3100SFI plans...

[toddshotrods]

Five
Does anyone make an aftermarket/performance harmonic balancer for these motors? What are the people who twist these to high revs using?

Six
Anyone know the exact distance (center to center) from crankshaft to camshaft? Thinking about a Jesel style belt drive, and want to see if I can find the right combination of pulleys and belt.

[Guest]

Five
Does anyone make an aftermarket/performance harmonic balancer for these motors? What are the people who twist these to high revs using?

Nothing is available.....
I will however be looking at using a SBC balencer on mine in the future. The crank snout diameter is teh same size along with the woodruf key.

Six
Anyone know the exact distance (center to center) from crankshaft to camshaft? Thinking about a Jesel style belt drive, and want to see if I can find the right combination of pulleys and belt.

Good luck with that, I've been trying to find info on the Jesel (or even other belt drives) for a while now, to make the same modification.

On GenI and II 660s the camshaft uses the same bolt pattern as a SBC, but uses a much smaller pulley. A SBC pulley is about as large in diameter as where the front cover mating surface is, so this makes it difficult to contain the belt drive.
The crank snout again, is the same size and whatnot as a SBC, so the crank drive pulley can also be used from a SBC set, but the distance between the center lines is much greater. IIRC, it was about 6.5" ceneter to ceneter, where as I believe the SBC was only about 5.25"

[toddshotrods]

Nice tip on the SBC damper, that would solve that problem. As long as the crank diameter and key are the same I should be able to make that work. Fluidampr has a lightweight race damper that would be perfect for what I have planned.

For the belt drive: Using a 22.5x1x3/8" pitch Gilmer belt, with a 16T crank pulley and 32 tooth pulley on the cam would give a center-to-center distance of 6.68". An idler pulley could be used to take up the slack. I got all this from the Stef's Fabrication Specialties catalog. The website doesn't have much info but their catalog is a bit better. The 32-tooth pulley I referred to is a dry sump pump pulley so a custom center would have to be machined, and bolted or welded in, to fit it to the cam and align it with the crank pulley. The crank pulley should fit because it would be standard SBC stuff.

I am planning on having a custom plate machined to replace the front cover, which will leave my belt drive out in the open. Someone attempting this with the stock cover would have to check for clearance with the 1-inch belt and pulleys. I am going to call tomorrow to price the pulleys and belt, and to see what the diameter of the 32T pulley is.

Looking on the Jesel site, their cam pulley is a multi-piece deal anyway. A lot of their parts could probably be used with the 32T pulley and custom center to avoid recreating the wheel.

[geoffinbc]

If you go with the belt drive what are you going to do about the water pump?

[toddshotrods]

Remote electric water pump. Remember, it's a race car with plates and lights, doesn't have to be practical...

[geoffinbc]

Cool.