Facts about Evinrude/Johnson racing outboards made my OMC

[Rotary John]

Rotary John, I always thought the rotary engines used by NSU and Mazda were 4-strokes (?).
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.

[Rotary John]

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..

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.

[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..

[peterse90]

Something got lost in the translation. The rotary is a 4-stroke.

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.

Timing is everything !!!!

Now I know why when I heard Jimbo run a rotary in Peterborough, Ontario 1973 it sounded so different.

[powerabout]

All new F1-V8 with old school steering arms? I would have expected something that looked more like an off shore hook up?

old wire and pulley with a power assisted helm is pretty close to perfect till linear actuators can do the job.

[Rotary John]

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.

Timing is everything !!!!

Now I know why when I heard Jimbo run a rotary in Peterborough, Ontario 1973 it sounded so different.

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.

[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.

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?

[Rotary John]

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?

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.

[lars strom]

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/

[2us70]

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.

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?

[lars strom]

.... Every time he flew it the airport got noise complaints. I only heard it with both motors running once. It was LOUD and HARSH...

I was listening to this #03 Evinrude powered ScottiCraft for close to 6 hours in Paris 1974.
(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

[2us70]

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.

[lars strom]

A very nice friend was visiting us at Lake of the Ozarks today.
Tim Schroer use to work for OMC at many different positions. Tim is also a big boat racing fan and did work for OMC racing. His album of racing pictures is large Tim is going to let me use many of them here at the OMC racing history thread.
Here is two examples of the # 57 Ben Robertson in his Velden/Evinrude V8.
Thanks for visiting Tim.

Ben was mainly driving a Johnson F1-V8 but sometimes the better looking Evinrude..

[lars strom]

Bob Schubert

[RogerH]

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.