308 double pulley

jjnan58yahoocom

what gm water pump pulley do you use with a back set dim of 1.600 ? Thanks

DavidC

I used a standard Chevy SB SWP double pulley, reverse mounted on a machined stock crankshaft pulley.  The matching WP pulley came from CVF Racing, SBCL1WP.  It needed slight modification of bolt holes to fit, a standard spacer kit gave me perfect alignment.  You need to match the diameters of your pulleys so the accessory RPMs are correct.

jjnan58yahoocom

it looks like a 63/16 dia. wp pulley with a 2" plus setback will hit the water pump intake?

DavidC

Attached is my belt routing and both pulleys installed. I had no clearance problem with WP. But, as you can see from the pic, there is no WP shaft protruding through the pulley to engage the fan. You either have to go to electric fan, get longer WP shaft, or do what I did: insert bushing that locates fan and is retained by band of metal on fan.

DavidC

Here's a pic with fan installed. Under that metal strip is a bushing designed to align fan with shaft of WP. Works perfectly, no vibration or shake, but a longer WP shaft would be even better- maybe next time.

DavidC

Also, please note the harmonic balancer is still fully functional; the chrome double pulley is mounted only to the outer part of the pulley, with bolts that do not reach the rubber disc. The dampener-crankshaft bolt and washer install as usual, and there is not contact between pulley and bolt. This took a lot of work at my local machine shop, but now that it is done I feel it is worth it; I can get new belts and pulleys from anywhere.

jjnan58yahoocom

I am doing something similar but with power steering. Is the mounting bracket on your setup 11ga? I have the crank pulley completed and now to tackle the rest. Your setup looks very good.

My conversion is on a Hornet engine with a 5 speed in a 46 pickup.

DavidC

I believe the mounting bracket was 3/16 steel

RL Chilton

I have one, too.  I think it's 1/4".  It's really stout.  

DavidC

Russell's correct- 1/4 in