It's called P&Ging, almost all rounde round tracks have the tester, because of limited rules in each class on compitation. In thew old days at AHRA,NHRA,IHRA that's how they used to check after a win or if protested. I can't remember how many times i got P&G'ed when running a blown/b/gasser.
Here's what the tester looks like, and if you know someone who is a tech at a sprint car track he may can test your engine for you. You have to disable the valves/remove puhrods on the cylinder being tested and remove all spark plugs. They normally roll the dice to see which cylinder will be tested, that being because a lot of the guys in the old days use to build an engine with one side bored bigger than the other.
They are not cheap, but here's the website to when they sell them
Zip.
http://www.precisionmeasure.com/test1.htm