"Robert M. Gary" wrote in message
om...
I had to cancel a flight today because one of the plugs in my Mooney
doesn't seem to be firing (tried to burn it clean but no luck).
Anyway, it got me wondering what would happen if you lost both plugs
in a cylinder during cruise (certainly take off would suck). I often
cruise around in my Mooney at 45% power (as indicated on the EDM). I
would like that I would have at least 45%, right? I'm not planning on
flying with a dead plug but really just an academic curiousity.

As the other poster mentioned, it ain't very fun if you lose one on a
four-banger. I've lost one under tow before on a PA-12/O-320 combo, was
kind of iffy for a little bit, and defiantly were some vibrations. But was
able to burn the oil off and got home ok. We had a pilot blow a jug clean
off the crankcase, thing was dangling by the plug wires; she made it back ok
too. Of course, we had 150hp engines on airframes designed for 105hp, so we
had a little extra room to play with.

Also lost one in a 182 a couple of times. Worn valve guides this time, only
way I knew was a loss in airspeed and EGT was 0 on #4. Kind of spooked me;
it could have been like that on runup and I wouldn't have noticed. That
plane ended up eating 4 valves before the club finally got around to
replacing that engine.