Did a comression test earlier today and found the numbers to be much higher than I've seen posted on this board. On pistons 1,2,3,4 I got 260, 255, 255,260 respectively. I got these numbers after unplugging the ecu fuse and cranking each cylinder over 7 cranks with the throttle wide open. This was after driving around town and letting the engine cool down for like 30 mins. Its a stock, afaik, '96 GSR with 106k on the odo. Aren't these numbers a little high? Or, does this just mean that I've got good ring seal??

 

Nobody has a comment on this?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by br1ev8 &raquo;</TD></TR><TR><TD CLASS="quote">Nobody has a comment on this?</TD></TR></TABLE>

7 cranks is a little much. I mean, you can crank it all day and get "good" high numbers. You prolly have carbon build up which will in turn raise the numbers. Its not so much that the numbers are "high" that is desirable... its more consitency that you look for when doing a compression test. Gauges always will vary.

 

I wouldnt worry about it. Like that kid said, you want consistency, gauges vary. When I did mine on my stock JDM b16a, I got 240 across the board. CSpeed Racings website said they got 250psi across the board on their race motor w/ 11.5:1. I was paranoid too, but the pressure will vary from gauge to gauge. I find it hard to believe that carbon buildup could raise your CR more than a whole point...

 

I've always read and heard that 7 cranks is proper.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ccivic &raquo;</TD></TR><TR><TD CLASS="quote">I've always read and heard that 7 cranks is proper.</TD></TR></TABLE>

You can crank till the cows come home if you like. As I mentioned, peak numbers are not what makes a compression test usefull. Everyone seems to get caught up in them though as if it means they have a "freak" motor or something. The numbers are clearly not low and they are consistant. These are the only two things anyone should be concerned with those results.

 

did you pull all the plugs?

 

Yeah, I pulled all the plugs before doing any one of the cylinders. I did 7 cranks because that's what the manual says to do, not because I was going for "peak" numbers, or any other bs. I did what was instructed for the procedure and the numbers I got are higher than I've seen posted. I was simply concerned.