Hot Singles ! - Pictures

[Rotary John]

I have never seen any of OMC's rotary motors run but I have seen one airplane and several race cars powered by Mazda's rotary engines. The one thing they all had in common was a very unpleasant exhaust sound when running with open exhaust systems. Did the OMC motors sound much like the racing Mazdas?

When we were developing the exhaust system for this engine we ran 4 open stacks on the dyno. It would peg the sound meter at 140 db. It also caused you belly to go in and out about 2 inches as we were in the dyno room at the time. With the exception of the 2 Parker engines, I hand adjusted each carb for every engine ran after that. That meant standing on the side of the dyno and turning the high speed jet. I'm about 40% deaf (my wife says 90%) now because of it.

[Rotary John]

Wrong again Johno the designation of the ON class-----Whilst the hull is free , the motor shall have a maximum capacity of 2,000cc. and where on earth did you get the "vertical" crank from, over 50 years in boating and that's the first time i heard that one.
The designation of an outboard according to the UIM is-------It shall be removable from the hull, complete with it's drive----end of.
6 wins in the whole of it's life---That's the wankels claim to fame is it------shudder to think just how many wins the Merc has had----impossible to count but i know it's in the thousands-----even i had more wins than that, and i'm just one of the hundreds of satisfied customers. But then Johno you wouldn't know about those kind of folk---OMC never even sold ONE.

You were lucky--you only had to battle with Mercury----i had OMC on my tail as well as Mercury.

Jackie: Go look up the APBA rule for ON in 1970.OMC actually sold better than 15,000 rotaries.

[jackie wilson]

Jackie: Go look up the APBA rule for ON in 1970.OMC actually sold better than 15,000 rotaries.

Sorry Johno, i only raced twice in the USA Havasu 1970 and Parker 1978 /ish so i was never compliant with APBA rules.
I know the UIM rules for ON , backwards, upside down and in Yiddish and Hindi sideways, and nowhere is there a mention of a vertical crank. Just a 2 Litre limit.

[jackie wilson]

Were those Washing machines or Lawn mowers

[Rotary John]

Sorry Johno, i only raced twice in the USA Havasu 1970 and Parker 1978 /ish so i was never compliant with APBA rules.
I know the UIM rules for ON , backwards, upside down and in Yiddish and Hindi sideways, and nowhere is there a mention of a vertical crank. Just a 2 Litre limit.

Its why you couldn't run your IO as an ON outboard at parker and they made you run KT

[Rotary John]

Were those Washing machines or Lawn mowers

Actually it was 35 & 45HP snowmobiles. The basis for the race engine.

[jackie wilson]

Its why you couldn't run your IO as an ON outboard at parker and they made you run KT

Wrong yet again R/J, boy oh boy do you ever keep swallowing that left foot on a regular basis.
The DFV Cosworth was 3 Litres so could never run the ON class which was max 2 litres
The reason i ran KT at Parker was because the referee George May asked me to, only 4 KT boats had turned up, and they needed 5 to make a class.
I didn't care where the hell i ran as long as i did run.
When we finished we were some 5 laps in front of the next KT, (Jack D'Eath) but according to George i was running an UN_AMERICAN engine. for crying out loud, what on Gods earth is more American than A V8 FORD ???????
I was never "MADE" to run KT.

[willabee]

The only battle we had was with Merc. They didn't want to have it in a race with them because they would get beat. Besides as you said OZ was unlimited. So was ON back then. The only requirements were 17' min boat, a vertical crank and the motor had to be designed as an outboard.

Okay, I need to talk about this for a minute. I'm confused about how the classes were structured back then. Seems like OI was the big class and had a 90 in. limit until Merc came out with the 100 in. in the late sixties. Those motors were put into ON, was there an OZ at that time? In 73 both Merc and OMC run 120 in. motors, what class were they run in?

OMC wasn't allowed to run the rotary at Paris that year, that's why I'm thinking there was no OZ or did OZ have a 120 limit then? UIM maybe thought the rotary displacement was more than 120 in. and there was no provision for a motor that big?

R.J., this must be the four stack ear drum wacker.... I say, R.J., this must be the four stack ear drum wacker ..... Ah, um ..I say R.J., this must be the ..... nevermind, just look at the picture.

[Rotary John]

Okay, I need to talk about this for a minute. I'm confused about how the classes were structured back then. Seems like OI was the big class and had a 90 in. limit until Merc came out with the 100 in. in the late sixties. Those motors were put into ON, was there an OZ at that time? In 73 both Merc and OMC run 120 in. motors, what class were they run in?

OMC wasn't allowed to run the rotary at Paris that year, that's why I'm thinking there was no OZ or did OZ have a 120 limit then? UIM maybe thought the rotary displacement was more than 120 in. and there was no provision for a motor that big?

R.J., this must be the four stack ear drum wacker.... I say, R.J., this must be the four stack ear drum wacker ..... Ah, um ..I say R.J., this must be the ..... nevermind, just look at the picture.

My memory might be all screwed up, but I don't recall an "OZ" class in '73, at least for APBA. I remember "ON" being the unlimited class at the time and "U" class being the 100ci class. There weren't any 122" motors at the time so ON fit anything else bigger than 100ci as long as it was designed as an outboard. I don't know what UIM had at the time. I believe "ON" was changed later to 122ci when Merc found out that the production OMC engine was 150ci. I was told politics keep the rotaries out of Paris in '73 but were allowed to run exhibition in '74. As I'm sure you are aware, Merc was trying anything they could to keep the rotaries out of a race the factory wanted to enter. The picture has horns on the CARBS. This was a publicity photo only as that was only a 100HP dyno its sitting on, the carb horns wouldn't fit in the bucket and were never used. The exhaust pipes we tested were straight 2" dia SS; 4 of them. We started at 20" and cut 2" off at a time down to 4" and ran a dyno curve at each length. The best compromise length was packaged in the manifold you see in some of the pictures. There were only 6 of these manifolds ever made. After Parker, all dyno testing was done prop shaft with the complete exhaust system using a gearcase. I wish I had some of that hair today. RJ

[jackie wilson]

The O Designation was stolen from the hydroplane classes.
OZ has been an unlimited class since time immemorial Remember OE/ON/OX/OZ?

[Mark Poole ModVP]

Notice those carbs are the single barrel ones used on the 2 and 3 cyl. loopers of the day.

Does anyone remember the carbs used on some of the OMC snowmobiles? Big single barrel carb with an accelerator pump. I know of at least one 3 cyl. outboard that had a set of these on it.

[T2x]

The O Designation was stolen from the hydroplane classes.
OZ has been an unlimited class since time immemorial Remember OE/ON/OX/OZ?

OE/ON/OX/OZ/OMC........Story of O...... Oh My!

[willabee]

[QUOTE=jackie wilson;2497043.....OZ has been an unlimited class since time immemorial Remember OE/ON/OX/OZ?[/QUOTE]

Did time immemorial begin in 1974?

If there was a class for them, why didn't Paris let them run, but Windemere did?

Were multi engined outboards not allowed in Paris?

[jackiewilson]

Did time immemorial begin in 1974?

If there was a class for them, why didn't Paris let them run, but Windemere did?

Were multi engined outboards not allowed in Paris?

Paris was a rule unto itself, ruled with a rod of stainless by Msr, Bladiniare.
Was for single engines only as far back as I can remember.
There was also an experimental class where almost anything with a motor, including turbines were allowed to run, but were not eligible for classification.
Can only think that the Mercury clout (or money) was bigger than OMC's on that particular occasion.

What's with the cranky ask ( did time immemorial begin in 1974 )? OZ WAS UP AND RUNNING YEARS BEFORE THAT.
LIKE I SAID, THE O CLASSES WERE HYDRO -----THE RUNABOUTS NICKED 'EM.

[robertpitter]

love this thread