Okay, I did a compression test today and here are the numbers:

#1 - 235
#2 - 240
#3 - 240
#4 - 190

I checked the Prelude service manual and it listed that compression numbers should be approximately:

250rpm @wideopen Throttle
Nominal - 185 psi
Minimum - 135 psi
Maximum variation - 28 psi

So by the looks of the numbers, #4 is the only one that's getting proper compression and I read somewhere that if your compression numbers are really high, you have carbon build-up in the combustion chambers. I was wondering what numbers some of you guys are having cuz my numbers look a bit off.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by StickyDilJoe &raquo;</TD></TR><TR><TD CLASS="quote">Okay, I did a compression test today and here are the numbers:

#1 - 235
#2 - 240
#3 - 240
#4 - 190

I checked the Prelude service manual and it listed that compression numbers should be approximately:

250rpm @wideopen Throttle
Nominal - 185 psi
Minimum - 135 psi
Maximum variation - 28 psi

So by the looks of the numbers, #4 is the only one that's getting proper compression and I read somewhere that if your compression numbers are really high, you have carbon build-up in the combustion chambers. I was wondering what numbers some of you guys are having cuz my numbers look a bit off.</TD></TR></TABLE>

ahh something is wrong with that... thats not right..

my buddy with a built h23 with a 12:5:1 compression is running
260 in each cylinder. He cant even run pump gas anymore.

He is fully built! ha ha

did you buy a car with a built motor and a blown cylinder?

Or is your guage fucked?

You cant be running that type of compression on the motor. no way.

 

Nope, the motor came stock from HMO and looked new when we opened it up before the swap. Then I ran into a few injector problems and now it runs rough and smokes so I did a compression test and these numbers came up. Other than the intake and the headers, the motor is bone stock. I know the numbers are bit off, just trying to figure out why...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by StickyDilJoe &raquo;</TD></TR><TR><TD CLASS="quote">Nope, the motor came stock from HMO and looked new when we opened it up before the swap. Then I ran into a few injector problems and now it runs rough and smokes so I did a compression test and these numbers came up. Other than the intake and the headers, the motor is bone stock. I know the numbers are bit off, just trying to figure out why...</TD></TR></TABLE>

A bit off? Thats crazy if you are pulling those numbers off!
Honda motors online? no such thing as a new motor. You might have ran into something other then stock with a blown cylinder, or your guage is fucked!? i dunno mang. weird to me.

 

Well I didn't exactly say it was new but the motor was clean. After the swap, everything was fine and I drove it around for a day then like the moment I rolled up to my driveway, it started running like ****. Strange thing is that everything seems normal, temperature is perfect, no check engine lights, nothing.....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by StickyDilJoe &raquo;</TD></TR><TR><TD CLASS="quote">Well I didn't exactly say it was new but the motor was clean. After the swap, everything was fine and I drove it around for a day then like the moment I rolled up to my driveway, it started running like ****. Strange thing is that everything seems normal, temperature is perfect, no check engine lights, nothing.....</TD></TR></TABLE>

have you ran your car in the 1/4 mile or anything and had freak numbers or had any street races and beat the **** out of cars you wouldnt even think of owning?
This sounds sketchy?

 

Nope, the car has barely even been out of my driveway.....Car still runs strong despite the numbers and like I said before everything is cool. Just don't now what's up with it....if it weren't for the smoke, I'd be driving it by now.....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by StickyDilJoe &raquo;</TD></TR><TR><TD CLASS="quote">Nope, the car has barely even been out of my driveway.....Car still runs strong despite the numbers and like I said before everything is cool. Just don't now what's up with it....if it weren't for the smoke, I'd be driving it by now.....</TD></TR></TABLE>

Have you tested you cylinders more then once?
If so get a new compression tester and if you still get the same readings take it to a shop and get that **** tested.

 

I just bought the compression tester today...it's brand new...

 

the higher compression is fine for a jdm h22. mine runs 250 in each cylinder.
but that one cylinder at 190 is not good. try the old oil through the sparkplug hole trick and see what happens then, to find out if it's rings or valves. i've got money on rings.

 

Yeah that's what I was afraid of. Didn't really want to mess with the block...I'll try it and see what's up. Just thought that the numbers would have been correct if it had been in the 190's....

 

those numbers are fine, except for the #4. its normal for jdm h22s to have 240-250 psi stock. next time you do a check, put a small amount of oil down in the #4 cylinder (no more than a cap full) and if the compression raises then the culprit is your rings.

mine read 240 across except for the #4 which is also at 190. i suspect it to be the rings because i just did a complete valve job 4k miles ago. also, you wont be loosing too much power from it, i have only lost about .2 in the 1/4 mile with the lower comp. in #4.

those numbers you quoted from the manual are for the usdm motor it seems...

 

also, lots of times guys make the mistake of doing compression checks on warm engines. compression tests are to be made on a cold engine, WOT, and w/ the ECU fuse pulled so it doesnt try to dump fuel into the cylinders and cause a false reading.

remember, cold motor, WOT, pulled ECU fuse. this will give more consisitant #'s

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kentucky accord &raquo;</TD></TR><TR><TD CLASS="quote">
remember, cold motor, WOT, pulled ECU fuse. this will give more consisitant #'s</TD></TR></TABLE>

Can you explain to me why? everywhere i've read, every good mechanic i've talk to, every compression gauge i've bought said warm engine.
I'm not saying you're not right, i just wanna know why you say that.

 

Those numbers are bad for the H22 I did my compression check about 2 weeks ago and my numbers were 226-195-215-225 and I know i have a problem in one cylinder

Accordhybrid

 

first thing first, how many time you crank each cylinder? and you did the same number of time with all four cylinders ,right?

 

i did a compression test on my motor (h22a) and got nearly identical numbers to yours after hydrolocking it...i was at 245-235 in 2,3,and 4...but number 1 was at about 185 psi...2 weeks later, boom, rod through the side of the block...ended up that the intake valves were bent and the rod was slightly bent as well...anyways, listen for any kind of knocking sounds coming from the motor when you let off the gas...don't do what i did and learn the hard way!

 

On my JDM h22a/LSD lude i got 210-210-205-190 . After warming the car up for about 20 minutes i recompressioned it and the # 4 cylinder came out fine as well I guess the cylinders needed to get oil and seal correctly, which kind of makes sense. Those jdm motors sit there for so long.

 

the gauge at hmo could read a little high, when i went and picked my h22a up and they did the test is was about 250 in all 4 with at the most 6 cranks, or like many said h22a's just run high...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kentucky accord &raquo;</TD></TR><TR><TD CLASS="quote">also, lots of times guys make the mistake of doing compression checks on warm engines</TD></TR></TABLE>

I'm not sure where you got that info. from. But that statement is incorrect.
When the engine is cold the ring are not sealing - metal contracts when cold and clearance are at is greatest. When engine is warmed up metal expands and clearance are at is closest and this when rings are sealing more.
When doing a compression test you are testing the rings if they are sealing. So why would you check compression when engine is cold?

But if your seriously believe that, I guess myself and all other Master Technicians in the automotive industry have been doing it wrong.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kentucky accord &raquo;</TD></TR><TR><TD CLASS="quote">also, lots of times guys make the mistake of doing compression checks on warm engines. compression tests are to be made on a cold engine, WOT, and w/ the ECU fuse pulled so it doesnt try to dump fuel into the cylinders and cause a false reading.

remember, cold motor, WOT, pulled ECU fuse. this will give more consisitant #'s</TD></TR></TABLE>

Compression checks are supposed to be done on a warm motor because manufactuers size the piston and rings very slightly smaller due to the fact that when metal gets hot it expands. when the motor reaches operating temp the pistons expand to take up the gap and copletly seal the combustion chamber.
Only the do you get the true amount of compresion each cylinder can make.
If the piston was sized to give perfect compression right at start up the piston would then expand and seize in the cylinder.

 

Opps sorry didn't read to the bottom of the thread

My h22a made 210 on five cranks warmed up in every cylinder.