Ok last night compression tested my motor.......I was under the understanding that h22's run bout 185....across

I have a JDM Non-S motor ( I think 10:6:1) compression.

Well I know result are Great but it's striking me as a little high....
I got

260...260....257....260...

I checked the US helms and it stated 185 with variance of course...
I know the upp'd compression of a JDM motor will boost it a little....but 260...across does that seem TOO high??

sorry I know I could find this with search but unfort. I'm at work and comp. at home is Sh!tting on me.....

so please don't reply with a cut and pasted search thread....just want qwik answers....thanks guys

 

I've seen #'s that high on JDm motors before.

You might have a little carbon build-up but the numbers look good

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SKDRCR &raquo;</TD></TR><TR><TD CLASS="quote">I've seen #'s that high on JDm motors before.

You might have a little carbon build-up but the numbers look good </TD></TR></TABLE>

I was thinkin same thing bout carbon build up...poss upping...it I know numbs look good
I was just concerned cuz they seemed way high to me.
thanx

 

carbon can do that

 

you could try seafoam if you want then redo the comp test.


oh nick,
&gt;*

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Shakes &raquo;</TD></TR><TR><TD CLASS="quote">you could try seafoam </TD></TR></TABLE>

Good idea and you could also try some ATF

If you take off your throttlebody and check the carbon build up on that thing you should get a good idea of how much carbon build up you got

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Shakes &raquo;</TD></TR><TR><TD CLASS="quote">you could try seafoam if you want then redo the comp test.

</TD></TR></TABLE>

Why in the world would you want to use Seafoam unless you have to? That stuff dries the hell out of your seals. If you need proof, put your hands in some kerosene (basically what SeaFoam is made out of), leave it for 5 minutes, and clean off your hands. They'll be cracked, white, dead hunks of skin. That's what it does to your seals, BUT also does it to carbon so it ends up cracking off. IF you want that, go for it. If you want to do it the smart way throw a bottle of Regane / Techron / STP Fuel treatment into your fuel system to clean it off.

OR the cheapest way to do it (if you don't want to risk anything) is get a bug sprayer that's clean and spray water into the TB while the car is running. It'll steam clean the engine.

 

I wouldn't be too concerned about the #'s being "crazy high". My tests come back with 250-255 on a clean JDM block and a clean (no carbon build up head). Some fuel treatment, like TimeRacer said, can't hurt in case you do have some build up.

I just put in flat valves and milled the head (it warped on me) so I can't wait to see what the compression is now.

 

they are good...its important that they are consistent.