Can someone with a degree pulley or similar go out and measure how far to the left the 5 deg ATDC mark should be from TDC? I have a chrome stock style EMPI pulley on my car and can't find 5 degrees.
When I time, the 5 degree mark should line up with the case halves, right?
TIA,
Rob in Salt Lake
It will depend on the diameter of the pulley. I'd just go out and measure one of mine for you, but none of them are here at the moment. Unless someone jumps in with a distance, here's how to figure it yourself:
Get a calculator and a measure tape. carefully measure across the pulley to get the diameter, and multiply by 3.1416 (pi) to get the circumference of the pulley. Divide that number by 360 to get the distance around the rim of the pulley that equals one degree. Multiply that by 5 and that will be the distance of 5 degrees from the TDC mark. For example:
8" diameter pulley 8 X 3.1416 = 25.1328 25.1328 / 360 = .0698 .0698 * 5 = .349"So for an 8" pulley, 5 degrees would be .349", or just over 11/32" around the rim of the pulley. And yeah, the case seam is the timing reference.
Cheers, Walt
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