Hey all,

I did a compression test the other day and numbers came back like this:

#1 190 #2 190 #3 195 #4 185. This was with the car at operating temperature and WOT

Now from what I've been searching, is that stock ITR motors pull 240+ across the cylinders? So is mine on the way out or what? I've heard if that the numbers are within 10% of each other, the motor is healthy. Please let me know what you guys think.

 

i, personally, would call that DONE...

i like to see no more than a 5-10psi difference. which is like 2-5%.

btw mine did 230s yesterday... try a different gauge/tester...




is there a compression test post every week? or is it just me?

 

I wanna know as well. Did a compression test and mines at 180 at all four cylinder. Does seem kinda low. I suppose that's why there's a bad odor smell every time I gun it.

 

Mine put down around 170 across all four cylinders, and still put down 163whp on a stock motor with an aem intake. Test was performed at Acura dealer, they said the motor was fine.
Your motor is probably fine.

 

isn't there 2 ways to doing a compression test and doesn't one or the other produce higher numbers? dry/wet?

 

hot/cold I think. Cold produces lower numbers, hot produces higher. I think having it WOT (throttle body open) makes a difference as well.

 

It`s fine !

 

My cold, dry test came out 270 270 270 270 on the engine I swapped into my EM1. On a 50 degree day. After the car sat all night. It was 40s at night. So it was a dead cold motor. It has ENDYN stamps on the back of the head, though...and the head is ported. So I'm guessing that maybe the head is milled or the head gasket isn't stock? IDK. Mine sounds like it has mild cams in it also.

I don't know anything about the engine. I bought a car from some kid with the swap already in it. Decided to swap it into my EM1. I kinda wish I just had a stock B18C motor instead lol. It rips pretty hard, though.

Sorry for the thread jack.

 

Every compression tester will give you different numbers. I have tested brand new Honda motors with a Snap-on, MAC, and Craftsman compression tester before.

Each tester will have higher or lower psi, that doesn't really matter, what your looking for is each cylinder to have less then a 15% difference in psi.

Also one of the most common mistakes is selecting a tester in which the head adapter does not screw into the cylinder head with the same amount of thread as the spark plug that came out. This lack of thread can be compared directly to adding extra volume in the cylinder head and will not represent the same pressure numbers as if the spark plug were reinstalled.

Your motor is good, and healthy, congrats man

 

That's what I wanted to hear. It was a snap-on compression tester. Thanks alot LankorDie. I'm positive I selected the correct adapter for the spark plug hole.

 

No problem man, glad to help

 

good numbers!!! mine were 195 across the board COLD!! 205 warm!!!

 

Thanks! I always wondered about that! Seems like this could easily to the disparity between various testers.

But when a motor gets tired does it always show up as a difference between cylinder pressures? IOW, can all 4 cylinders be "down" a certain amount, or is that extremely rare?

 

I did a test on my b18cr today (with my own compression tester). Noticed that the non-removable piece on the end of the hose had the same threads as the "adapter" thingie screwed on to it. Never noticed that before... meaning I could screw the compression tester into the plug holes without the adapter I purchased for it. But the hose wasn't threaded as far as the adapter, so it didn't go as deep.

So I did 2 tests. With the adapter, I hit 243 - 245 all the way across (warm, open throttle). Without the adapter, 215. It's easy to see how there can be a lot of disparity between tests.