503 warm up

[Larry Mednick]

Tough question… IF the cooling system is sufficient not to overheat the engine on the ground I would warm it up “extra long” because you don’t want a cold seizure. On the other hand IF it can over heat on the ground I’m not sure what to tell you. Outside temperature will play a big roll in in warm up time. I would be more concerned with over heating on climb out or a lean mixture and would pretty much never fly anything without temp gauges. A 4 stroke you don’t need EGT, a 2 stroke you really do. I know PPG guys don’t have gauges. Then again those guys seem to have an awful lot of engine failures.

[Ed Haas]

Is your 503 fan cooled or free air? I always warm my fan cooled 503 for around 5 minutes at approx 2500 rpm before flight. That brings the CHT to around 200-250 degrees F. With 830 hours and counting, that seems to be working for me. Can’t speak to a free-air engine. Temp gauges are good insurance though and the money is worth the peace of mind.