Originally Posted by Patrick Feeley
I'm not seeing why you would need to measure something like that on our engines. The cylinders (or pistons) don't rotate, so their rotational velocity should always be zero. The linear velocity of the pistons would be related (for the most part) to engine RPM. Cheers!
My understanding is that it is the amount of change the crank see with the fire of each cylinder. So if you have like 1%on seven cylinders and like 5% on one that would say there is a problem to be addressed in that cylinder (injector,low compression and so on)