C-85-12 Exhaust Valve Guide

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rominoff
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C-85-12 Exhaust Valve Guide

Post by rominoff »

Had a beautiful flight in the pacific northwest yesterday, today was a different story. On startup, engine ran very rough. Shut it down, felt all the cylinders, one was cold. Took off the valve cover and found the exhaust value stuck open. Borescope, no issues. Rope trick in the cylinder, forced the valve closed. Removed the spring cap and found the problem... the valve guide is seized onto the valve stem and moving as one. I am in need of a serviceable cylinder, thought i would ask for recommendations. thanks in advance
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6643
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Name: John C
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Re: C-85-12 Exhaust Valve Guide

Post by 6643 »

If you know the history of the cylinder, and it's got a reasonable number of hours since new, you may be able to have an oversized guide installed. Otherwise, replace it with new or one of known history. My "rule" is if it's older than first run, or 2000 hours since new, and it was overhauled once, it's probably not worth repairing.

I'd also ream the guides on the other three as a preventive measure.
8342
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Re: C-85-12 Exhaust Valve Guide

Post by 8342 »

I have the old cylinders from my rebuild. C-85.
They are in pretty good shape with only a hundred hours on them since they were overhauled last.
Send me a PM if you are interested, I can send you pictures tomorrow.
$300 plus shipping.

Rick
rominoff
Posts: 39
Joined: Sun Dec 06, 2020 7:36 am
Location: Bothell, WA
Name: Bradley Bell
Aircraft Type: '47 C140; '48 NAVI
Occupation-Interests: Software & Systems Development; A&P/IA
Contact:

Re: C-85-12 Exhaust Valve Guide

Post by rominoff »

Rick,

Sending you a PM

Bradley
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