Interest in new 3 cylinder drag rules..motor alterations and mixing manufacture parts

[Hounddog]

The 49 Yamaha would be interesting to build. The CES does not share the 40/50 gearcase, it has the 55 case. Making a 3 cylinder SST45 could be possible. I have seen mod 4 cylinder motors in snowmobiles made from two 2 cylinder motors. Years ago some mod outboard racers mounted 2 powerheads on a single tower.

[Powerabout]

It would mean making new 3 cyl crank and see if you could swing that in 56 case?
Thats the engine omc should have made as yam just marched in with bigger tripples and took tons of market

[Hounddog]

Based on the 56 OMC engine builds here in Canada a good drag motor would be oval port sleeves in a 1986 production cast block, mod 50 flywheel, Kevi baseplate and tuner, SST 60 gearcase with hooper billet carrier and 2 cylinder gears, a 12 1/2 X 24 thru hub Hill prop on a 13 foot Allison. Tuff to beat in 600 feet.

[filthy phill]

so you would put oval port sleeves in a bridgeport block .

what will you do about the the alloy bridge cast into the block itself. this would be visible with no sleeves in the block .(according to other on this site)...
would you cut this wall of alloy out the block or leave it in.

and why the cast block instead of the lost foam block, they are identical inside apart from a few glue lines, apart from the later cooling modifications made to the oval port block.

what would be the benefit in changing blocks ?
and the 2 cylinder gears being what ratio ? 2.42 or 1.86

[Hounddog]

so you would put oval port sleeves in a bridgeport block .

what will you do about the the alloy bridge cast into the block itself. this would be visible with no sleeves in the block .(according to other on this site)...
would you cut this wall of alloy out the block or leave it in.

and why the cast block instead of the lost foam block, they are identical inside apart from a few glue lines, apart from the later cooling modifications made to the oval port block.

what would be the benefit in changing blocks ?
and the 2 cylinder gears being what ratio ? 2.42 or 1.86

I would clean up the block and remove the bridge casting. The production block flows air better that the foam cast and even with the cooling mod to the foam cast, the production block is better. My thinking behind using the 2:42 gears is about hole shot, acceleration and 600 feet. The oval port motors running here have a big torque, low and mid range advantage over the bridge ports. A big diameter, big pitch prop turning slower will get out of the hole and accelerate faster with the 2:42 gears. You may need to repitch the 24 to 26 but if the motor is turn over 8000 for a second or two, it does not matter. Drag is about ET for 600 feet not speed reached at 600 feet. Only my opinion.

[filthy phill]

600 feet ? do you mean yards.

600 feet is just 200 yards
if its feet how long does it take for this race to be over ?

[Hounddog]

600 feet ? do you mean yards.

600 feet is just 200 yards
if its feet how long does it take for this race to be over ?

Their current rules posted on this site have the distance at 660 feet.

[Ron Hill]

It would mean making new 3 cyl crank and see if you could swing that in 56 case?
Thats the engine OMC should have made as yam just marched in with bigger triples and took tons of market

I quote you, Powerabout, and I'm not sure you said it. But if OMC would have continued to make two stokes and sold them worldwide, (Meaning outside the USA) they'd never have gone broke. I think you said that to me on the phone one day.

Seems, as I recall, my brother, asked Charlie Strang, why the 49 cubic incher was the way it was? And the answer wasn't what my expected. The answer was the NEW $100,000 mill wasn't large enough......It something that!!! My brother said, "Really?"

Too bad, you didn't "Take Over" OMC, Powerabout. You could have made OMC Great........I'm not sure I'll use the word "AGAIN".

I'd argue with you abut Yamaha. They took the WHOLE MARKET.