| Go back to previous topic | | Forum name | Performance/Engine | | Topic subject | Major problem, need help fast. | | Topic URL | https://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=82122 |
82122, Major problem, need help fast. Posted by powellds, Oct-22-04 05:12 PM
Hey, I just rebuilt my car and I have a compression problem. I did a check and here's the results. Cylinders #1~ 120 #2~60 #3~120 #4~90. I know I probably bent an exaust valve in #4, but what the hell is up with #3? I have crower 2's and springs and retainers. SBI rockers and lashers, and ported and polished head. The head is completely built and I have a stock bottom end. Anyone please help.
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82123, RE: Major problem, need help fast. Posted by djtrickee, Oct-22-04 05:29 PM
so many questions...
new headgasket? get the head decked? torqued right? when did you do the test? what was the compressions before the test? what was the condition of the head and block before you put the head back on? cold or warm test?
sooooo many questions.
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82127, RE: Major problem, need help fast. Posted by powellds, Oct-22-04 10:19 PM
Ok, let me answer these in order. I put a new Fel Pro head gasket on it. I had the head resurfaced flat. I torqued the ARP Headstuds to ARP's specs and the normal tightening sequence. I did the test a couple of hours ago. I don't know what the comression was before the test, but it ran a 15.9 in the quarter before I did all of this. When the head was put back on the block, the head was in perfect condition, no leaks or anything. The block was also in excellent condition. So, what do you think?
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82128, RE: Major problem, need help fast. Posted by powellds, Oct-22-04 10:20 PM
Also, isn't it supposed to be around 120 on all of the cylinders?
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82129, RE: Major problem, need help fast. Posted by DarkOne, Oct-22-04 10:57 PM
If its a new valve job, they may not have had time to fully seal in the seats, depending on what kind of valve job it was.
Big cams will affect compression numbers. With more overlap, expect lower numbers.
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82131, RE: Major problem, need help fast. Posted by powellds, Oct-23-04 12:16 AM
I just had a 3 angle valve job. So I need to wait until they seat? So, that makes sense that Cylinder numbers 1 and 3 are 120 psi and cylinder numbers 2 and 4 are 60psi and 90 psi? Let me know, because I have a lot of work ahead of me if I'm going to take everything apart.
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82132, RE: Major problem, need help fast. Posted by powellds, Oct-23-04 12:17 AM
Oh yeah, if there was overlap, wouldn't it effect all the cylinders and not just the two of them?
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82134, RE: Major problem, need help fast. Posted by powellds, Oct-23-04 01:35 AM
Ahh haaa! The freakin pressure gauge is broken! I'm going to test it again tomorrow to see what's up. I'll let ya'll know what the numbers are as soon as I get them.
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