Hi Dave,

 I miss spoke about the flight levels and I apologize. What I meant was up to  FL290. We will not be RVSM Qual.

I have about 175 hours behind a Walter 601E also. We have a cabin pressure that goes above 10K when we reach FL22-FL23. I have been told we have a cabin leak which may be true but we also are using plenum air to cool the generator with a 2.5 in duct which I was told was unnecessary. The bottom  line is we need a stronger compressor in the walter to make power at FL270 and above.

 I would prefer a turbine that was more fuel efficient, had a high altitude compressor, 3+ times the TBO, more plentiful in the US, and no metric hardware.

 I am not saying there is anything wrong with the Walter powered 4P, I am just looking for better like everyone here. Isn't that why we fly experimental acft instead of spam can factory built?

Swaid Rahn