turboal1

Ok, I have conflicting info on the OD of the crank pulley
on a late model 6.2 Silverado. 7.24 od or 7.72 od or are both
wrong ?

Atomic

iTrader: (42)

Measure from the top of the ribs, not the outside edge.

Blown06

iTrader: (32)

I assume you are asking this in regards to figuring out the rpm of an accessory driven off the crank pulley. If so, knowing the actual diameter or circumference is not needed. Due to the fact that accessory rpm is proportional to or a ratio of the two pulleys (the drive pulley being the crank and the accessory pulley being a blower pulley for example), all you need to do is just be able to measure them in the exact same way and then calculate. Understand?

For example, say my measuring stick says the crank pulley is 8" and the accessory pulley is 4", when the motor is at 8000 rpm, the accessory is at 16000 rpm. Now you get your measuring stick out and say "no your wrong, the crank pulley is 6" and the accessory pulley is 3"..........it really doesn't matter because your 6":3" ratio is still going to produce an accessory speed of 16000 rpm at an engine speed of 8000 rpm.

If the information I typed above has absolutely nothing to do with your question, sorry and just ignore this post.

old motorhead

iTrader: (10)

7.5 inches.

turboal1

Motorhead, is that an actual measurement ?

old motorhead

iTrader: (10)

I can't say they're all 7.5". The ones I've checked were though. And a 10% o/d pulley measures 8.25". I've checked that one too. I have seen 10% o/d crank pulleys being sold that state that they're 8". That would mean the stock one on that motor would have to be +/- 7.25" All I can say is......go figure.