The super "C" class

[Blackhawkguy]

Who know's anything about the super C class? I was reading my dusty copy of Speed and Spray and saw this class.

what kind of motors where they
how long did it exist
did it become the form E class


I know by 1977 it was not around in stock. Any old timers out there remember this class?

Kerry

[G Stillwill]

The motor was a three hole Cresent imported by Dick O'Dea and were really fast speeds faster then DSH class. There are still some around in the collectors hands now

[trident]

Super C Motor

500 cc Three cylinder Crescent looper (really a Volvo Penta?), pulse tuned closed exhaust. Quiet, light, compact, went like blazes... Marty Stahl ran one around here. Broke 90 in a Kilo if memory serves... Marty? that's your cue...

[sam]

About the time Dick started importing them, Volvo bought out Crescent and stopped making them and all the parts (there is no truth to the rumors that they are based on the Saab Sonnet car motor, nor that they were built by Volvo). Dick had to have some parts made in the US and scavenge ignition for them by the end; Volvo was not interested in keeping them in production just for US racers and - they were obsolete in Alky racing. With no new motors available and very high speeds being attained, the class died out pretty quickly. I think the kilo record was about 95 mph. That puts it about at FEH speed.

There are a number of threads about them on www.screamandfly and www.boatracingfacts.com. A little on the Crescent/Volvo outboard history site too.

The motor was originally built as a 500cc alky and was competitive for a while, probably just before the 4 cylinder opposed Konig came out. This was 1963-67/68. The gas version was raced in Europe in their short lived Stock racing era before it became the CSSH class motor in the US ... "C" Super Stock ... "Super C" for short.

They had chrome plated aluminum cylinders ... no oversize boring - and the block layout was too tight to update the porting when the Konigs started to get the best of them. Over the years Crescent had at least 2 different ignitions on them, neither was 100% reliable and many were rigged up with Merc distributor ignition from the 3 cylinder 65 Merc.

[Blackhawkguy]

Thank's

what made me ask was a friend of mine was telling me they made a three carb manifold for the Merc 65 three cylinder and I wondered if this motor ran in that class, but you have answered that question for me.

Thanks Kerry

[sam]

Merc made 3 versions of the 3 carb triple. I think there is one on eBay right now.

One had a full gearshift lower unit and was sold as a sport/race version thru regular dealers. They sold 250+ of them for 3 or 4 years. The Merc 650 XS.

The other versions used Speedmaster lower units and came from Merc racing. These were the OPC Mod 50 class Merc 650X and 700X.

[Blackhawkguy]

Never thought of Mod 50

Thanks Sam, I guess I never thought of the Mod 50 class, always thought this was a OMC dominated class

Kerry

[sam]

Thanks Sam, I guess I never thought of the Mod 50 class, always thought this was a OMC dominated class

Kerry

You are right, it was.

[trident]

Merc triple racers, Mod 50

Sam is correct about the 3 carb Mercs.

But there is one more 3 holer Merc racer, even more rare...

Not based on the 'normal' 650 / 700 49.9 block, it was a 3 hole 50 ci. LOOPER, an all out Mod 50 motor, raced mainly in Europe (OE?). I believe they were Bendix fuel injected and there were only 5 or so ever built. Not an urban myth. I have seen one. It looks totally different. And, I know the difference. I have two 650XS' and had a 700X.

If you're referring to the 700X block on e-Bay, it is sold, auction is over. (It was mine).

Those 650/700 3 carb motors were a diecast block, but had special porting, etc., different from the production service motors and had a special sand cast matched 3 carb front end. Matched, in the same way other Mercs are finish machined as a block / crankcase cover assy. This is not some 'bolt-on' piece you can add to the service motors.

That's all nice... unfortunately, you guys are right. OMC dominated the class, pretty much.

[c-more]

Those 650/700 3 carb motors were a diecast block, but had special porting, etc., different from the production service motors and had a special sand cast matched 3 carb front end. Matched, in the same way other Mercs are finish machined as a block / crankcase cover assy. This is not some 'bolt-on' piece you can add to the service motors.
.

It just bummed me out reading trident's post. I was hoping to find a 650Xs front half somehow and upgrade in stages. I have a line on a 650X 12" mid. I planned to use a stock gearcase case and powerhead until I could find a SSM and XS front half (and XS porting specs). Sounds like the entire XS block is the only way...or is it? I read a post somewhere that referred to an experimental F.I. setup using half a V6 system ! ....but that probably was on the 3-carb front. Any other intake options out there. I know I could get a stinger75 and be faster/cheaper, but my steering wheel is black.

[johnsonm50]

About the time Dick started importing them, Volvo bought out Crescent and stopped making them and all the parts (there is no truth to the rumors that they are based on the Saab Sonnet car motor, nor that they were built by Volvo). Dick had to have some parts made in the US and scavenge ignition for them by the end; Volvo was not interested in keeping them in production just for US racers and - they were obsolete in Alky racing. With no new motors available and very high speeds being attained, the class died out pretty quickly. I think the kilo record was about 95 mph. That puts it about at FEH speed.

There are a number of threads about them on www.screamandfly and www.boatracingfacts.com. A little on the Crescent/Volvo outboard history site too.

The motor was originally built as a 500cc alky and was competitive for a while, probably just before the 4 cylinder opposed Konig came out. This was 1963-67/68. The gas version was raced in Europe in their short lived Stock racing era before it became the CSSH class motor in the US ... "C" Super Stock ... "Super C" for short.

They had chrome plated aluminum cylinders ... no oversize boring - and the block layout was too tight to update the porting when the Konigs started to get the best of them. Over the years Crescent had at least 2 different ignitions on them, neither was 100% reliable and many were rigged up with Merc distributor ignition from the 3 cylinder 65 Merc.

In the early 70s I worked after school at a dealer that had a few new Saab Sonnets, I even got to drive one around the lot a time or 2. Very cool - waaay ahead of its time & tiny as can be, 1300lbs I think. I dont remember it being a 2 stroke tho. Some older Saabs were, easy to spot the trail of blue smoke but not a very fast car as one might think it should be if it were the same as a Crescent.

[snyder]

I'm the guy that made the block and crankcase drawings for the special 3 hole 50 ci. LOOPER, under the direction of Fred Hauenstein back in the late 70's. That engine did beat the OMC's.

[sam]

I'm the guy that made the block and crankcase drawings for the special 3 hole 50 ci. LOOPER, under the direction of Fred Hauenstein back in the late 70's. That engine did beat the OMC's.

IN GERMANY as an 850cc OE class motor ... it was not raced in the US

Only a single prototype was released into the wild for testing, the motor was never produced in numbers, nor used as a cheater motor in Mod 50 by Merc team racers or privateers in the US.

[Team B&H]

To get back to Trident's comment on Marty Stahl. He did have a Crescent but it was the C Alky version, not the super C "Stock" motor. I saw it run a number of times and remember it being quick in the first but it hardly ever started for the second heat.

[Howie Nichols]

A few of the drivers I remember from New England that ran the Super C class back in the early 70's:

Pete Nichols
Bill Giles
Vinny Dubuc
Roger Hartwell
Brad Snow
Walt Hazlett

Obviously there are more but those are who I cna remember for now.

I have a 3 series pic of Dad blowing over the Super C in Dayton with what looked like a full field around him. '74 I think.