i have a d15b7 with a d16y8 head and d16y8 head gasket. what should my compresion ratio be?

 

http://www.knology.net/~jediklc/D.htm

its supposed to be like at 10.5:1

 

ok, that helped, but how do i find out what i realy do have. i did a compression test and got: 198psi 198psi 200psi 200psi. how do i calculate what cr i realy have from these numbers?

 

you are talking about compression not compression ratio there is a difference. you cant get the cr for the compression test.

compression ratio: the ratio or the volume in the cylender above the piston when it is at bottom dead center tothe volume above the piston when it is at top dead center.

compression test: a test of the ability of the engine to compress air. the readings you get are of the amount of air per square inch that the engine was able to compress. if some of the readings are very high it might be because of a higher cr due to carbon build up. if they are low it is probably because of worn parts, head gasket, rings, valve seals, ect.

 

Compression test also measures how well the engine sucks in air. Amount of fluid affects pressure as well.

Valve seals are not a factor in the compression test.