230 psi compression odd for a b16a2 ?

[Mike_995]

Just did a compression test on my freshly swapped b16a2. Supposedly out of a 2000 sir civic from florida, with 80 000km's on the motor. The compression regestered at 230 psi across the board, being shocked I did the test 2x, and still got the same results. Is it a possibility that the original owner swaped in b16b pistons ?, because 230 seems way to high. Test was done at optimum running temp, throttle wide open, and injectors unplugged. I was thinking of going stock b16 turbo, but that compression seems a little high for turbo. It would probably be quite hard to tune against detonation. What do you guys think ?, b16b pistons ? turbo capabilities ?? If not im just going fully built lsvtec turbo.

 

[boostin4fun]

I looked in my hayne's repair manual and it said for the 2000 civic si that standard compression should be around 184 psi. I would double check that with a factory service manual just to be sure. So there is chance that you have different pistons or the head was milled. If you are planning on boost you should invest in some ARP headstuds. When you pull the head you can confirm if the pistons are different or not and at that point you could get a cometic headgasket to lower compression if needed. Or you can always just build the bottom end.

 

[Mike_995]

Ooo, yea ive been looking around and found around 190 psi is the norm. If there are infact b16b pistons in it there may be some hidden hp waiting to be unleashed, because I am just running a USDM b16a2 map. Im almost concidering throwing in my stg2 blueprint cams, supertech springs and retainers from my blown up lsvtec setup. Displacement and compression was a problem, but seeing the 230 psi mark I think that should be enough compression to yeild good gains with the cams.

 

[boostin4fun]

Yeah you will definetly get some good power gains with that compression with some cams and some tuning. You said your compression was really even across the board so that tells you your bottom end is still in pretty good shape. If you have a healthy motor you might as well get some use out of it for awhile especially if you have parts laying around already that will get you some decent gains.

 

[anonymoususer]

230 psi is a lot! way too high for a turbo- you're in the 11:1 comp range. cams, free flowing intake and wide open exhaust will make that thing scream. get a computer and tune it on the dyno- you'll be glad you did