with minor modifications.


Rotary John - too bad we didn't have the internet and social media back in the early 70's. Maybe marketing / race decisions by both Merc and OMC would have been radically different? I was a kid in high school in 73 and didn't even have a clue about the OMC rotary and V6 development programs until I saw photos and brief write-ups in the OMC sales brochures. You can add local dealerships to "clueless" list too. Never showed any interest in R&D unless it meant a few more fishing motors sold out the door. I lived on the west coast at the time and had I known about the rotaries running in Provo UT, I would have driven there just to see them run. I just saw the current company summary for Merc on Google.............Anything 30HP and under - Tahatsu in Japan............Midsize 40-60HP somewhere else (Oklahoma?) and the big stuff V6 / Verado, etc still in FondDuLac

[Rotary John]

[QUOTE=techteam;3038630]Hey John my friend looks like you were in Windermere after all...

405677
It Ain't me, but it sure does look like a young me. I think that is a Merc Tech fueling the T-3, and it may be Garbrect with his back to the cmara.

[Ozzman]

Click on Link Below for short Video of the Rotary Public Launch from 1973
490290 490291

490303


https://www.britishpathe.com/video/VLVA40Z6WDRXSRHXFHWTG5GQTCI2N-USA-FIRST-ROTARY-ENGINE-FOR-OUTBOARD-SPEEDBOAT-USE-SUCCESSFULLY/query/speedboat

[Mark75H]

Now we know the sound

[WaterZebra]

Now we know the sound

Sound? I've listened to every rotary clip posted on this site and they all sound like dubbed in stock outboards. Whoever made this clip should have turned down Bill Muncie's voice so we could listen to the thing run! Only person who can authenticate the rotary's sound on this website is RJ! Real rotary sound? Doubt it. All the comments about the rotary's sound have had one thing in common..........it sounded like no other outboard power made. One way to settle the argument is to get one of these stingy collectors who still has one to have RJ look at it and dry fire it............ even for just a moment.

[2us70]

I was puzzled by the sound in that clip also. Many years ago there was a racing airplane built with 2 Mazda rotaries in it. I heard it run several times and it didn't sound like that. The airport got noise complaints every time they flew that thing. We would then go out to the runway and watch it land because the rear engine would overheat. The overheating was not the motors fault but a design problem with the aircraft.

[Rotary John]

Sound? I've listened to every rotary clip posted on this site and they all sound like dubbed in stock outboards. Whoever made this clip should have turned down Bill Muncie's voice so we could listen to the thing run! Only person who can authenticate the rotary's sound on this website is RJ! Real rotary sound? Doubt it. All the comments about the rotary's sound have had one thing in common..........it sounded like no other outboard power made. One way to settle the argument is to get one of these stingy collectors who still has one to have RJ look at it and dry fire it............ even for just a moment.
It sounds more like the V-6 than the rotary; but not sure. Notice when Munice is talking there in no engine sound, which leads me to thing the sound is dubbed in.
Bob Zips in Conn. has 2 (of 4) of the latest rotaries. I have talked and e-mailed him about letting one run for history sake, but never heard back from him. BRP has the other 2 and when I asked for 1 when they stopped producing outboards, I was told the were going to their museum in Canada. The one Seaway has is an older unit and I don't know if it is run-able or not. Hey guys, I'm 76 and if something like that is going to happen, it better be soon. As long as I'm able I will do it in a heart beat.

[lars strom]

@Rotary John (https://www.screamandfly.com/member.php?u=48164)

Same here..I am not 100% sure that the outboard sound in the video is from the Rotary racing engine.
Paris 6 hours 1974 is a long time ago when I raced with the two Rotary powered boats. (in my own OE class boat)..

[Rotary John]

This one is for Mouse's daughter if she doesn't already have it. I think is see a very young Johnny Sanders on the left also. S, Africa 1973490487

[Rotary John]

This is the engine Seaway has. it looks from the picture to be complete. I don't know about the carbs as we never painted the carbs black; but they appear to have both the fuel and primer rails. It has the 15/17 gearcase, but again I don't know if anything is inside. All the internal parts were V-4 except the input shaft. I would be happy to try to get it to run if somebody covers my expenses.490488

[WaterZebra]

It sounds more like the V-6 than the rotary; but not sure. Notice when Munice is talking there in no engine sound, which leads me to thing the sound is dubbed in.
Bob Zips in Conn. has 2 (of 4) of the latest rotaries. I have talked and e-mailed him about letting one run for history sake, but never heard back from him. BRP has the other 2 and when I asked for 1 when they stopped producing outboards, I was told the were going to their museum in Canada. The one Seaway has is an older unit and I don't know if it is run-able or not. Hey guys, I'm 76 and if something like that is going to happen, it better be soon. As long as I'm able I will do it in a heart beat.

2+2+1 = 5 The rotary was one of the greatest R&D programs OMC ever had. Production program? No! OMC's V6 and V8 projects were legit product development production programs.

[Rotary John]

2+2+1 = 5 The rotary was one of the greatest R&D programs OMC ever had. Production program? No! OMC's V6 and V8 projects were legit product development production programs.
You forgot that OMC produce over 15,000 rotary snowmobiles in 1972 & 73; many of which are still running today.

[Rotary John]

It sounds more like the V-6 than the rotary; but not sure. Notice when Munice is talking there in no engine sound, which leads me to thing the sound is dubbed in.
Bob Zips in Conn. has 2 (of 4) of the latest rotaries. I have talked and e-mailed him about letting one run for history sake, but never heard back from him. BRP has the other 2 and when I asked for 1 when they stopped producing outboards, I was told the were going to their museum in Canada. The one Seaway has is an older unit and I don't know if it is run-able or not. Hey guys, I'm 76 and if something like that is going to happen, it better be soon. As long as I'm able I will do it in a heart beat.
The sound as Jimbo goes by sounds like WOT at full speed, but you will notice the boat is Porpoiseing meaning he is running part throttle at reduced speed.

[Rotary John]

2+2+1 = 5 The rotary was one of the greatest R&D programs OMC ever had. Production program? No! OMC's V6 and V8 projects were legit product development production programs.
In some ways I would agree with you. While the rotary program was indeed a very active production development program with 6, 50 & 100HP units designed and running, the 4 rotor program was Charlie Strang's way of kicking Charlie Alexander's ass. You noticed as soon as he had a V-6 to race the 4 rotor race engine stopped even though the rotary had more HP. The rotary out preformed the V-6 Windemere. Paris and St. Louis
It is my opinion the rotary program was stopped because it had 10x less hydrocarbon emissions than the equivalent 2-stroke.. OMC at the time was selling all the 2-strokes they could produce and with out a complete rotary line up couldn't risk EPA banning 2-stroke outboard like Calf. did in 1974 to motorcycles.

[WaterZebra]

You forgot that OMC produce over 15,000 rotary snowmobiles in 1972 & 73; many of which are still running today.

We are talking marine outboard power, not snowmobiles.

[Rotary John]

We are talking marine outboard power, not snowmobiles.
When was the first OMC 2l cross V-6 raced and when was it's first production?

[Ozzman]

Some of these may be on Boat Racing Facts

Copied from (https://www.carthrottle.com/post/wbyo24x/)
490526 490527

Images below off YouTube stills

490528 490529 490530 490531 490532

[Rotary John]

As a point of interest; all these pictures came from my originals. I sent them to Ken along with the "***the real facts" original script. They have been floating around the internet for years. I still have the originals.

[techteam]

I don't believe Pathe would overdub the sound as it was predominately a news channel. However the timing might not quite be correct so Johns comments may be the answer, right sound wrong place.

[Rotary John]

Mike Gwaltney: Who is the fellow opposite Ted Wright in the first picture. I don't remember. Tom Corton?

[Ozzman]

As a point of interest; all these pictures came from my originals. I sent them to Ken along with the "***the real facts" original script. They have been floating around the internet for years. I still have the originals.
Hi John, thanks for you reply.
I hadn't posted for some time and posted on recently.again.
Apologies if I repost your work/pics :D . You know nobody counterfeits a $40 bill, only the real stuff :thumbsup:
I'll message you a link related to these pics below you can share if you want.
490536 490537 490538

[SCT]

John, I’m sure this information is in the last 28 pages but how many rotary race engines were built? And what was the dressed weight?

Great thread,

Thx-

[Rotary John]

Your right, it's been posted many times. The engines were rebuilt after every outing. It was Charlie Strang's motto; race it, break it, rebuild it, race it again. In addition, we were making changes, upgrade, additional HP continually. There were only 6 black exhaust manifold ever made, so the most at any one time would have been 6. Most of the time we had 4 ready to race with 1 spare powerhead. My memory is shot, but I recall a running powerhead weighed 197 # and a complete assembly was 250/275 #.

[Instigator]

Those pics are from the mechanics illustrated story on the rotary.

I still have that magazine.




Hi John, thanks for you reply.
I hadn't posted for some time and posted on recently.again.
Apologies if I repost your work/pics :D . You know nobody counterfeits a $40 bill, only the real stuff :thumbsup:
I'll message you a link related to these pics below you can share if you want.
490536 490537 490538

[Ozzman]

Posting for a friend :p
490564
Let me know Rotary John/Ken/Lars etc if you don't have it. Happy to share the whole article if nobody has it :thumbsup:

[Ozzman]

You got any of these?
490565 490566
Got these too these if anyone hasn't got them :D

[WaterZebra]

Your right, it's been posted many times. The engines were rebuilt after every outing. It was Charlie Strang's motto; race it, break it, rebuild it, race it again. In addition, we were making changes, upgrade, additional HP continually. There were only 6 black exhaust manifold ever made, so the most at any one time would have been 6. Most of the time we had 4 ready to race with 1 spare powerhead. My memory is shot, but I recall a running powerhead weighed 197 # and a complete assembly was 250/275 #.

I have a feeling the remaining rotaries will never run again (test tank or boat). They will take their place beside the P-38 Lightning. Too valuable to run or fly.

[Rotary John]

I have a feeling the remaining rotaries will never run again (test tank or boat). They will take their place beside the P-38 Lightning. Too valuable to run or fly.
Unfortunately I think you are correct. The 2 Bob Zips has he guards with his life as if the came from King Tuts tomb. He has told me he was going to give them to some museum when he passes. Besides, only 1 has a gear case. The 2 or 3 BRP has, they have no interest in running and have supposedly sent them to their museum in Quebec to sit next to their locomotive. I don't know if Seaway's machine is complete or runnable. I remember someone saying way back that this was the unit on display downstairs of Waukegan Engineering and it was locked up. Without looking at the motor, I can only speculate what might be wrong and what it would take to fix it.

[powerabout]

Unfortunately I think you are correct. The 2 Bob Zips has he guards with his life as if the came from King Tuts tomb. He has told me he was going to give them to some museum when he passes. Besides, only 1 has a gear case. The 2 or 3 BRP has, they have no interest in running and have supposedly sent them to their museum in Quebec to sit next to their locomotive. I don't know if Seaway's machine is complete or runnable. I remember someone saying way back that this was the unit on display downstairs of Waukegan Engineering and it was locked up. Without looking at the motor, I can only speculate what might be wrong and what it would take to fix it.
Knowing Greg he will try to get the parts and run it.

[Rotary John]

Knowing Greg he will try to get the parts and run it.
I know where to get the parts. It's knowing what parts are needed and how to put it back together once you have taken it apart.

[WaterZebra]

Knowing Greg he will try to get the parts and run it.

I dunno..........he has the OMC V8 speed record motor and hydro and a vintage V8 Molinari and I have never heard any news about those running?

[powerabout]

I dunno..........he has the OMC V8 speed record motor and hydro and a vintage V8 Molinari and I have never heard any news about those running?

pretty sure he doesnt have the engine from that record setting hydro or any other for it?
He does have a dyno now though.

[Rotary John]

This is the first lap of Parker '73. Note the boat is completely out of the water and the motor is tucked under as far as it goes. Jimbo driving 1 handed, waving to the Merc pits. One of the best rotary pictures.490630

[lars strom]

@Rotary John (https://www.screamandfly.com/member.php?u=48164)
Yes, its a great picture. I think Jimbo is also waving at Jackie Wilson..:):iagree:
PS. This ScottiCraft does not have a full deck tunnel.
You can clearly see that.


https://www.screamandfly.com/attachment.php?attachmentid=490630&d=1626716032

[Rotary John]

Lars: At Parker, 490638Jimbo's boat had slots in the front. You can get a good view of the slot at the very beginning of the Miami video. Posey's boat was a full front. The boat we used for testing in Fl. was Jimbo's black & white Scotti that was a full front. If I remember Jimbo said it was narrow, not as wide as other Scotti's. Rick McKinley blew it over and destroyed it latter on. This was Posey's boat for parker. The pickle fork boats didn't come till '74 Paris. You posted Posey's Paris boat and this is Wood's Paris Boat-both pickle490639 forks.

[Rotary John]

Outboard Marine Corporation 4 Rotor: The Real Story - YouTube (https://www.youtube.com/watch?v=SeomAj6QhvA)
A video about the OMC rotaries

[powerabout]

Outboard Marine Corporation 4 Rotor: The Real Story - YouTube (https://www.youtube.com/watch?v=SeomAj6QhvA)
A video about the OMC rotaries

Hi John
Whats the issue with horizontal crank and oil lubed versus vertical and fuel oil lubricated?

[Rotary John]

Hi John
What's the issue with horizontal crank and oil lubed versus vertical and fuel oil lubricated?
There are 2 basic types of rotary engines. Oil cooled rotor and charge cooled rotor. In the oil cooled type, oil is circulated inside the rotor to cool it. With a pressurized oil system, the engine can use Babbit bearings like most automotive engines. Oil cooling requires oil seal to prevent the oil from escaping into the combust chamber and burned. It also requires an oil pump and cooler to reject the heat gathered from the rotor cooling. All of this adds to the weight, increased friction Hp., cost and complexity. The upside is the intake charge can be inducted directly into the chamber resulting in very high volumetric efficiency. The orientation of the crank has no bearing on the engine other than for oil return. Most of the automotive rotary engines are oil cooled, aka Mazda.
The charged cool rotor uses the intake charge to pass thru to rotor to cool it. This eliminates the requirement for oil seals, the oil pump and cooler and the sump. Because of no pressurized oil system Babbit bearings can not be used and roller and/or ball bearings are required to support the rotor and crankshaft. The upside is a much simpler and less costly engine. The down side is a significant reduction in volume metric efficiency due to the torturous path the charge must take to get to the intake chamber and the heating of the charge as it cools the rotor. In addition oil must be mixed with the gas to lubricate the bearings. Once again the crank orientation makes no difference.
Thus for outboard use the weight, cost and simplicity makes the charged cool rotor the best choice.
Hope this make sense.

[Rotary John]

As a side note to the above about oil cooled engines. OMC actually started it's development work with the oil cooled rotor type. We had a 100 CID 2 rotor running as both an outboard and a stern drive producing in excess of 200 HP. The cost of the outboard version was significantly higher that the current 2 strokes. The I/O version competed with the cost of the automotive engines currently being used. In addition the 200 HP engine allowed the dog house to be removed and a full width rear seat with the engine under it. Because of the weight reduction it would out perform a V-8 in all be top end speed. Because the volumes of the I/O could not justify the tooling and the outboard version was too expensive, the oil cooled program was dropped.

[powerabout]

There are 2 basic types of rotary engines. Oil cooled rotor and charge cooled rotor. In the oil cooled type, oil is circulated inside the rotor to cool it. With a pressurized oil system, the engine can use Babbit bearings like most automotive engines. Oil cooling requires oil seal to prevent the oil from escaping into the combust chamber and burned. It also requires an oil pump and cooler to reject the heat gathered from the rotor cooling. All of this adds to the weight, increased friction Hp., cost and complexity. The upside is the intake charge can be inducted directly into the chamber resulting in very high volumetric efficiency. The orientation of the crank has no bearing on the engine other than for oil return. Most of the automotive rotary engines are oil oiled aka Mazda.
The charged cool rotor uses the intake charge to pass thru to rotor to cool it. This eliminates the requirement for oil seals, the oil pump and cooler and the sump. Because of no pressurized oil system Babbit bearings can not be used and roller and/or ball bearings are required to support the rotor and crankshaft. The upside is a much simpler and less costly engine. The down side is a significant reduction in volume metric efficiency due to the torturous path the charge must take to get to the intake chamber and the heating of the charge as it cools the rotor. In addition oil must be mixed with the gas to lubricate the bearings. Once again the crank orientation makes no difference.
Thus for outboard use the weight, cost and simplicity makes the charged cool rotor the best choice.
Hope this make sense.
Thanks John


These days lighter engine means an OMC V8 is normal weight, perhaps today a boosted oil cooled rotary would fit right in?

[WaterZebra]

There are 2 basic types of rotary engines. Oil cooled rotor and charge cooled rotor. In the oil cooled type, oil is circulated inside the rotor to cool it. With a pressurized oil system, the engine can use Babbit bearings like most automotive engines. Oil cooling requires oil seal to prevent the oil from escaping into the combust chamber and burned. It also requires an oil pump and cooler to reject the heat gathered from the rotor cooling. All of this adds to the weight, increased friction Hp., cost and complexity. The upside is the intake charge can be inducted directly into the chamber resulting in very high volumetric efficiency. The orientation of the crank has no bearing on the engine other than for oil return. Most of the automotive rotary engines are oil oiled aka Mazda.
The charged cool rotor uses the intake charge to pass thru to rotor to cool it. This eliminates the requirement for oil seals, the oil pump and cooler and the sump. Because of no pressurized oil system Babbit bearings can not be used and roller and/or ball bearings are required to support the rotor and crankshaft. The upside is a much simpler and less costly engine. The down side is a significant reduction in volume metric efficiency due to the torturous path the charge must take to get to the intake chamber and the heating of the charge as it cools the rotor. In addition oil must be mixed with the gas to lubricate the bearings. Once again the crank orientation makes no difference.
Thus for outboard use the weight, cost and simplicity makes the charged cool rotor the best choice.
Hope this make sense.

RJ - You should write a bio book on the OMC Rotary.

[Instigator]

Have you seen this John?

Looks/sounds very impressive.

Have heard of similar before but don’t think any have made it through prototype stages.

The good is, the man behind the design has the background and knowledge.


https://www.cycleworld.com/story/motorcycle-news/crighton-cr700w-track-bike-unveiled/

[Rotary John]

Have you seen this John?

Looks/sounds very impressive.

Have heard of similar before but don’t think any have made it through prototype stages.

The good is, the man behind the design has the background and knowledge.


https://www.cycleworld.com/story/motorcycle-news/crighton-cr700w-track-bike-unveiled/
Yes I have heard of it before. The engine company has been making rotaries for many years; primarily drone engines. I suspect the bike will be a flash in the pan (cost) and if it dominates will be banned. I seem to recall a similar situation.

[Rotary John]

Thanks John


These days lighter engine means an OMC V8 is normal weight, perhaps today a boosted oil cooled rotary would fit right in?
If I remember the 3.5 L V-8 weighed around 235# and produced 450HP. The rotary powerhead was just over 2 L, weighed around 130 # and produced around 300 HP. Knowing what I know today and with todays materials, I believe the same rotary could produce 450 HP weighing less than 100#. Problem is no one today is interested in boat racing to invest the monies required.

[Instigator]

The designer ran Norton Motorcycles successful, multi race winning rotary bike program.
Norton went belly up and new owners finished driving them in the dirt.

One of my classic bike mags had a great, in-depth, multi page story on the new bike/motor.

It is cooled through the crank and he made the rotors wider instead of larger diameter like Mazda did.
He thought that was a mistake on their part.

He is getting 220 hp+ from 700 CC’s.

Agreed on seeing how deep new owners pockets are.


Yes I have heard of it before. The engine company has been making rotaries for many years; primarily drone engines. I suspect the bike will be a flash in the pan (cost) and if it dominates will be banned. I seem to recall a similar situation.

[Rotary John]

Mazda made the rotors narrower because of emissions. With a W/E ratio of around 4; (rotor width/eccentric value) is the most efficient to reduce the surface to volume ratio; ie. Hydrocarbon emissions. In addition, Mazda used side ports and the intake area in not dependent on rotor width. Thus a narrower rotor gave proportionately more intake are per displacement.
Norton uses a peripheral port directly into the rotor hsg. and making them wider allows a larger intake port (more intake area) w/o changing port timing. They weren't worried about emissions on a race bike.

[powerabout]

Mazda made the rotors narrower because of emissions. With a W/E ratio of around 4; (rotor width/eccentric value) is the most efficient to reduce the surface to volume ratio; ie. Hydrocarbon emissions. In addition, Mazda used side ports and the intake area in not dependent on rotor width. Thus a narrower rotor gave proportionately more intake are per displacement.
Norton uses a peripheral port directly into the rotor hsg. and making them wider allows a larger intake port (more intake area) w/o changing port timing. They weren't worried about emissions on a race bike.
Would dfi on a rotary make a big improvement in emissions to try to get the fuel away from all that surface area?

[Rotary John]

Direct injection has been tried and helps some on the intake side, but you still have the fuel quench problem on the combustion side. At some point, alternatives to the rotary due to the cost to achieve emission results are more economical. I believe the future of the rotary is as a range extender in electric vehicles, size, weight, lack of vibration. The engine could be optimized to run at a specific RPM driving a generator or specialized uses where power to weight/size are critical.

[Mark75H]

John, as always, thank you for the education on this subject.

[powerabout]

Direct injection has been tried and helps some on the intake side, but you still have the fuel quench problem on the combustion side. At some point, alternatives to the rotary due to the cost to achieve emission results are more economical. I believe the future of the rotary is as a range extender in electric vehicles, size, weight, lack of vibration. The engine could be optimized to run at a specific RPM driving a generator or specialized uses where power to weight/size are critical.

so what we need is a ceramic rotor so it becomes an adiabatic engine, no heat loss?

[Bob V]

John, as always, thank you for the education on this subject.

:iagree:

[Lake X Kid]

If I remember the 3.5 L V-8 weighed around 235# and produced 450HP. The rotary powerhead was just over 2 L, weighed around 130 # and produced around 300 HP. Knowing what I know today and with todays materials, I believe the same rotary could produce 450 HP weighing less than 100#. Problem is no one today is interested in boat racing to invest the monies required.

How do you quantify cubic-inches/liters for a Rotary engine?

A) One rotor has 3 combustion surfaces/heads. Therefore, (per each rotor) 3 x combustion chamber area = cubic-inches/liters.

B) One rotor/combustion chamber. Therefore, each rotor is only designated as only having 1 combustion head. 1 x combustion chamber area = cubic-inches/liters.

I am wrong to think the rotor engine should be classified as example A. Giving the rotor engine & the conventional combustion piston engine equal footing in engine size comparison.

Example B, seems to me, to give the rotary engine an unfair advantage in racing classification against piston engines.


https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fcarbiketech.com%2Fwp-content%2Fuploads%2F2019%2F12%2FRotary-Engine-02.jpg&f=1&nofb=1


https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fwww.dktireservice.com%2Fwp-content%2Fuploads%2F2015%2F11%2FScreenshot-297.png&f=1&nofb=1

[Instigator]

Agreed.

I followed IMSA car road racing in the ‘80’s and Mazda ruled GTU which is Grand Touring Under 3.0 liters.

Many competitors complained that Mazda was given an unfair, +50% displacement capacity due to the unfair way a rotary was classified.

Love the motors and tech but please…..




How do you quantify cubic-inches/liters for a Rotary engine?

A) One rotor has 3 combustion surfaces/heads. Therefore, (per each rotor) 3 x combustion chamber area = cubic-inches/liters.

B) One rotor/combustion chamber. Therefore, each rotor is only designated as only having 1 combustion head. 1 x combustion chamber area = cubic-inches/liters.

I am wrong to think the rotor engine should be classified as example A. Giving the rotor engine & the conventional combustion piston engine equal footing in engine size comparison.

Example B, seems to me, to give the rotary engine an unfair advantage in racing classification against piston engines.


https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fcarbiketech.com%2Fwp-content%2Fuploads%2F2019%2F12%2FRotary-Engine-02.jpg&f=1&nofb=1


https://external-content.duckduckgo.com/iu/?u=https%3A%2F%2Fwww.dktireservice.com%2Fwp-content%2Fuploads%2F2015%2F11%2FScreenshot-297.png&f=1&nofb=1

[Rotary John]

At the time of the rotary race engine, they were competing against 2 strokes. A 2 stroke engine has one power pulse per crankshaft revolution; so does a rotary. A 2 stroke completes all phases, intake, compression, power and exhaust for each revolution of the crankshaft; so does a rotary. Thus if compared to a 2 stroke the displace should be measured for 1 revolution of the crank. It's the 4 stroke that's the oddball. It takes 2 complete revolution of the crank to complete all 4 phases. I don't recall anyone ever saying a 2 stroke should be measured for 2 crank revolutions as a 4 stroke. A 4 stroke displacement has always been measured displaced volume per crank revolution, same as a 2 stroke and a rotary. The argument only comes up when the rotary dominates. Kinda like Andy Granitily's turbine. Kinda like when the big boys banned the 2 stroke in thunder boat racing. The establishment hates being beat. Enough for tonight, I'm going to the shower and bed.

[2us70]

I count 3 ignition events per crank revolution. One for each rotor face. Thus the total swept volume of all 3 faces equals displacement. Seems like basic trig to me?

[Rotary John]

I count 3 ignition events per crank revolution. One for each rotor face. Thus the total swept volume of all 3 faces equals displacement. Seems like basic trig to me?
You don't count too well. The rotor turns at 1/3 the speed of the crank. There is ONLY ONE spark plug fire for each rotation of the crank.
Wankel animation - YouTube (https://www.youtube.com/watch?v=K6oQqN0fpk8)

[techteam]

I count 3 ignition events per crank revolution. One for each rotor face. Thus the total swept volume of all 3 faces equals displacement. Seems like basic trig to me?

Remind me not to ask you to balance my cheque book.

[techteam]

Next thing John somebody will mention the usual.

Ha, looks like you beat me to the punch. I'm getting slow.

[Lake X Kid]

The rotor turns at 1/3 the speed of the crank. There is ONLY ONE spark plug fire for each rotation of the crank.
Wankel animation - YouTube (https://www.youtube.com/watch?v=K6oQqN0fpk8)

That clarifies a lot, thanks RJ.

[Rotary John]

The real difference in the rotary is each of the 4 cycles consumes approx 270 degrees of crank rotation. A 2 stroke by contrast consumes approx. 90 degrees for each cycle and a 4 stroke approx 180 degrees. ( forget about overlap and exact port timing). This is the reason the rotary has such high power density. Displace ment is measured max volume - min. volume x the number of cylinders or rotors. I you want equality give a fixed amount of fuel and run what you brung. Audi did that with their turbo diesels.

[Rotary John]

Next thing John somebody will mention the usual.

Ha, looks like you beat me to the punch. I'm getting slow.
James: I'm surprised Jackie hasn't jumped in and claim it should be 8 times because he raced a V-8 four stroke.

[Instigator]

Not that I matter in this equation but…, I still don’t get it John.

4 stroke to two, I do.

Rotary to everything else, I still don’t.

One crankshaft revolution what do we have correct?

[Rotary John]

Not that I matter in this equation but…, I still don’t get it John.

4 stroke to two, I do.

Rotary to everything else, I still don’t.

One crankshaft revolution what do we have correct?
One crankshaft revolution: One spark plug fire, one power stroke. one intake, one compression, one exhaust; just like a 2 stroke. The difference is these events happed simultaneously in a rotary, while they happen sequentially in a 2 stroke. You have to also remember the rotary is a 4 cycle. It has a positive exhaust cycle where a 2 stroke exhaust is dependent on blow down and the incoming fresh charge to force the spent charge out the exhaust port. Same is true for the rotary intake, compression and power cycles.

[powerabout]

I think were the punters get confused is which part is counted as a revolution?
See above for crank as explained by John.

[2us70]

So the crankshaft in overdriven 3 to 1 from the rotor? Does this have an effect on torque at the crankshaft output end? Also what are the revs seen by both the rotor and crank in operation? My only experience with a rotary was driving my brother-inlaw's Mazda RX-3 many years ago.

[Rotary John]

You have said it correctly but should read the rotor turns at 1/3 crank RPM. The torque on the crank is determined by the eccentric of the shaft and the combustion pressure on the rotor and is independent of the rotor RPM. However, because the shaft has to turn approx. 270 Degrees before the exhaust port opens, the force on the eccentric lasts longer than a piston engine. Hope this makes sense.
The OMC race engine ran between 7000/8000 RPM crankshaft meaning the rotor turned 1/3 of that; 2333/2667 RPM. Before someone asks again, the final version of the race engine produced between 265/280 prop shaft HP at those RPM's. (1974)

[Lake X Kid]

The rotor engine’s rotational components seem to be more conducive to generating crankshaft rotation, then the action of converting piston’s linear motion into crankshaft rotation. High RPMs would seem not to be a major obstacle (in spite of an eccentric non-circular rotor motion, and the rotor’s larger circumference turning the smaller diameter crankshaft should supply ample torque.

However, being the rotor engine has a more favorable geometry of internal moving parts, why does it not dominate the boat & car market? Is the rotor engine’s weak link(s) due to … cooling issues, seal problems, combustion efficiency – in comparison to piston engines, or …?

[Rotary John]

In this day of electrification, I don't see anyone investing the capital required to produce a rotary economically. The world has been machining round holes and cylinders for 120 years and have become quite proficient at it. Mazda held on as long as they could, until emission abatement cost more than a competitive 4-stroke.
With today's materials, durability is not an issue. The rotary's weakness is its surface to volume ratio, resulting in significant flame quench, causing high hydro carbons and reduced fuel efficiency.
I believe if OMC would have continued the rotary in specific application, they may still be in business. I believe the rotary would have been competitive over the complexity, size and cost of the Ficht and their latest air injection system.
Imagine a 250HP twin rotary IO w/o a dog house. or a side wider 4 rotor 500HP IO also w/o a dog house. Both with 1/2 the weight of a comparable 4-stroke.

[Instigator]

Soooooooooo, does it fire every time a rotor lobe passes through a chamber??

As in, 3 lobes so it fires 3 times per rotor revolution?

[Rotary John]

Yes, however , the crank has made 3 revolutions for that to happen. Its's like a 2-stroke that way. If the crank revolves 3 times, the spark plug fires 3 times Thus by your way of thinking a 2-stroke should be measured X 3. The simplest way to measure displacement for ANY engine is to measure the displaced volume per each crankshaft revolution.

[Instigator]

No argument from me.
I am just trying to wrap my head around, how it does what it does.

Not throwing stones.

I spent 3 days trying to make sense of the illustrations posted ��

I thought I understood rotaries.
Clearly I did not.

I guess the argument could be, swept volume Vs crankshaft rotation?

I like it.

Is the rotary design being used anywhere besides the bike project I posted?

I caught your comments on emissions and the bike guys are using a total loss oil system and stated that it burns so clean it doesn’t show up in the exhaust.

I still have the ‘1973 Mechanix Illustrated issue on the OMC motor and remember what caught me the most was the engineering that allowed them to stack them up and make what ever power they wanted.

Always thought was brilliant and should be a game changer.



Yes, however , the crank has made 3 revolutions for that to happen. Its's like a 2-stroke that way. If the crank revolves 3 times, the spark plug fires 3 times Thus by your way of thinking a 2-stroke should be measured X 3. The simplest way to measure displacement for ANY engine is to measure the displaced volume per each crankshaft revolution.

[Rotary John]

There are a couple of company's in England making rotaries for drones and military activities. Mazda claims they will make a rotary range extender for their hybrid cars. Moller in California has put rotaries in all sorts of things and continues to look for investors to bring the engine to mass production. I have done consulting work for several company's building gen sets for the military, but none to my knowledge have gone into production.

[Instigator]

Yrs back, I tried to find a twin turbo RX-7, but failed.

Cant remember if it was that or the 8 where they got sued over inflated HP claims.

Claimed 280 but was closer to 250/260???

Id still like to have a twin turbo 7.

We have a shop, still in Cols that has specialized in Mazda rotaries from day 1.
Just passed it the other day and they had 20+ cars sitting in front.

BTW, re-read the first 14 pages of this thread last night!
13 yrs later, it still entrtains!

Sad part is Liquid Nirvanas absence.
I spoke w/him on the phone several times back in that era.
Sent him some OMC racing posters.

I remember he was devastated when the photo hosting service he was using,locked/erased all his, hundreds of photos and yrs of work.

I remember him telling me he was just doing it for the love of the brand.

[2us70]

Horse power being defined as "work over time " the rotary's long combustion pressure events seems to be it's big advantage. It also doesn't have the negative inertia problem of a reciprocating engine.

[Rotary John]

Yrs back, I tried to find a twin turbo RX-7, but failed.

Cant remember if it was that or the 8 where they got sued over inflated HP claims.

Claimed 280 but was closer to 250/260???

Id still like to have a twin turbo 7.

We have a shop, still in Cols that has specialized in Mazda rotaries from day 1.
Just passed it the other day and they had 20+ cars sitting in front.

BTW, re-read the first 14 pages of this thread last night!
13 yrs later, it still entrtains!

Sad part is Liquid Nirvanas absence.
I spoke w/him on the phone several times back in that era.
Sent him some OMC racing posters.

I remember he was devastated when the photo hosting service he was using,locked/erased all his, hundreds of photos and yrs of work.

I remember him telling me he was just doing it for the love of the brand.
here ya go.
Used Mazda RX-7 Turbo for Sale: 7 Cars from $26,500 - iSeeCars.com (https://www.iseecars.com/used_cars-t24726-used-mazda-rx-7-turbo-for-sale#id=100548112269)

[Instigator]

When I was looking at them, they were $10K cars!

I currently have a 600HP ‘2002 Trans Am and a 87hp MGB.

Some day I’ll own an RX-7, but not today.





here ya go.
Used Mazda RX-7 Turbo for Sale: 7 Cars from $26,500 - iSeeCars.com (https://www.iseecars.com/used_cars-t24726-used-mazda-rx-7-turbo-for-sale#id=100548112269)

[Lake X Kid]

... The rotary's weakness is its surface to volume ratio, resulting in significant flame quench, causing high hydro carbons and reduced fuel efficiency.



Would redesigning the Rotor's surface change the flame quench problem.

Like a concave rotor (see my poor illustration attempt to draw on the computer).

502597

[Rotary John]

Would redesigning the Rotor's surface change the flame quench problem.

Like a concave rotor (see my poor illustration attempt to draw on the computer).



502597
We all know a curved line between 2 points is longer than a straight line. Your concept just increased surface area for flame quench. The out side shape of the rotor is a mathematical shape based on the mathematical shape of the trochoid. go back to my you tube model and watch the rotor go around.

[lars strom]

NEW - Titanium Rotary Engine Key-chain Spinning Rotor Stimulates Motor |
On SALE

https://www.screamandfly.com/attachment.php?attachmentid=503923&d=1650370390

[seahorse]

NEW - Titanium Rotary Engine Key-chain Spinning Rotor Stimulates Motor |
On SALE



I bought one too.

[Lake X Kid]

I think my formulaic parameter puts the 2 Cycle's performance greater, than the 4 Stroke engine.

However, I do not think my comparison formula made any difference in the Rotary engine comparison - to the other combustion engines performance.

515370

[powerabout]

How high can a rotarys compression ratio be?

[Rotary John]

The trochoid and rotor shapes are mathematical expressions. As such, the max compression is dictated by the geometry chosen at the start. What is known as the "K" factor (r/e- generating radius over eccentric) determines the max compression due to geometry. The race engine started at 8.5/1 and went to 10/1.

[powerabout]

The trochoid and rotor shapes are mathematical expressions. As such, the max compression is dictated by the geometry chosen at the start. What is known as the "K" factor (r/e- generating radius over eccentric) determines the max compression due to geometry. The race engine started at 8.5/1 and went to 10/1.
Was that the max?

[Rotary John]

I don't recall

[powerabout]

I don't recall

is a rotary more or less prone to detonation and or poor fuel?
Happy on methanol?

[Rotary John]

is a rotary more or less prone to detonation and or poor fuel?
Happy on methanol?Because of the long flame travel and slow burning, the rotary can run on low octane fuel w/o fear of detonation. The race engine ran on 87 octane pump gas. The rotary loves alcohol as it has higher heat of vaporization and requires a higher volume of fuel. Both are good for internal cooling.

[Rotary John]

I find it very interesting that 50 yrs. later there is still a lot of interest in the OMC rotary race engines. I wonder what the turn out would be if one would run again for exhibition?

[powerabout]

I find it very interesting that 50 yrs. later there is still a lot of interest in the OMC rotary race engines. I wonder what the turn out would be if one would run again for exhibition?

As you know a 2 rotor can make more power today so even a 3 rotor race outboard would be a weapon today

[lars strom]

I find it very interesting that 50 yrs. later there is still a lot of interest in the OMC rotary race engines. I wonder what the turn out would be if one would run again for exhibition?

Absolutely John..and the funny part is the Rotary race engine got lots of attention in Swedish media also 1973.
Swedish media was not famous for writing about boat racing but the OMC Rotary got headlines.

It was only Mercury and Jackie hating the OMC Rotary.:)

https://www.screamandfly.com/attachment.php?attachmentid=515437&d=1676331576

[Lake X Kid]

https://youtu.be/BwM6JJYPzkM

[RogerH]

Wow, what a fantastic video. Finally a video that isn't "politically correct". ALL of our social media should be this frank & honest.

[jackiewilson]

Absolutely John..and the funny part is the Rotary race engine got lots of attention in Swedish media also 1973.
Swedish media was not famous for writing about boat racing but the OMC Rotary got headlines.

It was only Mercury and Jackie hating the OMC Rotary.:)

https://www.screamandfly.com/attachment.php?attachmentid=515437&d=1676331576
WHOA — HOLD ON THERE LASSIE ——- I HAVE NEVER “HATED’. The Wankel —- all i stated were “THE FACTS —AND NOTHING BUT THE FACTS”.
NOT ONE SINGLE CAR MANUFACTURER EVER MADE A SUCCESS OF IT [ MAZDA DROPPED IT BECAUSE OF THE LAW SUITS ON UNRELIABILITY.]
WHEN DAIMLER -BENZ AND ROLLS ROYCE ——-DROPPED THEIR LICENCES ALONG WITH THE ITALIAN -FRENCH AND AMERICAN MARQUES — I HAVE THIS FUNNY FEELING THERE HAS TO BE A FUNDAMENTAL FLAW IN THE DESIGN.
Lets face it the most ROTORY’S Running at any one time in OMC was 6 [six] .
End of any race it was usually only one and that was on a wing and a prayer.
I love anything new in powerboating —- it was a bold and brave idea—- if it had ever been any good [and available] i would have bought one.
HAND ON HEART— I HAVE NEVER “HATED THE ROTORY”
YOU ON THE OTHER HAND HAVE EXTOLLED VIRTUES IT NEVER HAD —- IT WAS THIRSTY ——EXPENSIVE—-UNRELIABLE——-NOISY——FAST. [WHEN IT WAS UP AND RUNNING]
ALWAYS CAME ROUND FIRST AT PARKER —- BUT THAT WAS IT —- NEVER SHOWED FOR THE SECOND LAP ????????????
EVEN OMC THREW IN THE TOWEL ON THE PROJECT——- ONLY A HANDFUL WERE EVER MADE —AS FAR AS I KNOW THERE ARE ONLY 4 [FOUR] STILL LEFT IN EXISTENCE ???????

It was a brave and bold venture by CHARLIE STRANG, but it clearly was never the raging success that you claimed it was . [just the facts Lassie —nothing but the facts}
Just when I thought we were getting on so well again!!!!!!!!!!!

[Rotary John]

Jackie: Your "FACTS" are wrong, and you have a definite negative bias towards the rotary. Mazda did not drop the rotary because of lawsuits. As a matter of "fact", they are still producing rotaries. One running hydrogen and another as a range extender in a hybrid. The RX-8 was discontinued due to emission standards, and many are still running today with more than 100,000 miles. "Never showed up on the second lap"; wrong again. Posey ran for over an hour and if my memory is correct lead all but the 7 l hydro for that period of time. " Wing and a prayer" Galveston 1-2-3-4; Provo, won and lapped the field several times; Lake Carol 1-2-3-4, By the way, what happened to the Cosworth KT at Parker? Anyone who has the gaul to take a F-1 automotive engine, lay it down and couple it to a stern drive and try to call it and outboard, shouldn't be criticizing others. Even though the same UIM that you have repeatedly called inept, unqualified and complete idiots OK'd it. Parker didn't. Enjoy your holiday and leave the rotaries alone. Ask your buddy Bill about
526988 them in Paris.

[jackiewilson]

Ok Johnno so if they were that good ——why did OMC drop Them.?????
Just how many did OMC produce in total [outboards that is]?????
So quote me the rotory cars that Mazda are producing today —-not experimental——hydrogen ==electric or any of the cuckoo land stuff .
THERE WERE OVER 7,000 LAWSUITS IN THE USA ALONE AGAINST THE MAZDA ROTORY
Twas not a case of me “having the Gall” to call the COSWORTH an outboard——according to the UIM [who i still have a very low opinion of], it qualified as an outboard .
Anyone who did not love the Wankel has no right to an opinion—is that right ?????
Be honest Johnno——the rotory was plagued with breakages and reliability—— it simply did not come up to Muster or OMC’s standards’
Without repeating myself ——no one has ever tamed and made a success of the Wankel .
Was a good effort by OMC but never won the KEWPIE Doll >
The COSWORTH gave a good account of herself at Parker ———circumstances beyond my control came into being——which prevented it from finishing higher up the order .
WAS a COSWORTH ENGINEERING experiment——— whole project was thought of —- built —executed and then retired after less than a year [ i was only the driver who thought up the idea and approached KEITH DUCKWORTH with it !!!!!!]
Didnt the UIM give you a very hard time over the rotory —— could not be fitted into any known class- finally made an obscure hydroplane experimental class OZ the Run what you brung class—anything goes—- fit ten of ‘em on the transom if you like and it will be allowed to run. No rules or limits ?????????????

[powerabout]

Racing 2-3 and finally won Le Mans with a 4 rotor.
787 limited to 650 hp for endurance
Wiki
"The engineers at Mazdaspeed determined that fuel efficiency was crucial for achieving victory so they restricted the redline of the engine to 8,500 rpm thus reducing the power output to 650 hp (485 kW). Emphasis was put on high cornering speeds rather than attaining high top speeds at the straight sections of the track".

[techteam]

Go and buy one when you get back Jackie. https://www.mazda.co.uk/cars/mazda-mx-30-r-ev/ it will change your life :iagree::)

[jackiewilson]

Go and buy one when you get back Jackie. https://www.mazda.co.uk/cars/mazda-mx-30-r-ev/ it will change your life :iagree::)

ME—im just an old fashioned regular motorist who runs a simple trusty LEXUS 450 H SPORT. I get 35 mpg with a range of over 450 miles per tankful .
whilst i bow to your superior engineering knowledge —i simply have to rely on common sense !!!!
Nowhere in the ad for the Mazda SUV with a rotory Hi-brid does it tell me the distance i can travel on a tankful of fuel and a full charge [ tells me i can travel 53 miles on a full electric charge — which hardly fills me with confidence if i want to travel the continent, niethr could i find the final price ????
Nah— think i will stick to the trusty Lexus — while it didnt change my life ,i enjoy driving it and i do have every confidence in its performance and reliability with enough filling stations to satisfy my needs both at home and abroad.

[techteam]

Nowhere in the ad for the Mazda SUV with a rotory Hi-brid does it tell me the distance i can travel on a tankful of fuel and a full charge. "I get 35mpg"

Its horses for courses Jackie. Whats your average journey distance, bet its less than 53 miles. How much does your 450 mile tankful cost ?

Mazda MX 30 REV 282.5 mpg Total Range Electric and onboard fuel over 400 miles. Starts at 31K which for a range extended EV is pretty good. Would I buy one, NAH I'll stick with the diesel Porsche.

[jackiewilson]

Its horses for courses Jackie. Whats your average journey distance, bet its less than 53 miles. How much does your 450 mile tankful cost ?

Mazda MX 30 REV 282.5 mpg Total Range Electric and onboard fuel over 400 miles. Starts at 31K which for a range extended EV is pretty good. Would I buy one, NAH I'll stick with the diesel Porsche.

Honest to murgatroyd i did try with due diligence to find figures on the Mazda rotory—- but failed miserably.
i do apologise for not believing there was any car manufacturers anywhere fooling with a rotory—— i was wrong [often am -but loathe to admit it].
if it comes anywhere near 400 miles using under 2 gallons of fuel i would buy one tomorrow although the fact that you would not buy one and prefer the diesel Porky does not exactly fill me with confidence.

[Rotary John]

I'm afraid it's the decal on the front and has nothing to do with the diesel or rotary.

[techteam]

I'm afraid it's the decal on the front and has nothing to do with the diesel or rotary.

You know Ann, John. When I suggested one she said Mazda? They make light bulbs don't they........