cylinder compression b20b

[B20PWR]

I cant seem to find what my 99 b20b cyclinder compression should be.. last time i tested it it read 185 across when it was stock. now im b20v with a b16 head oem head gasket. iwanted to retest it and see where shes at now.. anyone know wat it should be or have a link thx.

[90.DB1.TEG]

not sure im gettin 240-250 but im high compression

[DarkAngel]

What are your numbers? Post them up.

[B20PWR]

Im seeing (4) 160 (3) 170 (2) 170 (1) 170 pretty obvious the numbers went down for some reason idk why. Btw i have the "high compression" b20

[Dead Bird]

my stock 9:1 b20b4 block with b16 head tested @ 191;193;192;194

[cbaracing]

you do realize compression test numbers have no correlation to what the compression of the engine is

when doing an engine compression test as long as the numbers have a variance of not greater than 5-10lbs per cylinder you have a healthy engine

170-170-170-160 = good
170-120-140-160= bad

[Dead Bird]

so a 12:1 compression piston isn't going to test higher than a 9:1 compression if both are equally healthy?

[cbaracing]

so a 12:1 compression piston isn't going to test higher than a 9:1 compression if both are equally healthy?

ok maybe i shouldnt have said no correlation at all lets just say compression test numbers are not an end all be all

ive seen stock b16s in the 170/160 range and the 200/210 range
those numbers were on healthy driving engines

there are many variables too for compression tests
thats why you dont read that much into it other than the 5-10lbs between cylinders

rings not gapped properly. valves sticking open. cam profiles. shitty compression tester used. shitty user using the compression tester. cranking the enigne 3 times instead of 5 to get compression reading. cranking a cold vs hot engine. cranking an engine that you put oil in the cylinders. testing an engine with a blown HG. testing an engine with a leaking HG. all of the above are going to yeild varying compression tests

[I Hate Import Cars]

ok maybe i shouldnt have said no correlation at all lets just say compression test numbers are not an end all be all

ive seen stock b16s in the 170/160 range and the 200/210 range
those numbers were on healthy driving engines

there are many variables too for compression tests
thats why you dont read that much into it other than the 5-10lbs between cylinders

rings not gapped properly. valves sticking open. cam profiles. shitty compression tester used. shitty user using the compression tester. cranking the enigne 3 times instead of 5 to get compression reading. cranking a cold vs hot engine. cranking an engine that you put oil in the cylinders. testing an engine with a blown HG. testing an engine with a leaking HG. all of the above are going to yeild varying compression tests

x2. All things equal (like that ever happens), the higher the static compression ratio is, the higher the compression numbers should theoretically be. However like Chris said, there are about a million variables that come into play to make the final compression numbers for a motor. Just because the numbers are lower than a similar motor doesn't mean there's a problem. Ring wear, valve sealing, head gasket sealing, cam overlap, engine temp, number of revolutions it was cranked, weather the throttle was open on all tests, etc. all have an effect on it. There's no "this is what it should read" when you're working with anything other than a BONE STOCK motor. As long as the variance between cylinders is minimal, you should be just fine.

[B20PWR]

x2. All things equal (like that ever happens), the higher the static compression ratio is, the higher the compression numbers should theoretically be. However like Chris said, there are about a million variables that come into play to make the final compression numbers for a motor. Just because the numbers are lower than a similar motor doesn't mean there's a problem. Ring wear, valve sealing, head gasket sealing, cam overlap, engine temp, number of revolutions it was cranked, weather the throttle was open on all tests, etc. all have an effect on it. There's no "this is what it should read" when you're working with anything other than a BONE STOCK motor. As long as the variance between cylinders is minimal, you should be just fine.
ok now i understand clearly on how that should be taken to thought. great info guys thx for the tech support. i was confused on all the dif types of readings people wwere getting but now i see it can very in diff motors, it just shows how healthy they all are..