bad compresion
 

i just got a 93 prelude with a f22a1 motor cylinder 1 180 psi cylinder 2 120 psi 3 180 4 180 so im 50 psi down on one cylinder oil looks ok. is it a head gasket problem or am i screwed? there is a crappy turbo on it with shattered manifold on cylinder 4. is this a complete egine rebuild ? or am i missing somthing?

RE: bad compresion
 

welcome to the forum, you have a weak cylinder, it is not a gasket problem, if it was, you would see signs of water in the oil = creamy oil color, bubbles or lots of air in the radiator system. it could be a dirty valve causing you to have a low pressure. If there is a way for you to do a leak down check,(like in a/c piston engines) piston at top dead center, prevent crank from turning, add approx 60-80 psi of air through the spark plug hole and listen for the air leak, if crank case, your piston rings are leaking, if intake, or exhaust, the valve is leaking. becareful if you do the leak down test.