kellysmith

iTrader: (4)

Motor stock ls1 with ls9 head gaskets and 317 heads ls9 cam
FM Turbo T70 7.25psi

compression results
1. 142
3. 140
5. 139
7. 140

2. 145
4. 180
6. 142
8. 140

Any ideas on whats going on with #4 cylinder??

Trying to get car all dialed in to take to speed inc for dyno tune so no issues come up.

thunderstruck507

iTrader: (18)

are you sure you cranked long enough on all of them? did you try any more than once?

kellysmith

iTrader: (4)

ya must not have been cranking long enough just retested. Thanks for the help but now i got a low one!

7. 175
5. 180
3. 180
1. 183

8. 179
6. 180
4. 190
2. 145

gonna grab a bite to eat and retest #2 when i get back in 10min or so

kellysmith

iTrader: (4)

all good now went and rented a tester with longer threads low cylinder is 163 high is 190 the other 6 are 175-182. Thanks again for your help.

thunderstruck507

iTrader: (18)

no problem, but I would expect them to be a little closer than that, all mine were 190-205

89 formula350

iTrader: (8)

sounds like alot of cranking.. is the fuel injectors and fuel pump disabled? (not just the coils) this can cause low readings