compression check.

my boost gauge ever sence i got it has been showing me idleing at 10 vac and 15 while crusing. i finally got around to doing a compression check on my 96 gsx. looks like bad news. this is what it was through all 4 cylinders

http://files.automotiveforums.com/gallery/watermark.php?file=/503/156077compression.jpg

im not really sure what this means. the car still runs preatty well, no misfiring, no stalling, smooth acceleration but its defnitly not fast!!. what needs to be done to get the compression back to 180 range?

133 psi is the service limit, I guess you're getting there. Time for new rings maybe?

either rebuild it or drop in a six bolt. you might want to do a leakdown test and figure out where its leaking from. this will tell you if its the rings, the HG, or a valve not closing completly.

you can also do a dry and wet compression test. do it dry first then pour a shot of oil down each spark plug hole and see how much the reading goes up. if it goes up a lot then its probably your rings

i'll do a wet compression check in the next couple days to see if its my rings! thanks.

I would'nt suggest pouring oil in there, a tablespoon or two should do. are you holding your throttle open while you check compression? you need to use a screwdriver or something to hold it open while you test. Dude is right, if you do the wet test and compression goes up. time for new rings.

hey your psi reading is in blue. seems to me your registering 140 psi in all cylinders which is good. dont fuck with it. You might be reading the wrong dial.

Yes he is getting 140 to each cylinder but 140 = Good? WTF are you smoking? That is far from "Good"!

well. i finanly got around to doing a wet compression check on the old beast. i did this morning after letting it sit overnight. im not sure if that makes any diffrence. but here is what i got

New Wet: 162-172-160-164
Month ago dry: 140-141-141-140

so. not sure what to do next. i was expecting the compression to be higher then 160+ when i did the wet check. if it was solely the rings would the compression be higer? any suggestions?

those numbers basically say your rings are getting pretty wore out. it's either time to give that beast a re-build or just drop a damn 6-bolt in it and really haul some ass. a wet compression test won't seal them up like brand new, but it will give them a little better seal, that's why the numbers go up...but not by like 40 points.

yeah, i have a 6bolt in my garage i need to get working on. i doubt it will be ready to drop in by this winter. who knows.

currious. how far can i take the motar the way it is? would i beable to run mid/low 13's with such low compression??

i wouldn't try it. just re-build it before you really fuck something up.