Oversized Pulley, Custom
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Rand
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.
Here is an old report of my custom pulley with
some good pictures.
For merely $213, a ring,
made of tool-steel, was pressed over the stock pulley. The three set screws are 120 degrees of each
other. I did not get this pulley re-balanced.
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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!
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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!
| Notice just how much the belt is going to be rapped around the clutch
pulley once the idler pulley is tightened! Engine is not ready *notice no timing belt, crank
pulley is not bolted up* With the idler pulley tightened, it is almost 1 1/4 inches higher than
pictured. This causes the belt to rap up underneath the Supercharger clutch pulley. |
Numbers
With 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!