We’ve been fighting RPMs on our engine forever. On our second flight performance was good, but the static was about 2150 RPM, and best in flight was 2335 RPM. This is complicated by the fact that the HIGHEST EGT was 1083, which is just too low (they ought to be at least 1280 F, I’m told by Magnum Engine). Also, from talking with Craig Catto, we should be getting at least 500 RPM difference from static to in-flight, though to be fair, Dave was holding the speed down because we haven’t done high speed or flutter testing yet. Net, we’ve got an issue we’re working here, because Gene at Magnum is concerned that we’ll glaze the cylinders if we don’t get more RPM. Craig can depitch the prop, he tells me, by adding material to the back of the blades (which could be removed later, after the engine is broken in), but I’m looking for a shorter prop to play with for now. Also, since the EGT’s are so low, we’re going to send our fuel servo and injectors back to Airflow to have it recalibrated, as it seems we’re probably way off on mixture. Related to this, we’re trying to our Floscan 231 to work properly so we know how much fuel we’re really using.

Posted By: Brett Ferrell
Thursday April 10th, 2008 at 9:24 PM

Categories: Blog
Tags: Blog

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