Hey guys I just did a compression test on my b17 today and got 210psi on all four cylnders. I was happy to see all four the same. I did it when the engine was cold. Correct me if i am wrong but a cold engine will show higher compression correct?

 

Does anyone know if this is normal for a cold engine?

 

that's great! good numbers. consistency across the cylinders is more important than how high the numbers are, but 210psi is nice. must be in pretty darn good shape! and yes, doing it while the engine is warm will yield higher numbers, but leave the spark plugs out until the engine cools. torquing the spark plugs in while the engine is warm will result in having the wrong torque. the torque of 13ft*lbs is for engine cold; i don't know what it should be at operating temperature. i don't use a torque wrench fo suspension and brakes because i'm very good at feeling the elastic to plastic deformation point, but in the engine i ALWAYS use my craftsman torque wrench. only the best, because engines parts are high stress and run at large temperature variances.

 

great response thanks man. I did not tourque my spark plugs down with a tourque wrench due to the lack of owning one. I just tightened them to where it felt good. I might buy some new ones today. Yes i was pleased to see all cylnders the same across the board. I did it a few times on each cylnder and got the same results every time.

 

yup, you're supposed to let it crank 7 times for each test, then release and move on to the next one or release and recheck that one. just 7 times though. i know if i let my LS crank to 15 times it will probably go above 200, and that's REALLY not normal for 9.2:1 c/r motor. 210psi is still fairly impressive for a motor with 10:1 c/r.

 

I think my motor has like 9.2:1 I let it only crank 7 times. But anyways If my compression results are good could my piston rings be bad?>

 

Dude you have prettt good numbers there. I would not worry too much other wise.

 

well I am losing oil, At least I think I might be. I got my oil changed and never really botehred to check on it then one day was working on my car and checked had little oil so I added some like a week ago and am checking it everyday. I am worried i might be burning it but i got great compression results.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Teglessb18 &raquo;</TD></TR><TR><TD CLASS="quote">I think my motor has like 9.2:1 I let it only crank 7 times. But anyways If my compression results are good could my piston rings be bad?&gt; </TD></TR></TABLE>
huh, i just checked and B17 has 9.36:1. no wonder it doesn't make that much power . . . i always figured Honda would give their third production VTEC motor higher compression like their first two.

 

Oh where it lacks in power it makes up for in that short geared transmission