[ChrisBennet]

Tomorrow I'm helping someone figure out what he's purchased for a motor. It's supposedly a 2.8 that used to have carbs. I've got a plan for determining the cam but I'd like a way to figure out the compression and displacement without filling it full of liquid.
I think race tech inspectors have some way of doing this but I don't know how.
Here are some crazy ideas I have:
(A) Measure displacement by measuring the volume of air displaced on the compression stroke. I'm thinking a "U" shaped tube partially filled with water plumbed into the spark plug hole such that air in the tube would force water out the other end of the U tube. I could then catch and measure the water displaced.
(B) Measure compression by measuring the difference in TDC/BDC air pressure with a manometer. I'm thinking the air might leak out too fast for this to be practical even with a little oil to help things seal.
Any ideas?
thanks,
Chris