ok so im curious on what my compression should read on a compression check...like what are the numbers it should be in between???

 

the numbers will vary from gauge to gauge, you just want to make sure the numbers are consistent across all 4, if the numbers are low, then do a leakdown test

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tartje &raquo;</TD></TR><TR><TD CLASS="quote">the numbers will vary from gauge to gauge, you just want to make sure the numbers are consistent across all 4, if the numbers are low, then do a leakdown test</TD></TR></TABLE>

 

alright thanks a lot...im good then i think lol

 

talking about Comp test I just did one today to see if my motor is running healthy ..first cylinder 190psi, 2#180psi, 3#200psi, 4#200psi.

So what You guys think about the numbers is it good or bad ??

Sorry for hacking in your thread.

 

its cool man i think those are good numbers...but like the other guy said it verys on guages

 

Cylinder #2 seems to be on the borderline problem side.

 

i juts did one tonight from right to left 175-125-200-260-


then again we blew my **** on the dyno also

thats a motor that have 280 across

im waiting for my buddy to post some videos , nitrous is fun

 

damn, 260 on #1. I have the same question, what is the compression supposed to be at?? I know they shold be equal, but a good motor should have a set number? I know its supposed to be more than 200psi.

 

I ran solid low 230's on mine with a jrsc on it. I was very impressed and surprised to see those numbers with almost 100k on it and over 30k boosted miles.

 

damn, thats nice. Question for you then, i have a buddy whos selling his ITR motor to me, he keeps it real clean, hes giving it to me cheap just to hook me up, when he got it, it was 210 across, as of right now, i think its 200 across. What do you think? Should i still get it?

 

which type r motor is it tho cus that will change the numbers some....jdm is 11.0:1 and usdm is 10.6:1 so what would the difference be in those 2???

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nevrkno &raquo;</TD></TR><TR><TD CLASS="quote">which type r motor is it tho cus that will change the numbers some....jdm is 11.0:1 and usdm is 10.6:1 so what would the difference be in those 2???</TD></TR></TABLE>

It doesn't matter what the numbers 'should' be. It matters what they are.

Your variance per cylinder should only be 3-5%. Any thing more than that and you have a problem in the making.

If you get a low cylinder, pour a t-spoon of oil into the cylinder, and recheck. If the compression goes up, then the rings are going bad/not seated well. If the compression is still off, then you have a problem with either the head gasket or the head.

 

its a JDM type r motor

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by r6toeg6 &raquo;</TD></TR><TR><TD CLASS="quote">damn, 260 on #1. I have the same question, what is the compression supposed to be at?? I know they shold be equal, but a good motor should have a set number? I know its supposed to be more than 200psi.</TD></TR></TABLE>

when my motor was stock with 20k on the odo. it had 230 acrosss the board . thats what a USDM ITR runs stock .

 

I had 225-225-225-225 across the board on a dry test about 4 months ago.

 

I searched everywhere, but I cant find any solid info on what to expect as compression numbers after a stock, 1st oversize B18c5 rebuild.

My test before teardown yeilded 200-180-200-220. The car was about 7 mph down on top speed vs a fresh ITR on a long back straight, all things equal.
There was 100,000km on the last rebuild, but I was never satisfied from the start.

what should I expect?