hello, i just did a compression test on my ls/vtec right after my valve adjustment
left to right as follows:
190
200
205
220

i have a 12:1 ls/vtec with usdm type r pistons, total seal rings , and 0.40 taken off the head with skunk stage 2 cams.. the motor only has 2000 miles and i dynoed it at 185 whp corrected #'s, 192 un corrected.. the machine shop that built my motor is telling me that those compression #s are fine for those cams.. is this tru?? i think they know its a piston ring sealing problem but just dont want to admit it.. i hope its not the rings tho!! what do you guys think?? tia

 

No, the cams will not effect your compression numbers.

 

185whp with the mods you have is very low.... im guessing you should be at least around 200whp and with a 12.1 overall compression im pretty sure you should higher numbers then 200.

 

ihave an ls/vtec with usdm itr pistons and 30 milled off the head and my compression is 290psi..so something is wrong with yours.

 

you have the compression of a strong GSR

 

cams can alter compression readings. Cams with alot of overlap can make the readings lower. Cam gear settings can also effect compression numbers. What you might want to do is adjust the cam gears to decrease overlap and redo the compression test and see if you numbers go up. Follow up with a leakdown test or at least a wet comp test.

 

This dude is right. If both valves are open at the same time for very long you will not make as much pressure. Dynamic compression i think...

Those look like nice numbers for an old b16.

 

my b16 reads roughly 200 across..its a 1stgen b16 88-91 just incase that helps

 

AGREE, and bailhatch you are correct... this is dynamic compression... I would go about it just as hybrid_KJ said... pull some overlap then if you don't notice much of a change run a leakdown test... SK2ST2+ cams generate a fair amount of overlap even at 0-0, this is why they are suggested for "higher" compression motors... I wouldn't use them with anything less that 11.5:1... Good Luck...