Hey, I just ran a compression test on my car this weekend, and what I came up with was not quite what I would have thought.

I have a 95 Civic EX with the stock D16Z6, only engine mods are a CAI/H/E, plus B&M FPR. The engine has 192k miles. I would have expected somewhat low numbers, but here's what I came up with:

Cylinder #1- 196psi
Cylinder #2- 200psi
Cylinder #3- 195psi
Cylinder #4- 205psi

According to the Haynes manual nominal is 186psi if I'm not mistaken, with a maximum variance between cylinders of like 26psi (I think, don't have book with me).
I would have thought that due to ring wear on such a high-mileage motor, I'd have lower than average #s, but definently not the case. I took the reading after turning the engine over through about 7 rotations.

Did I screw up something when doing the comp. test, or does anyone have any explanation as to why the #s came out so high? The engine appears to run great, idles smooth as glass, and was good for a 15.7 @ 87mph (not exactly breathtaking, but not too bad for a lightly modified "D" in a heavy assed EX coupe IMHO). The way I see it, if it ain't broke, don't fix it, but if anyone has any suggestion why the comp. test numbers came out so high, I sure would appreciate your input. TIA.

Chris

 

Did you disconnect the injectors? Fuel will increase comp.

 

I pulled the plug off of the fuel pump.

 

Those look real good. Plenty of life left in that motor.

-edit- The numbers might be higher due to your compression tester. I have used different brands on my motor and the results always differ. Just look for consistency.

 

OK, well thanks for the input. I plan on swapping when this engine gives up the ghost, but until then, if it ain't broke,..... etc etc.

Thanks again everyone

 

you make me mad...

my d16z6 came up with 135-125-145-170...lol

and it was still good for a 15.5

I say leave it as a good running engine

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Emerika &raquo;</TD></TR><TR><TD CLASS="quote">you make me mad...

my d16z6 came up with 135-125-145-170...lol

and it was still good for a 15.5

I say leave it as a good running engine </TD></TR></TABLE>

LOL, that's actually more along the lines of what I was expecting .

Yeah, I'm going to swap when it gives up the ghost, but in the mean time I guess there's no sense in junking a perfectly good motor (that's just throwing money away IMO).
I thought about SOHC turbo for a while, but I'd really rather not boost this motor, not with as high a mileage as it has. Perhaps a baby (35 shot) of giggle gas just for some fun at the 1320.

Oh, and that's a pretty good time BTW . I was actually expecting slightly quicker, but had a hell of a time hooking up at the track I ran at (Costal Plains Raceway in Jacksonville NC for those who are from NC). My 60ft times are usually 2.2-2.3, not exactly stellar, but at that track they were more like 2.3-2.5 . (One theory I heard is because it's virtually in a swamp, the humidity is perpetually high and makes the track a little slick, although I'm not too proud to admit it might just as well have been my driving ).

Thanks again everyone! Honda-tech is the greatest website!!

 

we checked the comp ratio in out z6 that we race about ever other week and spray a 75 shot on and the compression is 175 to 180 all the way accross...and it has about 165,000 miles on it...so your doing great...
BTW this car runs 13.3 with the 75 shot, 57300 zex cam and valve springs...

 

LOL here is something my 94 civic ex D16z6 has a massive 211,000 miles on it and I did a compression test on it today and it came out to a tight 211-210-220-205 now that is tight and I know my compression tester is good I have used it on all my cars. Honda’s run forever!! And one more thing seeing how I have all the parts will the HF manifold & DSM turbo thing work with a D16z6 motor??

 

Yes it will work
http://www.homemadeturbo.com

 

was test done when the motor was cold, warm or hot?

 

Warm, not really hot though. I didn't want to pull the plugs (and risk breaking one due to thermal expansion) until the car had cooled somewhat...

 

you shouldnt worry about damaging plugs. i pull mine all the time......like once a day after i do hard runs........

 

that's pretty good numbers since my d16z6 averages only 190 psi. considering my engine is at 136k and your is at 192k I'm jealous.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dirtySOHC's &raquo;</TD></TR><TR><TD CLASS="quote">you shouldnt worry about damaging plugs. i pull mine all the time......like once a day after i do hard runs........</TD></TR></TABLE>

That's cool, I guess I'm just a bit paranoid...it's just that I don't exactly relish the thought of driving to a machine shop on 3 cylinders

Thanks once again for everyones help!

Chris