hello everyone. tomorrow, i plan on doing a little compression test just to see how the engine is holding up. i was wanting to know what numbers should be expected for a 1992 Integra GSR… thanks a lot and have a nice day. :rockon:
I don’t know off hand but I will take an educated guess to at least get you a bump because no one else is resonding. Here you go. Since you are in Houston I figure that is close to sea level so we will start with ambient pressure @ 14 PSI times the compression ratio of 9.2 will give you 128.8 PSI, so I would say between 110-120 PSI. This would make sense to me, but I have never tested my compression. I also think it wouldn’t be good to have any cylinders out of the 10% range of each other. Any one else care to jump in? I know I should tell you to search but I am not a pyro and don’t like to light people up.
If your compression turns out to be around 110-120 you got a serious problem. It should be upwards of 200-210 psi. My JDM LS was 210-195-200-195. HTH
Chris
Correct
normal : 184
minimum : 135
max variation between cylinders : 28
Took it from my Haynes so it cannot be wrong.
Right on, I was just venturing a guess. But I guess I look like I don’t have a clue. How is it that you end up with PSI that high? I figured that you would just take ambient air pressure and multiply by your C.R. I don’t get it :wtf: , someone please explain the physics behind this to me. Thanks.
I don’t know the physics behind compression ratios, and this is purely out of my pethetic memory, but I do know that there is Static compression and Dynamic compression. And more radical cams actually bring the dynamic compression ratio down I believe. Also, the B18A1 has 9.2-1 static compression and the B17A has 9.7-1 static compression, but their corresponding dynamic compression when tested with a gauge is almost identical, in fact the B18A1 should be one point higher for Nominal compression.
Nominal (optimal) dynamic compression for the B17A is 184 psi and for the B18A1 185 psi, and Minimum dynamic compression being 135 for each. Isn’t it weird that the higher static compression B17A engine would have a lower dynamic compression compared to the B18A1 when tested with a gauge. High lift and long duration cams with overlap cause the dynamic compression to go down.
I might have the terminology of static and dynamic wrong, so I would hope some of the Guru’s could chime in and set me straight. I truely hope I got some of this right tho, just food for thought.
thanks everyone for their input about this… :salute:
Anybody have some answers to my questions?