i did another compression test today...here are the numbers:

~All test were done at WOT with the injector plugs unplugged and motor warmed up to normal operating temp (Type S)~

Cylinder #1:189 psi
Cylinder #2: 185 psi
Cylinder #3: 180 psi
Cylinder #4: 195 psi

Side note, this is the second compression test i've done in the past 4 months. The first test i did, 4 months ago, i got these numbers:

Cylinder #1: 185
Cylinder #2: 181
Cylinder #3: 177
Cylinder #4: 189
The number seem to have went up from the last test.

About 8 months ago i overreved my motor twice. Once hitting 8,500rpm and the second at 9,000rpm (yes back in the stupid days of acting bad, i've learned from my mistakes now).

The motor idles normal at about 725-750rpm. What worries me are the variances between all 4 cylinders, no two have the same numbers. My motor has about 6,700 miles on it right now with over a year of driving.

What do you guys think about the numbers? Can you guys foresee any future problems? Thanks

PS: Talk about bad luck, the motor did overheat once. The body shop that did the work for me forgot to tighten the hose clamp on the lower radiator hose and i lost all of the radiator fluid on the freeway in traffic about 5 months ago, thus causing the overheating.

 

Thoes are pretty good numbers, on par according to the Helms manual, and maximum variance of 25 between each cylinder, It looks good. but i'm surprised that misshifting/over-reving and overheating didnt cause any major damage accordng to the Compression test. IMO should be good

 

have you personally done a compression test on your car yet? if so, what were your numbers?

according to helms, the max allowable variation is 28psi...but my 15psi variation between cylinder number 3 and 4 kind of scares me a bit...with only about 6,700 miles on the motor i'm still burning some oil which leads me to believe that most likely the piston rings aren't fully seated yet...that should also affect the compression numbers right?

thanks for your reply jinn

 

well i know you have a different motor than me, but i have a B16 with god knows how many miles on it, and a lot of redlining (but no mis-shifts) and my compression test was 200 on all 4 cyls. for a new motor, i'd have to say you messed it up pretty well. theres no telling how long it will last. its too bad you had to learn from your mistakes on such a new motor

 

actually, most of the B series motor's have higher compression test numbers then the K20A2...i remeber reading a post somewhere on clubrsx that a guy took his car in for a compression test and the dealer told him he had good compression with 180psi's across all 4 cylinders...

the only thing that worries me right now is the variance between cylinder #3 and #4, it's about 15psi's...still in the acceptable range, but who knows what might be wrong...thanks for your post

 

Are you near sea level?

My ITR engine did about 190 across at sea level: 14.7 psi

 

you know what, i have no idea. I think i am. haha...i'm in San Jose, Ca. ---->me for not knowing if i'm at sea level or not...late

 

There are alot of determining factors, like what compression tester you use...

The RSX type S motor has 11:1 compression
compare your results by doing compression tests on your friends cars...
With the same compression tester, you should put out more PSI then a B16/ITR/GSR/h22 etc


With the compression tester I use, my friends USDM LS motor pulled 180 across all 4, my friends 10:4 JDM b16 pulled 220 across all 4, my CRVTEC with stock block puts down 220 across all four, my friends JDM h22 puts down 275psi across all 4, the compression is supposed to be 10.6:1. My old 89 crx HF motor put out 230 before i took it out.

all compression results are plus minus 10psi max

 

from Hondata: "Type-S and Type-R have the same exhaust valve springs. However the intake side uses F20C (S2000) intake springs for the outer spring and a Type-R for the inner spring. TODA also mentioned that Honda is now using single springs of a higher class material for the newer Type-R's"

9000rpms shouldn't be a problem. Keep in mind all compression testers are not equal. Rather than looking for high numbers you want constant numbers.
When I had a 94 Integ GSR, I had about 225 in all 4 cylinders with the tester I used (with 100,000 miles).

 

I have heard of people bending valves at just 9,100 rpm on the Type S...what are the signs of a stretched (edit)valve(edit)? would that effect compression numbers?

that's exactly what worries me, the variance between all 4 of my cylinders...no two are alike. Thanks for your post also.


[Modified by sjracer, 7:23 PM 4/8/2003]

 

it's pretty rare for there to be more than two with the same compression #'s.

#3 is usually low on i-4 motors anyhow. 1-2-4 have much lower variances between each other.

Personally, since the results are pretty consistent from your first measurement to the second, I wouldn't worry too much.

Was the first measurement pre or post over-rev?

 

If you have bent valves from a misshift, you will know. Your idle would definately not be normal because you wouldn't get any compression on the cylinder/s with the bent valves and if this was the case, you'd get a CEL for a misfire.

 

both compression measurements were taken a couple months after the over-rev...thanks for your reply...it's good to know that most Inline 4 motors have a weaker number 3 cylinder...late

 

i understand that, but what if you have a slightly stretched valve? what would be the results of that? would that effect compression at all? thanks for your reply also.

 

i've never heard of a stretched valve.

do you mean stretched rod?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chunky &raquo;</TD></TR><TR><TD CLASS="quote">i've never heard of a stretched valve.

do you mean stretched rod?</TD></TR></TABLE>

no, i actually mean "stretched valve." a couple of people over at clubrsx had two or more "stretched valves" due to an over-rev. thanks for your reply also.

so i ask again: would a stretched valve affect compression test numbers at all?

 

Stretched valves aren't real common, that's probably why you've never heard of it.

It's actually called "necking" I believe..

Anyways, I did a compression test today on my 00 JDM ITR engine again, I thought I'd throw up the numbers in this thread in case someone would like to compare or check them out..

215, 210, 208, 208

 

heres my numbers 310 310 305 310, could have went higher but i have a pin that stops it after 310. oh I have a

b16 head ported and polished with JUN IIIs
b18c1 clock with CTR pistons (12:1 compression)

 

Just another update.. those numbers I just posted are not right. I retested a fw minutes ago and got over 255 psi on my gauge. Unfortunately that's as high as it goes, so thats the end of the story for now untill I find a higher gauge..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Freakzilla &raquo;</TD></TR><TR><TD CLASS="quote">heres my numbers 310 310 305 310, could have went higher but i have a pin that stops it after 310. oh I have a

b16 head ported and polished with JUN IIIs
b18c1 clock with CTR pistons (12:1 compression)</TD></TR></TABLE>

okay, i think we are getting a little (edit)off(edit) topic here...please post numbers for the RSX Type S ONLY! all other compression readings from other cars with a motor other then the K20A2 will do me NO good, since i can't compare them to my readings! Thanks

 

Try clubrsx.com

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Nameless EJ6 &raquo;</TD></TR><TR><TD CLASS="quote">Try clubrsx.com</TD></TR></TABLE>

haha i did, the same time i posted this thread over here...so far i got only one reply over there...more people answered my post over here then on clubrsx. can you believe that?

i don't think a lot of people do their compression test over there...that one person who posted his compression number's basically got 195psi across 3 cylinders and 185psi on the 4th.

 

I have an 02 type s with 140k on the car. Cyl 1 is 247 , Cyl 2 is 140. Cyl 3 is 235. Cyl 4 is 147. Engine warmed up.

 

Also all plugs pulled, injectors unhooked, held throttle wide open, cranked for 5-7 seconds.

 

This thread died in 2003. May it rest in peace.