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

[jackie wilson]

Thanks for a wonderful insight into the OMC effort at taming "The Rotary". Should be the answer to all our prayers, on paper at least, silent , powerful, lasting etc. That's the very first time i have heard that it was economical. I have only touched the edges of rotary technology, and am still surmazed that NOBODY ever tamed it and made a fortune. Bigger corporations than OMC have tried, but with only limited success. The only good thing i would agree with is it's smoothness. The ones i have been around ,have been thirsty, very loud in a sportive kinda way and needed much maintenance. The exception to that was my daughters little Mazda that she kept for 5 years and mostly trouble free but the residual value was a bit horrendous.
Raced against the OMC Rotaries in Paris and Windermere. We were always worried in case they didn't break but they were Generally grenades except Windermere, at least that was what Oshberg would have us believe.
The take out brigade was not confined to Mercury as you must well know, those sort of tactics were used by both sides, if we ever get to meet, we will swop tales on dirty deeds and daring do. The amazing thing is ----if it was ever that rife between the camps, how come all the drivers alive today are still good friends. Notwithstanding that, i have been known to have mild disagreements leading to fisticuffs, due to an opponents extraordinary antics whilst competing with me for minor rewards {ie. driving like a pratt}.
Again thank you for an amazing insight into the rotary.

[Mark75H]

I agree with Jackie on the factory wars stuff. I don't think Merc had as much influence in France as is implied in this story. The French were very hard headed about new technology. They had done the same "run only as experimental/demonstration" with the first tunnel hulls a few years earlier. Anything not made in France or at least generally sold widely in France would have been prohibited the same way.

Technically there was no procedure or spec in UIM on how to measure the displacement of a Wankel, so they could not determine the displacement being correct for any particular class OMC would have entered them in.

[jackie wilson]

Bear in mind ---THE UIM RULEBOOK--- was written in French and even today is merely translated from French which leads to many misinterpretations. I suspect the original APBA rulebook used the UIM book in it's foundation.
Regret to say some of the UIM personnel have left a lot to be desired over the years and have been as bent as as an eleven sided three penny bit {$2 bill to colonials}. Decisions have been bought sooner than democratically decided, There have been exceptions to this statement, but they were a minority.
Generally speaking you could "run what you brung" in all French races, there was an "EXP" class which catered for all things, which is why tunnels and Rotaries were allowed in the first place,'cos there were no listed classes for them.
You cajole the French,{ bit like leading a horse to water} wave a stick and their backs get up, i have had a few 'ups and downs with the UIM over the years, and on balance would say the scales are evenly balanced in the Merc V OMC tussles.

[blkmtrfan]

Great thread thanks for taking the time to write it and post

[willabee]

THE PARKER RACE

We had two boats at Parker. The Evinrude was driven by Jimbo McConnell and the Johnson by Tommy Posey..... The race went off as scheduled and everyone held their breath to see who would lead the first lap. Here they came with the two rotaries side by side;....Jimbo and Tommy coolly drove by the crowd waving as they went. A big wave went to the Mercury camp as they flew by..... Mike and I were all smiles and feeling pretty good about all the long hours and work we had put in. As the boats approached for the second lap, Tommy was still in first by a big margin, but Jimbo was nowhere to be seen. We found out shortly his engine had failed. Tommy continued to lead, but succumbed to engine failure before the first hour was complete. <!-- / message --><!-- sig -->

This was all very interesting reading. It sure was a lot of work, thanks for taking the time to do it. However, I still feel the need to make a few corrections (it's a dirty job, but someone has to stand up for Merc).

When Jimbo and Tommy completed the first lap turn, they did not "fly by" the Merc pits. They actually slowed down, drove closer to shore and raised their face masks to show very big smiles as they waved at the Merc pits. I remember it well, it was very impressive.

No biggie, but Powerboat says it was Tommy that broke right after the first lap. The hydro passed Jimbo on the 3rd lap and Seebold passed him shortly after that. Jimbo didn't run with full power for very long.

[jackie wilson]

Be kind to the afflicted Willa. he didn't lie----laps one and three must have been in the first hour-----But they were quick for five or ten minutes or so!!!!!!! Bet OMC didn't put a lot of endurance time like 5000 miles or three months nonstop, y'know the everyday story of life at Lake X Blah-Blah-Blah.

[LIQUID NIRVANA]

Yes, the OMC Scotti boats were meant for V4's not rotary's or V6's etc. You had to be an exceptional driver to run drive those . AND certainly not a lot of time or money invested in boat setup & testing & props either. I think the props were made inhouse at OMC as well. VERY VERY different to the Merc way of doing things. RACING was not a priority or the way of life at OMC other than for testing purposes.

[LIQUID NIRVANA]

1. Jimbo at Parker, first lap waving to the crowd. The wake behind him was Posey.

2. Posey at Provo

3. Posey at Miami Marine stadium at press intro befor Parker. Note no fuel filler caps the bost rear shroud.

4. Posey at Provo. Look carefully, nothing in the water, he was really flying.

5. Very early press photo; note vertical "Johnson" 15/17 gearcase

6. OMC Engineering boat dock. Mike Kukla (died 1975)behind engine, Harold "Mouse" Wade. 14/23 gearcase used at Provo. Note the cut off exhaust exit and the black spacer between the gearcase and the bucket. The was a V-4 gearcase modified for the rotary. Later in the program a new gearcase casting was made for the 14/23.

[NNT]

A rotary long lastin? Every Rx7 I have seen with over 75,000 miles on it smoked to some extent, and the higher mileage ones can keep the skeeters away with no problems.

[jackie wilson]

You had one of the worlds most respected prop men in Hendricks, at that time you could count the prop men on one hand. Mercury only had Dick Snyder but he was just temp. Tried to get Mercury to use Rolla, but as usual they knew best, and the props provided were 3rd class at best, OMC had better gearcases and props than Mercury. On reflection , i would say OMC spent plenty on race development.

[whipper]

Very interesting post! Ive always wondered why there wasnt a rotary powered outboard today. The power to wieght is only second to a turbine. The rotarys also have very flat tourque curves. Theres a guy making 3 rotor motors with a turbo pushing 300+ hp with 300 torque for inboards. Hes called Rotary Power Marine. He makes some sweet motors. I asked him once what it would take to make these motors a drop on and he wasnt sure. Not an outboard guy. I think its possable? he wants 10 grand for a new 300 hp turboed monster. Thats not all bad. Great info!

[LIQUID NIRVANA]

[LIQUID NIRVANA]

DYNAMOMETER Testing






A later DYNOMOMETER SHEET showing 313 propshaft horsepower @ 10500rpm with 217 crankshaft ft Lbs of torque @ 5000rpm

[Old fiberglass]

Thanks for sharing your info, pictures and insight....awesome amount of detail. What was the all up weight of a rotary.....power to weight ratio.

[jackie wilson]

yes, the omc scotti boats were meant for v4's not rotary's or v6's etc. You had to be an exceptional driver to run drive those . And certainly not a lot of time or money invested in boat setup & testing & props either. I think the props were made inhouse at omc as well. Very very different to the merc way of doing things. Racing was not a priority or the way of life at omc other than for testing purposes.

you amaze me with the statement------racing was not a priority or a way of life at omc. I went to the omc facility in brugge belgium and i can tell you they were as fanatical about racing there as mercury were in oshkosh. Did you ever tell the likes of barry woods and cees velden, posey and sanders and jimbo that racing was not a priority. Don't know which planet you were on at the time----but i would not have liked to race against omc if they ever decided to make it a priority.