C2 clutch pivot

[frank mccracken]

I'm putting together a sb400 for my '65. The clutch pivot boss holes in the block are not drilled and tapped. Can some one tell me what thread size the hole is so I can fix that up while it's on the stand? Also, does anyone happen to know, the crank pulley seems to have a weight on it. Can anyone tell me if that needs to be oriented in relation to the keyway?

[Joe L.]

Re: C2 clutch pivot

Frank------

The clutch cross shaft engine side ball stud is 7/16-14 thread size.

I am unaware of any weight used on the crank pulley. 400 small blocks are externally balanced, so they use a counterweighted harmonic balancer and a counterweighted flywheel/flexplate. The keyway on the balancer ensures that the balancer will be installed in the correct orientation. The dowel pin on the crankshaft ensures that the flywheel/flexplate will be installed correctly.

I don't know why there would be any offset weight on the pulley unless it's some sort of aftermarket device to allow the use of a non-counterweighted balancer on a 400 engine. I wouldn't dream of using such a "solution". If that's the deal here, I'd get a correct 400 balancer and forget any "add-on" weights.

[frank mccracken]

Re: C2 clutch pivot

Thanks Joe.
I'm familiar with the external balancing on the 400sb. I do have the correct balancer and flywheel but on re-assembly I'm noticing a bit of a weight on the front pulley and am wondering if it's something I haven't noticed or heard of before.

[John H.]

Re: C2 clutch pivot

Scoggin-Dickey sells a bolt-on adapter bracket for about $60 to mount the clutch shaft ball on later blocks; eliminates having to drill/tap the block.

[frank mccracken]

Thanks John *NM*

[Michael H.]

Re: C2 clutch pivot

Since you're not concerned about originality, check out the article I wrote in the recent issue (April 2004) of "Corvette Enthusiast" magazine on converting from mechanical clutch linkage to hydraulic clutch release bearing. You can eliminate all the cross bars, springs, bosses, etc. and free up a lot of space in the engine bay. If you'd like, I can send you a copy of the article in Adobe format if you provide me with your e-mail address.

Mike

[frank mccracken]

Re: C2 clutch pivot

Thanks Mike but I prefer my mechanical clutch actuation. I've always found hydraulic clutch controls to be a little slow reacting when you're in a "hurry"