Usually, we look for something greater than 60/80 when doing compression checks on Lycoming engines. A reading such as this one (36/80) really warrants further investigation. In this case, a borescope picture showed an exhaust valve that was in danger of imminently failing. It’s easy to find the air leakage when doing a compression test by placing your ear at either the oil filler tube (usually indicates leakage by the rings) or at the exhaust stack (will indicate exhaust valve leakage) or at the air intake (which will indicate a leaking intake valve).
In Case You Missed it
RV Quick Stick
Bob Hadley - 0
I live in a pretty cool neighborhood, which happens to include a couple of...
Practical Electrical
Battery facts and fables—Lithium considerations. By Robert L. Nuckolls, III.
Wind Tunnel
Thrust-line adjustment is a powerful tool for tailoring flying qualities, but it’s complicated.
Metal Working 11-part Series
Now the exceedingly popular and extraordinarily useful 11-part Build YourSkills: Metal Series is available as a single PDF. This must-have additionto your library was written by RV-7 builder Dan Checkoway and carefullyillustrated for first-time metal-workers and old hands alike. Mosteverything you need to now, from material handling and cutting to deburring,drilling and riveting is in this series.