Exhaust Valves and Exhaust Risers

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blsewardjr
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Re: Exhaust Valves and Exhaust Risers

Post by blsewardjr »

My DA40 Lycoming IO360 #1 cylinder had a static compression of 45/80 this past annual. Based on Mike Busch's advice above I was reluctant to pull the cylinder. Instead, my mechanic "lapped" the valve and was able to get the compression up to 63/80 cold. We're going to re-check after 25 hours.
Bernie Seward, IR, AGI
2003 DA40 N377DS
KCHO Charlottesville, VA
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RMarkSampson
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Re: Exhaust Valves and Exhaust Risers

Post by RMarkSampson »

Found this article from Mike Busch, published nearly a decade ago. Still very relevant. Apparently there is a part two to this article that discusses borescopes but I have not been able to google it. However, more recently, Mike Busch published an article in AOPA that discusses borescopes. Since you mentioned "rechecking at 25 hours" - when you pull that spark plug out for a compression check, sticking in a borescope is time well-spent.

https://www.aopa.org/news-and-media/all ... -borescope
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EAA_2010-07_dont-fail-me-now-(exh-valve).pdf
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