VAP

I've gotten a handful of emails requesting this info. The PS pulley and crank harmonic damper's pulley grooves are within a few 'thou' (thousandths of an inch) of being EXACTLY the same diameter. This means that the PS pulley virtually matches the engine RPM and not the cam's RPM which is half the engine RPM. So if you're tach shows your engine speed at 1k, 2k, 3k etc etc then thats exactly the same RPM your PS pulley is rotating or wihin 1/10 of 1% given your tach is calibrated correctly. So power steering pully and crank harmonic damper, at least on the 12V engine, are 1:1 ratio for ALL intents & purposes.

Disclaimer:
The above info is based on the 12V engine with OEM harmonic damper only and "may" not be applicable or accurate to the 12V or other engines using the same pulley but with different diameter OEM or aftermarket harmonic dampers.