Originally Posted by
Big Pistons Forever
Manwell
In case of the Tomahawk failed valve did you find the engine ran quite rough right after start up but smoothed out as the engine warmed up ?
i ask because an engineer diagnosed a failing valve in a flight school airplane I was flying. In that case the cylinder was repaired before the valve failed but in his opinion he thought valve failure was imminent. After that I always look out for this symptom particularly in the small Lycomings which are.known for exhaust valve guide problems
Not from memory BPF. It happened at about 20' and it had been operating smoothly at full power up to that point which indicates a sudden failure. If it ran rough right after start that would indicate a sticking valve and I don't think that would end up causing valve failure, but it is possible I guess.