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The rotaries had NO mid section. in 1973. It always amazed me it to OMC that long to realize that on the 2-strokes, the lower CG helped handling. I guess the rotary haters, Kuney and Blanchard just could admit that the rotaries had some good ideas.Quote:
Originally Posted by lars strom
Yes John, the rotary design was very clever.Quote:
Originally Posted by Rotary John
The funny part with this is the new Merc UIM F1-V8 racing engine for next years racing is using a 12 inch mid section.
John..I spent two weeks with Don Kueny on a trip to Stockholm, Sweden in the mid nineties to investigate an Donzi/OMC King Cobra accident outside Stockholm. I could tell already after a few days with Kueny he was not a friend of any racing stuff..:)Quote:
Originally Posted by Rotary John
They have to put the overdrive somewhere. Can you imagine the amount of torque steer if they just ran it straight to the lower unit. Prop pitch would be insane.
Quote:
Originally Posted by lars strom
The gearcase ratio worked fine for the powerful OMC UIM F1-V8. Todays UIM F1 boat all use electric power-steering.Quote:
Originally Posted by lars strom
@2us70
The breakthru for low CG didn't come with the V8 program. It was spawned by OMC in the mid 60's with the 9.5 hp fishing motor. I should know as I have 6 of them hanging in my barn LOL:smiletest: Best low-pro design ever produced!Quote:
Originally Posted by Rotary John
All new F1-V8 with old school steering arms? I would have expected something that looked more like an off shore hook up?Quote:
Originally Posted by lars strom
It would be interesting to do a side by side comparison of the old and new F1 V8s.
Never going to happen for two reasons..Quote:
Originally Posted by 2us70
Even if someone dig up an OMC F1-V8 to compete in the UIM F1 series it’s not going to be allowed.
Its a spec. class today..Only Merc product are allowed.
Not even sure if they are going to let the Merc V6 in to race next year..
Would be a very bad deal if a Merc V6 won..:)
Rotary John, I always thought the rotary engines used by NSU and Mazda were 4-strokes (?).Quote:
Originally Posted by Rotary John
If the OMC Rotary was 2-stroke how did you do that?
Something got lost in the translation. The rotary is a 4-stroke. What I was trying to say it took OMC 10 years to realize a lower center on gravity by using a 6" mid section on the V-8 while the rotary had no mid section back in '73. Many of the features used on the rotary were later used on the 2-stroke racing engines. Know why there are no 14/23 Rotary gearcases left?; they were scavenged for parts for the V-6/V-8 Programs.Quote:
Originally Posted by peterse90
Don Kueny and Jim Nerstron were busom buddies. I can't speak of his attitude towards racing, but he had an extreme hatred for the rotary and anyone involved with it. Kueny being appointed Chief Engineer to replace Hulsubus was the direct cause of the entire rotary engineering team leaving OMC within a year of his appointment.Quote:
Originally Posted by lars strom
Well.. I spent 2 weeks with Don Kueny over in Sweden and pretty sure it was 1994.
If I remember correct he retired from OMC the year before.
A very interesting man and he told me a lot of good and fun stuff.
A great man. Don’t remember him talking about the rotary, but we talked about mostly production OMC outboards.
We did visit his home in Kenosha a few years later with our motorhome.
I did google Don Kueny and found this..
Attachment 474022
Attachment 474023
Attachment 474024
When you think back on it, I think the focus was more on the 'revolutionary' combustion design of a rotary and that OMC stacked 4 of them. If I remember correctly very little was made of the fact that they were 4-strokes. Now looking back over 45 years ago, think now with the introduction of Merc's new 4-stroke Formula 1 engine just how ahead of the curve the OMC rotaries were. Same could be said about the OMC V8's.Quote:
Originally Posted by Rotary John
Timing is everything !!!!
Now I know why when I heard Jimbo run a rotary in Peterborough, Ontario 1973 it sounded so different.
old wire and pulley with a power assisted helm is pretty close to perfect till linear actuators can do the job.Quote:
Originally Posted by WaterZebra
Not only were the rotaries a 4-stroke, the exhaust cycle lasted for 270 degrees of crank rotation for each flank of the rotor. Couple this with the fact 2 rotors were exhausting at the same time and for part of the cycle all 4 were exhausting; aka a unique sound. In one cycle of the crankshaft (360 degrees) all 4 rotors exhaust. In fact exhausting is continuous for each rotor. As the apex seal closes for on flank of the rotor it opens the next flank to exhaust.Quote:
Originally Posted by peterse90
To my knowledge, the sound of an OMC rotary was never recorded? If the rotary was a 4 stroke, where was the oil reservoir located?Quote:
Originally Posted by Rotary John
It didn't have one. There are 2 types of rotaries, both of which are 4 strokes. The rotor is a captive heat source, that is there is no external way to remove heat from it. Mazda uses what is call an oil coiled rotor. Oil is circulated inside the rotor to cool it and then run thru a heat exchanger to remove the heat. A pressurize oil system also allows the used of babbitt bearings, but requires oil seals in the rotors to insure oil isn't leaked into the combustion area. The OMC race rotary (and snow mobile) was charged cooled. The incoming gas/air charge was passed the rotor cooling it. Oil was mixed with the gas similar to a 2-stroke to lubricate the roller bearings. Using the charge to cool the rotor heated it up considerably resulting in reduced airflow (less volumetric efficiency). This was the trade off of the 2 cooling methods. The oil cooled had higher volumetric efficiency; HP, at the expense of more parts, more weight and higher friction losses. The charged cooled is simpler and lighter but lower HP.Quote:
Originally Posted by WaterZebra
Attachment 474094
Gene Thibodaux won the 1986 F1-V8 World Championship title but sadly passed away 2016.
http://svera.se/blogg/gene-thibodeaux-won-the-1986-f1-v8-world-championship-title-but-sadly-passed-away-2016/
In the mid 70s I was working on a crash fire unit at a local airport. An airline pilot was trying a new approach to unlimited air racing. He designed and built a small twin engine airplane to compete with the warbirds that made up the class. His plane was powered by 2 Racing Beat Mazda rotary engines. Every time he flew it the airport got noise complaints. I only heard it with both motors running once. It was LOUD and HARSH. Even with only one motor running it was unpleasant. The motors were arranged in a puller/pusher configuration and he never got the rear engine to cool properly. One result of this was we got to watch him land it a lot since he would have to declare am emergency each time. I think he finally ran out of money and patience.Quote:
Originally Posted by WaterZebra
I was listening to this #03 Evinrude powered ScottiCraft for close to 6 hours in Paris 1974.Quote:
Originally Posted by 2us70
(The two drivers was Jimbo McConnell & Barry Woods)
I don't remember this unique racing outboard extremely loud but a very special great sound. @Rotary John
https://www.screamandfly.com/attachm...5&d=1601235493
I think the OMC rotaries may have been run down here once. I am pretty sure I was not there if they did since they were pretty distinctive. So I have not heard how they sounded. I have heard a few Mazda race cars and can say that it must be a acquired taste. Most places required them to run mufflers.
Ben was mainly driving a Johnson F1-V8 but sometimes the better looking Evinrude..:)Quote:
Originally Posted by lars strom
Bob Schubert
Attachment 474128
Was a good run with Bob at the November 2015 Tavares OFF / Vintage event. Outstanding Lee/Johnson restoration. We need to do this again..maybe with the Hering or 888 Molinari next time.
Attachment 474139
One I always liked
WOW..think about this..OMC raced a winning 4-stroke racing outboard in the UIM F1-OZ class already 1973. (47 years ago)Quote:
Originally Posted by Rotary John
http://svera.se/blogg/omc-and-the-ro...ndermere-1973/
https://www.screamandfly.com/attachm...5&d=1601307844
Next..a winning 3.5 liter V8 racing outboard in the UIM F1-OZ class 1981. (39 years ago) below
http://svera.se/blogg/f1-v8/forst-till-bojen/
https://www.screamandfly.com/attachm...4&d=1508289790
We also know OMC stopped racing the F1-V8 by Charlie Strang's order after the 1989 season. Read Mr. Strang's report.
http://svera.se/blogg/omc-f1-v8-raci...harlie-strang/
OMC closed down December 2000. (11 years later.
First lap Parker 1973, Jimbo McConnellQuote:
Originally Posted by largecar91
A better picture from Parker 1973.
Attachment 474146
In IMSA road racing in the ‘80’s, the RX7s Ran mufflers and were still obnoxious loud!
Quote:
Originally Posted by 2us70
Imagine what it was like being in the dyno room developing the exhaust system on the rotary. 4 straight pipes cut off 2" at a time. It pegged the sound meter. And I wonder why I'm mostly deaf?
I am sure the rotary engines was really loud inside a building wide open.Quote:
Originally Posted by lars strom
Maybe I got used after a few hours in Paris but it was a very unique sound.
I loved it..:cheers:
Question for Kathy McConnell ? Is this Jimbo or Barry driving the Evinrude and Bill or Tom driving the Merc?Attachment 474189
I dont think Cathy are here at S&F @Rotary John.
Only on my Evinrude FB page.
(Mr. Bill & Cees Van Der Velden was driving the #12 boat)
http://svera.se/blogg/paris-6-hours/...our-race-1974/
Attachment 474195
This is where I found the Evinrude Rotary picture in Paris 6 hours 1974 for 12 years ago.
Attachment 474196
This is from Yachting & Boating Weekly about the #03 Evinrude powered rotary at the end of the Paris 6 hour race 1974.
Attachment 474198
More from Yachting & Boating Weekly and Paris 1974. (first picture, second is from a Swedish news paper)
The #48 OE class Clerici/Evinrude did a great start (red dot). Run all the 6 hours without any problems and finished third in a field of 39 OE class boats.
Attachment 474200
Attachment 474201
Attachment 474202
That is absolutely my kind of boat race!
In the ‘80’s IMSA had a road race through down town Columbus.
The Mazda rotaries ran in the GTU class which was (production based but heavily modded cars, full tilt motors) 3.0 liters and under and even w/mufflers they were louder echoing off the city buildings than the GTP (5.0 and over factory prototypes) V-12 Jags w/open headers!
Even though the factory Jags couldn’t beat the factory Porsche’s, their sound was orgasmic!
Quote:
Originally Posted by Rotary John
I adjusted all the carbs on every rotary race engine after Parker, There were studs in the manifold and star nuts holding the carbs on. Having physically adjusting the carbs on this engine, I can factually say the nuts were tight when It came off the dyno, After the race not one, but all 8 carb nuts were loose and the carburetors were just hanging. Not ever before or after the Paris race was even 1 carb nut loose, which let me to believe someone loosen the nuts after testing in Brugge and before the race. Posey's engine had all of it's carb nuts tight, though he hit a turn boey and didn't finish the race. As I recall Woods had trouble getting the engine to start at the beginning of the race which would further indicate the carbs were loose at the start of the race. With the carbs loose, the engine would have sucked excess air causing the lean running and bearing failure.Quote:
Originally Posted by lars strom