Fixing poor leakdown, Cyl 1 leaks at 50%, rest are cool. |
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Fixing poor leakdown, Cyl 1 leaks at 50%, rest are cool. |
VaccaRabite |
Oct 24 2007, 07:00 AM
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#1
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En Garde! Group: Admin Posts: 13,554 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region |
So, at the Sterling meet I did a leakdown test on my motor, and found a problem with Cylinder 1. 45% leakdown, but 120 lbs of compression. Was tempted just to let sleeping dogs lie, but pulled the head off.
What was going on was clear as soon as we did that, the head was not totaly sealed to the cylinder, off by a very small amount. Instead of having the head recut, I decided to try and lap the two of them together. So, last night I hand lapped them, using ground graphite to check for even contact. I got good contact after the third round of hand lapping (lap, clean, check). Now I need to get the jug back on the block. I have a ring compressor on the piston, but I can't ficgure out how to get the head back on. Do I have to take the piston head off the rod? If so, how do I get it off. It looks like that tis a spring keeper that needs to be removed. Is there anyhting on the rod the needs to be loosened before I can pull the pin out to remove the piston head? Obviously, if there is a trick to getting the jug back on without pulling off the piston head, I'd like to do that. Zach |
Jake Raby |
Oct 31 2007, 11:10 AM
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#2
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Engine Surgeon Group: Members Posts: 9,398 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
Typically any leak at the sealing surfaces will effect the future ability of those surfaces to seat in the future, sometimes lapping doesn't cure the issue..
This sounds like it may be one of the cases like we are seeing frequently these days that have a collapsed register, needing mill deck work to remedy the problem.. The GA cases are the absolute worst. |
VaccaRabite |
Oct 31 2007, 11:57 AM
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#3
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En Garde! Group: Admin Posts: 13,554 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region |
Typically any leak at the sealing surfaces will effect the future ability of those surfaces to seat in the future, sometimes lapping doesn't cure the issue.. This sounds like it may be one of the cases like we are seeing frequently these days that have a collapsed register, needing mill deck work to remedy the problem.. The GA cases are the absolute worst. Collapsed register? Sorry, I don't know what this is yet. (learning every day) Zach |
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