Oversized Pulley, Custom
Machine Works, a local machine shop here in Fresno, California, told me that it would be cheapest
to have a ring built that is 170mm overall with about a 140mm center pressed over our stock pulley
after it has been machined down for a flat fit.
So just where did I end up finding an idler pulley as small as this one? Don't look now, but you already own one!
If you guessed Timing Belt Idler Pulley then you are correct!
Just order a timing belt idler pulley, flip it backwards, make a spacer, and wa-la! What a concept!
NumbersWith this pulley setup on my SC12, it is pushing 12 psi boost @ 70 degrees F, and 13.5 psi @ 110 degrees F.
Not bad considering my valves are pushed lower and opened longer with my racing cams!