Just did a compression test on my 1998 gsr motor and it was 180 170 180 190 from 4-1. Is that pretty decent?

 

Could be a lot worse. Numbers are close, but low. Might want to start saving for a rebuild or something.

94-01 b18c1
nominal: 270 psi
minimum: 135 psi
max var: 28 psi

What kind of mods you have, how many miles on engine?

 

hey, after i bought my car, i found out that it has been sprayed. I would love to do a compression test. Did you do it yourself? if so was it easy? If not how much did it cost? thanks, sry to interupt post.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tegG2 &raquo;</TD></TR><TR><TD CLASS="quote">\

94-01 b18c1
nominal: 270 psi
minimum: 135 psi
max var: 28 psi

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

where did you get these numbers at?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by djtony5 &raquo;</TD></TR><TR><TD CLASS="quote">Just did a compression test on my 1998 gsr motor and it was 180 170 180 190 from 4-1. Is that pretty decent? </TD></TR></TABLE>

They are not bad, but they could be better. You can perform a valve adjustment and retry the test.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by forumnoobie &raquo;</TD></TR><TR><TD CLASS="quote">hey, after i bought my car, i found out that it has been sprayed. I would love to do a compression test. Did you do it yourself? if so was it easy? If not how much did it cost? thanks, sry to interupt post.</TD></TR></TABLE>

It is easy and cheap.

http://www.c-speedracing.com/h...t.php

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

where did you get these numbers at?</TD></TR></TABLE>

They are in the Helm manual.

 

The engine is about 106,000. Well I have done a compression before with a snap on and got 200 70 165 210. So I took apart the head and drop the oil pan while I'm at it and took the head to the machine shop for them to change the exhaust bent valves that I had and I change the piston ring on cyl 3 and 2. This is done after a month of driving with a cheap Actron compression for about 40 dollar at Autozone. Maybe If I retest with a snap on tester the compression might bounce up a bit? Iono. But um yes it was fairly easy to do. Just buy the compression tester kit, get your engine up to operating temperature, disconnect the spark plug wires and get all the spark plug out. Take out the number 15 fuel fuse. Plug the tester into the cyl and have someone push the gas pedal and clutch all the way down and crank the car until the number doesn't rise anymore.

 

The ultimate pressure of the compression test is gauge related. The variability is not.

 

I have a B18a1 motor that has almost 200k miles on it. it has 150 on 3 cylinders and 145 on one when i did my compression test. is it possible that my engine has been rebuilt? or maybe the previous owner just really took good care of it? i dunno....

 

Its good compression! anything lower than 100 is not good!!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by forumnoobie &raquo;</TD></TR><TR><TD CLASS="quote">hey, after i bought my car, i found out that it has been sprayed. I would love to do a compression test. Did you do it yourself? if so was it easy? If not how much did it cost? thanks, sry to interupt post.</TD></TR></TABLE>

How to...
http://www.c-speedracing.com/h...t.php

I just recently did a compression test on my GSR as well, 218, 230, 230, 240, give or take a couple of psi.

its a 97 with 108k miles.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RagingAlcoholic &raquo;</TD></TR><TR><TD CLASS="quote">I have a B18a1 motor that has almost 200k miles on it. it has 150 on 3 cylinders and 145 on one when i did my compression test. is it possible that my engine has been rebuilt? or maybe the previous owner just really took good care of it? i dunno....</TD></TR></TABLE>

thast not horrible but not that good. i have 200psi across with a 93 b18a 156,000mi.

 

i guess thats koo if you're running all-motor. i dont plan on doin the ls/vtec thing tho...i'll just straight turbo that thing. how do u figure out ur compression ratio anyway?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RagingAlcoholic &raquo;</TD></TR><TR><TD CLASS="quote">i guess thats koo if you're running all-motor. i dont plan on doin the ls/vtec thing tho...i'll just straight turbo that thing. how do u figure out ur compression ratio anyway?</TD></TR></TABLE>

Total volume in cylinder at BDC / Total volume in cylinder at TDC.

You can not figure out compression ratio with a compression test.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RagingAlcoholic &raquo;</TD></TR><TR><TD CLASS="quote">how do u figure out ur compression ratio anyway?</TD></TR></TABLE>

try this...
http://www.c-speedracing.com/h...c.php

 

Has anyone taken their car to the shop to get a compression test? if so, how much did it run them?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by forumnoobie &raquo;</TD></TR><TR><TD CLASS="quote">Has anyone taken their car to the shop to get a compression test? if so, how much did it run them?</TD></TR></TABLE>

No idea on how much it'll cost to get it done, but its pretty easy to do it yourself. The compression on my 200k+ motor is 160 150 160 160. I think that's alright considering how old my motor is.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by djtony5 &raquo;</TD></TR><TR><TD CLASS="quote">... Just buy the compression tester kit, get your engine up to operating temperature, disconnect the spark plug wires and get all the spark plug out. Take out the number 15 fuel fuse. Plug the tester into the cyl and have someone push the gas pedal and clutch all the way down and crank the car until the number doesn't rise anymore.</TD></TR></TABLE>

I thought you should let the head cool down before removing the plugs, don't you risk tearing the soft aluminum threads out?