Facts about Evinrude/Johnson racing outboards made my OMC

[lars strom]

Fred Kiekhaefer

Fascinating to read.
Thank you.


Fred Kiekhaefer

In the early 1970s, I tested several wankel powered cars for my father - including an NSU RO80 and a Toyo Kogyo Cosmo Sport - when he was considering marine applications. Every one was smooth until they broke.
Cracked blocks from excessive heat - every time.

@Lake X Kid ..Ugly or not..

Pretty interesting member/person making comments about the OMC racing rotary at my FaceBook page.

[lars strom]

#44 Dario Eugenio Grassini UIM Formula 3/OE. Molinari/Evinrude CC

Stockholm GP 1984.

[lars strom]

1979 Evinrude advertising.

[lars strom]

CCC and the Rotary.

[lars strom]

Evinrude E-TEC G2 V6 3.4 liter.

Chloe Khan showed off her tan lines and her curves in a tiny black bikini as she relaxed on a yacht..






Attachment 426523

Nope..I still don't know who she is..!!..

[Rotary John]

@WaterZebra..

Haahaa..you are really paying attention to details. That's a good thing.
Only @Rotary John could have the answer to your question.

The picture with Ralph Evinrude shows the actual props used. I believe this picture is from Miami into. Switching prop direction and size was a trick used confuse Merc.

[Rotary John]

CCC and the Rotary.

The view merc. T-3 drivers saw most of the time.

[Rotary John]

I'm looking at the Johnson rotary on the stand with a LH prop and then the photo of the boats on trailers with RH props. Which direction?

Mike Griffith is the other Engineer in the photo. He was instrumental in the design and development of the rotary race engine.

[WaterZebra]

The picture with Ralph Evinrude shows the actual props used. I believe this picture is from Miami into. Switching prop direction and size was a trick used confuse Merc.

RJ - It's safe to assume that the "bucket" was a single piece aluminum casting (gearcase, swival pin, steering bars and engine and top cowl attachment, etc). At rest, where did the waterline end up with the boat sitting in the water? Did submerged back pressure bother the wankel? Was the exhaust "top stacked" to deal with the waterline?

It's a national tragedy that more still photos and videos were not taken at the time!! I also believe that the break thru technology involved was poorly managed by OMC. Regardless of race committee pit rules, the boats and engines should have been locked away in garages with security personnel just like Area 51.

[lars strom]

.. At rest, where did the waterline end up with the boat sitting in the water?

Here..

[lars strom]

From the 1974 Johnson Sales brochure and OMC is promoting the Stinger GP V4 race engine and the Rotary.

[Rotary John]

RJ - It's safe to assume that the "bucket" was a single piece aluminum casting (gearcase, swivel pin, steering bars and engine and top cowl attachment, etc). At rest, where did the waterline end up with the boat sitting in the water? Did submerged back pressure bother the wankel? Was the exhaust "top stacked" to deal with the waterline?

It's a national tragedy that more still photos and videos were not taken at the time!! I also believe that the break thru technology involved was poorly managed by OMC. Regardless of race committee pit rules, the boats and engines should have been locked away in garages with security personnel just like Area 51.

You are correct; the bucket was a sand cast aluminum part that the lower end of the swivel bracket, gearcase, steering arms, engine and shroud attached too. The upper end of the swivel bracket attached to the top hsg. of the bottom engine. The exhaust manifold had individual tunes pipes that ended at the bucket/shroud split line that dumped into a collector. there was also some trick stuff in the exhaust that I never have told about. The initial engines had a pulse drive fuel pump that was to pump any water that got into the bottom of the bucket. It was dropped later on as water was never a problem in the bucket unless the entire engine went under. Lars post a couple of pictures showing the water line at rest. Notice the 2 brass pipes extending out of the back at the split line? They were exhaust relief pipes tapped into the collector. We always used them but I'm not sure they were really needed as the rotary in a 4-cycle with a positive exhaust cycle. I'll see if I can find a couple more pictures. I know Strang always had his camera around his neck and was always at the races, but I don't know what has happened to them. Barb may still have them, or they may have been thrown away. Remember this was 50 yrs. ago. OMC also knew Merc. was playing with rotaries also (Ben Shafer). Therefor secrecy was of the upmost with this project. Many if not most of the engine details were never revealed until BRP bought OMC and had no interest in the rotary, and I wrote " the real truth". I even got permission from BRP before I published it.

[Rotary John]

Attachment 524537Attachment 524538Attachment 524536
Here's a couple showing the basic engine in more detail. The blue item in the cut away bucket is the exhaust collector that the manifold pipes dumped into. The last is my favorite. Paris 1974. I don't know if that's Jimbo or Barry passing the Merc. T-3 for the umpteenth time.

[Rotary John]

Nope..I still don't know who she is..!!..

That gal has more silicon than Dow Chemical.

[BLisBack!]

Maybe I missed it but...(last couple posts were a bit distracting ) Why did OMC decide to not go to production with the rotary? The block issues?

-BL