ya, I know... occupational hazard I guess. But when I see compression numbers that low it makes me wonder. Even my old international hit-miss will make numbers higher if you crank it long enough. I see so much variance in technique using the "run it with the starter" method that when I don't feel comfortable using it to judge the health of an engine that i havent known since it was new.
I manage the maintenance on a dozen planes - doing a Skylane with a Continental O-470 right now (6 cyl, opposed, 471 Cu. in. 230 hp). Diff test, borescope, oil analysis, examing the contents of the oil filter, inspecting all 12 spark plugs, fuel flow/cyl temp/exhaust gas temp data stored and downloaded... all that really spoils a mechanic and makes it pretty easy to diagnose engines
I'm still a rookie when it comes to Model As though... the temptation to put a bunch of probes on it is strong... It's hard to resist the dark side
