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 |
VaccaRabite |
Dec 29 2007, 12:08 AM
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#2
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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 |
Okay, so I measured deck height today with Josh's help.
#1 was the same as #2. I don't have to get my case decked! Its a problem with how the heads were cut. The heads need to be recut, taking as little material off as possible. I took off the tin and all the other bits today, the heads will come off tomorrow after I do some baby shopping with the missus. Zach |
orange914 |
Dec 29 2007, 12:10 AM
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#3
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http://5starmediaworks.com/index.html Group: Members Posts: 3,371 Joined: 26-March 05 From: Ceres, California Member No.: 3,818 Region Association: Northern California |
Okay, so I measured deck height today with Josh's help. #1 was the same as #2. I don't have to get my case decked! Its a problem with how the heads were cut. The heads need to be recut, taking as little material off as possible. Zach how many cc's are they now? are you running carbs or f.i.? mike |
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