compression test results...opinions?

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Sep 23, 2011 | 02:07 PM

midwestjunk

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From: Addison, IL

compression test results...opinions?

i been sprayin my ls1 motor for a few years and decided to do a compression test to see how it has held up. the car is a LS1 with texas-speed stage 2.5 5.3 heads and a MS3 cam. stock 80,000 mile bottom end. the motor was cold. pulled all the plugs and checked each cylinder one by one. this is what i got.

#1 185
#2 180
#3 210
#4 180
#5 185
#6 185
#7 200
#8 190

is this normal? how does it compare to stock? why is one cyl 210 and one is as low as 180?

Sep 23, 2011 | 03:03 PM

ZeeOSix

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Quote:

Originally Posted by midwestjunk

this is what i got.

#1 185
#2 180
#3 210
#4 180
#5 185
#6 185
#7 200
#8 190

is this normal? how does it compare to stock? why is one cyl 210 and one is as low as 180?

There will always be a spread between the lowest and highest cylinder ... I would say 30 psi isn't that bad for what the motor has been through. If you had a really bad cylinder you'd see a lot more than a 30 psi difference across them all. IMO, nothing to really worry about.

Did you do them in the order you show above? If the battery was getting a little low near the end of the testing, it's possible the last few cylinders that were tested might show a few psi less.

Sep 23, 2011 | 09:48 PM

SOMbitch

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Looks really good especially on a cold motor.....

Sep 23, 2011 | 10:46 PM

salemetro

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From: Salem/Keizer

Quote:

Originally Posted by SOMbitch

Looks really good especially on a cold motor.....

Yeah...and 2 years of sprayin' it??? Not bad at all! Definitely nothing to worry about. You could always do a leakdown test, if you're uber-concerned.

Sep 23, 2011 | 11:22 PM

z99ls1

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From: kansas

Makes me want a shot of nitrous. Do you run a dry or wet shot? What kit?

Sep 24, 2011 | 01:54 AM

Black 99 Bird

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From: East, TN

Quote:

Originally Posted by z99ls1

Makes me want a shot of nitrous. Do you run a dry or wet shot? What kit?

Yeah, no kiddin!

Sep 24, 2011 | 08:35 AM

midwestjunk

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From: Addison, IL

dry 150 shot. nitrous outlet kit. 2 money races have been on 200 shot. its on a spray tune so it runs a bit fat crusing around but on spray its perfect. the car wouldnt add enough fuel by itself and it was very lean. had to permanently add more fuel through out the RPM range. 10.60 on a 150shot spinning. i was hoping for 10.0's on 200 when my suspension is sorted out. its just really difficult with the 6-speed.