Below is my post on the 390 from last year, just after MAPA. I confirmed all the"facts" with Lycoming at Sun & Fun last month. For most of us, with the new prop, the governor work, recalibrating some of the gauges, reworked baffling, hoses and mounts and who knows what else, the conversion will cost north of $50,000 out the door, for several knots and a higher fuel burn.
The several 177's and one M20J with the conversion were Lycoming test cases, had other mods done at the same time, and results are anything but scientific.
Unless Lycoming reduces the cost dramatically, it's a loser, IMHO. Hope, of course springs eternal.
Posted Sep 22, 2009 12:25 PM
Lycoming was at MAPA and gave us an update on the IO-390 A3A6 STC for the J model. It should be ready next month and the E and F, I believe, will following shortly thereafter.
The conversion however, will require a Hartzell 2-blade or 3-blade propeller, work on the governor, new hoses, new motor mounts, and maybe some other re-configuration work. Cost of the engine alone will be around $36K, and given a new prop, the other work, and installation, it sounds like a $50K+ job. Ouch!!
For that you"ll get roller tappets, angled valves, Slick mags, tuned induction, 10 more HP, another 4 knots, about a .5 GPH increase, and a 2 year warranty on labor, parts, and accessories. Your exchange core must be in operable condition.
Email your questions and comments to wgierke@lycoming.textron.com
As reported by the Cezzzzna Pilot's Association (CAP), Lycoming's Mike Kraft was quoted as saying "You *can* run your Lycoming engine lean of peak. And Lycoming wants to help teach you how!" Lycoming plans both an updated Service Instruction 1094 on leaning, as well as an interactive online training course in the near future. Until then, their "don't do it unless you know what you're doing!" admonition stands. But their progress on this issue is heartening. Incidentally, the new iE2 series of electronically controlled Lycoming engines will run lean of peak.
Will wonders never cease?