Compression test: Should I rock these #'s or...
Thread Starter
Team Owner
Joined: Mar 2002
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Compression test: Should I rock these #'s or...
start shopping for a crate engine?
1: 135
3: 130
5: 115
7: 135
2: 130
4: 135
6: 135
8: 135
Obviously I'm only worried about #5. I squirted some oil into it, and it jumped up to 150.
So go or no on the original L82?
1: 135
3: 130
5: 115
7: 135
2: 130
4: 135
6: 135
8: 135
Obviously I'm only worried about #5. I squirted some oil into it, and it jumped up to 150.
So go or no on the original L82?
Thread Starter
Team Owner
Joined: Mar 2002
Posts: 24,160
Likes: 78
Oh forgot to mention all cylinders except #5 got to their # by the 2nd stroke. A couple of them might have eeked out a few more pounds on the third stroke but not much at all. 5 strokes on (dry) #5 didn't get more than 115, but with a squirt of oil it popped right up to 150 on the first stroke.
Race Director
Joined: Jan 2000
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From: Corsicana, Tx
2020 C2 of the Year - Modified Winner
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I'd say rebuild the original L-82. Unless you just want a whole new bigger motor.
JIM
JIM
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Joined: Apr 2000
Posts: 17,665
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Too bad about #5 most probably has ring problem or something similar, if they were all the same you are good to go. # 5 is too far out, especially when it comes up with oil in the hole. How does it run, if it runs OK and you can't afford to rebuild it, call it day and enjoy your Vette 
Actually a few calculations I made and you are close on the #5 so if it runs OK then forgeddabodit
Actually a few calculations I made and you are close on the #5 so if it runs OK then forgeddabodit
Melting Slicks
Joined: Dec 2006
Posts: 2,669
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From: Kingston Ontario
You could follow this up with a leakdown test to further identify where the leakage is. Could be a quick overhaul with a new set of rings and you're good to go.
Unless, lurkin' in the back of your mind for some time; "what do I need to see to warrant a new crate engine?"
Unless, lurkin' in the back of your mind for some time; "what do I need to see to warrant a new crate engine?"
Last edited by dannyman; Sep 26, 2010 at 09:53 AM. Reason: sp
Instructor
Joined: Aug 2010
Posts: 149
Likes: 0
From: Atlantic Beach FL
I think I would try a "shock treatment" of Seafoam, to see if the numbers improve. Carbon build-up can cause low compression numbers, so it is worth a try. I have saved many an outboard from "rebuilding" with a shock treatment of Seafoam. 1 can of Seafoam to 1 gallon of gas. Google "dunk method" "shock treatment" and you will see many success stories. It is worth a try.
Thread Starter
Team Owner
Joined: Mar 2002
Posts: 24,160
Likes: 78
Too bad about #5 most probably has ring problem or something similar, if they were all the same you are good to go. # 5 is too far out, especially when it comes up with oil in the hole. How does it run, if it runs OK and you can't afford to rebuild it, call it day and enjoy your Vette
Actually a few calculations I made and you are close on the #5 so if it runs OK then forgeddabodit
Actually a few calculations I made and you are close on the #5 so if it runs OK then forgeddabodit
