Conversion to 8-rib serpentine system
Since upgrading the blower to the overdrive cog setup along with porting of the blower, heads and going to the LS7 MAF, I've had issues with the 6-rib serpentine belt shredding under harsh conditions such as road course events. After the second trip to VIR where my belt came apart, I decided it was time to go to an 8-rib setup. I did some research and found a couple companies that supplied kits to do this with the major pulleys (balancer, alternator, power steering) but I would still have to find the idlers and purchase the blower pulley. The cost of these kits is roughly $1500-1700 depending on supplier which is kind of high for me! Rick Crawford encouraged me to look for stock pulleys and try to do it myself. I decided to go this route and see what I could do. I did more research than I can remember, looking for pulleys that might work. Typically the inner diameter and width are published but with no information on bearing position front to back. The bottom line is that I wound up working with local auto parts stores to buy pulleys and try them out, return them, try others, return them, try others, etc. until I found the right combination that worked. I had to have a new balancer in any case and found one on e-bay from ATI that was a blemish that they were selling for half-price! They had a couple of them in case anyone else is interested in going this route. The blower pulley was ordered from Magnuson of course and I couldn't find a power steering pulley that worked so I ordered one from Innovators West. All the other parts are off the shelf, some require a washer behind them to get them to the right position and the lower idler had to be machined on the back as did the alternator pulley, but with some work, I saved a ton of money and have a successful 8-rib setup. I won't publish individual prices on the parts to respect forum policy, but the total cost at the end was $630, or a savings of about $900! Below are the parts I used along with a photo of the setup. One more thing: I wanted to use a Gates Fleetrunner Green belt and this was a little dicey. They only make one length that would work for me and it's pretty tough to get on! I have to get the belt on everything except the upper idler via relieving the tension via the tensioner, and, starting with the upper idler off its spindle with the belt under it, use a screwdriver through the idler ID, catch the ID of the spindle and leverage it on with the belt under it (kudos to Rick for figuring out the method!). It's a little tight but works well. I'll look at the possibility of relieving a little material on the tensioner stop to allow the tensioner a little more range at some point.
Balancer, 8-rib: ATI Super Damper 917345, (stock diameter, for Corvette)
Lower Idler: (between balancer and alternator) Dayco 89102, smooth, powdered metal, 46mm wide. Machined off ~5mm from the backside (the bearing is offset toward this side), used 1 washer behind.
Alternator pulley: Ford 208-14000, Wagner W055-25 machined roughly 5mm off the back of the pulley and boss on the alternator
Power Steering Pulley: Innovators West, part for the Corvette. Had to machine the ID as the press was too high, matched the stock one at 0.667/9 inches.
Upper idler (smooth, on blower): Dayco 89094, smooth, plastic, 74mm OD
Blower pulley, 8-rib: Magnuson 2.8in blower pulley
8-rib tensioner pulley: Dayco 89053, needs one washer behind it.
Belt, 8-rib, Green Stripe: Gates Fleetrunner K081035HD 104 inch length
8-rib belt photo.JPG
I'll be happy to answer any questions if you have any!
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Originally Posted by STL_G8GT
