Facts about Evinrude/Johnson racing outboards made my OMC

**lars strom** · 09-21-2023, 06:15 PM

Originally Posted by WaterZebra

Did the rotary compete in just clock start races? How did it do in LeMans beach starts?

Paris 6 Hours was 100% "dead engine start" 11:00 AM Sunday morning did the Race Chairman Mr. Blodinaire drop the green flag and sometimes up to hundred race boats in mixed classes took off..
The two OMC Rotary powered Scotti boats took the lead in 1974.
I remember it like yesterday.

5:00 PM the Race Chairman Mr. Blodinaire waved the checkered flag.
A fantastic boat race.

**lars strom** · 09-21-2023, 07:12 PM

Originally Posted by lars strom

Selva Outboards of Italy did develop a racing outboard for the UIM OE/F3 class.
The two Selva brothers was putting up a great fight in the OE/F3 class. We also did have a lot of fun with the two Italian brothers.
The Selva engine was fast but not fast enough to beat the OMC OE/F3 engine..even when the brothers installed the OMC carburetors. (See picture)
Fun memories.
Sadly 2012 we lost brother Lorenzo Selva way to early from health issues.

Team Selva in the UIM F3/OE class. Stockholm GP 1987.

**WaterZebra** · 09-22-2023, 08:03 AM

Originally Posted by lars strom

Paris 6 Hours was 100% "dead engine start" 11:00 AM Sunday morning did the Race Chairman Mr. Blodinaire drop the green flag and sometimes up to hundred race boats in mixed classes took off..
The two OMC Rotary powered Scotti boats took the lead in 1974.
I remember it like yesterday.

5:00 PM the Race Chairman Mr. Blodinaire waved the checkered flag.
A fantastic boat race.

Did anybody in the UIM, race committee, or event media capture the rotary on video and audio?

**lars strom** · 09-22-2023, 09:20 AM

Originally Posted by WaterZebra

Did anybody in the UIM, race committee, or event media capture the rotary on video and audio?

As far as I know there is NO audio recording of the OMC racing rotary.

This is me a few minutes before 11:00 AM Sunday morning when Race Chairman Mr. Blodinaire droped the green flag in Paris 6 hours 1974..
I remember so well when the two OMC rotary powered Scotti boats lapped me many times during the race. There was a large water spray after the rotaries like no other tunnel boat..

**lars strom** · 09-22-2023, 09:33 AM

Beautiful Johnson racing advertising from 1979.

My guess is 201 is Ken Stevenson and maybe Bob Hering in the 3 cylinder boat...He won the UIM World OE title 1978. The race was run in the USA.
Thanks for the picture/poster my OMC friend.

**2us70** · 09-22-2023, 10:16 AM

In the mid 70s a guy down here in South Florida tried to build an unlimited racing airplane. It was very small and it was powered by two Mazda rotaries. He never did get it sorted out. I was working on the airport where he was trying to test this aircraft. Every time he took off to the east over a populated area the airport got a bunch of calls about the sound. I heard it a few times and even when only the front motor was running it was pretty bad. When both motors were running it was twice as bad. We usually only heard it with the front motor because he kept having to declare emergency and land it on only the one motor. As far as I know he never got the overheating problems of the rear motor solved.

Originally Posted by WaterZebra

Did anybody in the UIM, race committee, or event media capture the rotary on video and audio?

**lars strom** · 09-22-2023, 11:45 AM

1979 Evinrude racing advertising..!!

Fred Hauenstein / Ron Hill / Evinrude V-6 CCC overall win Parker 1978.

https://svera.se/blogg/fred-hauenste...n-parker-1978/

**Rotary John** · 09-22-2023, 04:30 PM

U.S.A.: FIRST ROTARY ENGINE FOR OUTBOARD SPEEDBOAT USE SUCCESSFULLY TESTED IN FLORIDA. - British Pathé (britishpathe.com)WaterZebra You asked, here is the only video I know of with real sound. This was at the Miami introduction.

**WaterZebra** · 09-23-2023, 09:05 AM

Originally Posted by Rotary John

To my recollection, all the rotary starts were from a dead start with the driver in the boat. The rotary was always the first one back to the S/F line. I don't believe it ever ran a flying start. Johnnie Sanders once said the only other engine with the "push" of a rotary was the Wizzard; and he drove them all V-4, V-6, V-8 and rotary.

RJ - From your point of view, what would have happened to the OMC rotary program if it hadn't been killed off by the V6?

- 2 rotor production engine?
- Production crankshaft for a 4 rotor block?
- 4 rotor block?
- FNR gearcase?
- Production mid section?
- Wet sump?
- With today's engine ECU technology, would some of the problems you had with the rotary be eliminated?

What is the biggest rotary ever built? (rotor count)

**WaterZebra** · 09-23-2023, 11:45 AM

Originally Posted by Rotary John

U.S.A.: FIRST ROTARY ENGINE FOR OUTBOARD SPEEDBOAT USE SUCCESSFULLY TESTED IN FLORIDA. - British Pathé (britishpathe.com)WaterZebra You asked, here is the only video I know of with real sound. This was at the Miami introduction.

RJ - The video is great but the audio sounds like stock outboard exhaust dubbed in. I've listened to this several times and I can't make the distinction? There are very few people who had the opportunity to see and hear these things run. If you and Lars say it's the real deal I will have to take your word for it. Only thing I have heard about the rotary is it had an exhaust tone all of it's own?

**lars strom** · 09-23-2023, 12:07 PM

Originally Posted by WaterZebra

RJ - The video is great but the audio sounds like stock outboard exhaust dubbed in. I've listened to this several times and I can't make the distinction? There are very few people who had the opportunity to see and hear these things run. If you and Lars say it's the real deal I will have to take your word for it. Only thing I have heard about the rotary is it had an exhaust tone all of it's own?

After spending close to 6 hours in Paris 1974 listening to the Rotaries running in the race I do not believe the engine sound in the video are from the rotaries.
Just my opinion.

**Rotary John** · 09-23-2023, 01:02 PM

Originally Posted by WaterZebra

RJ - The video is great but the audio sounds like stock outboard exhaust dubbed in. I've listened to this several times and I can't make the distinction? There are very few people who had the opportunity to see and hear these things run. If you and Lars say it's the real deal I will have to take your word for it. Only thing I have heard about the rotary is it had an exhaust tone all of it's own?

I'm 3/4 deaf listening to the rotaries in the dyno room, but I'M not sure that's the real sound.

**Rotary John** · 09-23-2023, 01:30 PM

If the v_6 hadn't arrived when it did, development on the rotary would have continued. I had already designed and built prototype 6HP outboard. The revised 4 pcs. crank had only run once. It eliminated the single biggest failure of the race engine, the long thru bolt breaking. Rotor bearings was the next failure mode and good results was being seen in independent testing. Apex seals were on the verge of going to different materials and production processes that virtually eliminated wear and cost less than a nickel. Rotor combustion pocket design and rotor material would have been the next step in evolution. titanium rotors with leading pear shape pockets would have allowed higher RPM and as seen on the above power curve, increased HP would have resulted. Moller is getting over 100 HP from a single rotor a 6500 RPM. With today's materials and knowledge, 500 HP from the same displacement is certainly possible. However, with that said, the issue with EPA still existed. Also, Strang had made a big splash with the into and let several writers actually run one so shareholders and the general boating public were expecting to see a production version. If the rotary race program continued, that pressure would have increased. OMC research did prototype a larger displacement engine, but like most of their prototypes, it was just a feasibility study. OMC eventually sold all the tooling and inventory to Moller.
Some guy designed and built a 12 rotor engine. search the web if you're interested.
The 2 rotor 110 HP production prototype use the 3 cylinder 70 hp mid-section. the 6HP used the 2-cycle 6 HP mid-section

**2us70** · 09-23-2023, 03:01 PM

Sure doesn't sound anything like those Mazda rotaries I have heard. I don't know if OMCs rotaries were built the same as Mazdas were but they kind of look the same just more rotors.

Originally Posted by lars strom

After spending close to 6 hours in Paris 1974 listening to the Rotaries running in the race I do not believe the engine sound in the video are from the rotaries.
Just my opinion.

**Rotary John** · 09-23-2023, 04:31 PM

Originally Posted by 2us70

Sure doesn't sound anything like those Mazda rotaries I have heard. I don't know if OMCs rotaries were built the same as Mazda's were but they kind of look the same just more rotors.

The Mazda and OMC rotaries are totally different, Mazda is oil cooled internally and dumps the exhaust directly to atmosphere. The OMC rotary was charged cooled internally and mixed water in the exhaust before it exited.