- Sep 17, 2008
I did an Subaru installation in a Glastar for a third party. By the time it was done he could have bought the Lycoming and been flying a year earlier, and not had to have me spend a lot more time working out the bugs. It's neither cheap nor simple, especially if it's not a bolt-it-on conversion.In most aspects, my personal use of conversion engines rather than conventional aircraft engines has less to do with buy-in economy and much more influenced by running cost and technology. Most people, if they are honest, will admit that an auto conversion is not initially cheaper than a used Lycoming. The costs start mounting when you have to rebuild the mags often, perform top end rebuilds, etc. after relatively low hours in your homebuilt because well, you bought a used motor. At that point, the auto conversion that was a fresh rebuild really starts to earn its keep.
The redundant systems argument for certified "aircraft" engines remains something of a mystery to me. All auto conversions I am aware of- and that is not to say I am aware of them all, I am especially fuzzy on V6 and V8 auto conversions- have spark redundancy developed for them. Many use electronic fuel injection which is so much more reliable than a carburetor that even ignoring the efficiency and control provided by EFI it is laughable to attempt to argue a carb is in any way meaningful way safer or better. The fact is that GA would have converted a decade ago if the FAA had not, as per usual, made it so prohibitively expensive that to even consider it makes your bank account slit its wrists.
Used Lycs are fine if they've been looked after. I took them off the flight-school airplanes at TBO, with compressions still in the high 70s and no metal in the filters. There were another 1500 hours in them for a homebuilder. Magnetos need 500-hour inspections, with replacement of points and condenser usually at the second inspection. After 2K hours they should be overhauled or replaced and then they're good for another 2K.
EFI and EI will make it into GA if GA survives long enough, but someone is going to have to pay the shot and find some way to amortize it so it makes sense to buyers, or the FAA is going to have to get a lot friendlier and stop hindering progress with so many onerous fees and requirements for near-perfection. GA is 99.9% safe now, but they want 100%. They can't have that no matter how many rules they make. As long as humans are involved, accidents will happen, either through pilot error or though cheapskate maintenance as per owner demands. Even here on HBA we occasionally get people that want a stall/spin/accident-proof airplane that flies itself so they'll never get hurt. They can't have that, either. Risk aversion is far bigger now than it was when I was young, and maybe that's part of the decline in GA. And the media's hyping of every little aircraft incident or accident, while ignoring the carnage on the highways, isn't helping.