How do I interpret these Compression numbers?
#1
How do I interpret these Compression numbers?
Hi everyone! First post, currently shopping for 911 SCs.
Had one on the lift today for a PPI and was wondering if someone can help me interpret these compression test numbers:
155 - 155 - 185 - 185 - 180 - 160
This is a ROW 83 SC. Both seller and I are curious about them all being high but having significant differences. 155 all around for a never rebuild engine (~100k miles) with higher compression ratio would seem fair, but strange that three are even higher in the 180 range.
Double checked the results too.
Any interpretation as far as possible would be appreciated! Hoping to join the club soon!
Had one on the lift today for a PPI and was wondering if someone can help me interpret these compression test numbers:
155 - 155 - 185 - 185 - 180 - 160
This is a ROW 83 SC. Both seller and I are curious about them all being high but having significant differences. 155 all around for a never rebuild engine (~100k miles) with higher compression ratio would seem fair, but strange that three are even higher in the 180 range.
Double checked the results too.
Any interpretation as far as possible would be appreciated! Hoping to join the club soon!
#2
Rennlist Member
Get a leak down and find where the leakage is
#3
Thanks! We are doing that on Tuesday, was just curious if the fact that all of them are relatively high, just not close to each other, indicates anything. I will have to be more patient...
#4
Rennlist Member
Hard to say really. Leak down will tell the story. Do you know when the last valve adjust was done?
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#10
Rennlist Member
Adjust valves, while doing so put a wrench on the head studs and see if any of them turn. Then leak down. Listen for where the leakage is coming from.
Those numbers are bit uneven, want to see where it's coming from. And how bad.
Those numbers are bit uneven, want to see where it's coming from. And how bad.