Alternator conversion for lycoming

[Dooley]

Has anyone put an alternator on their lycoming powered 170? The adjusting link broke on my generator, (someone had already shortened it). Everything else is worn out (elongated mounting holes) including the end plates on the generator. Its $225 for an exchange 35A gen and $350 for mounting brackets from El Reno. I know 70 Amps is way overkill but its lighter and I can't help but think 50 years must make some kind of difference in electrical engineering. There is a gen to alternator conversion kit available from Plane Power in Granbury Tx. I know its not STCd for 170s but I could be a trailblazer. Will I have to reinvent the wheel? My engine came of a Mooney, seems like there should be some basis for a field approval there since it is STCd for them.

[ghostflyer]

You can never have too much power, so however we have fitted a plane power alternator and a plane power voltage regulator [these are cheap] to a aircraft and we are very impressed with the preformance [rock steady voltage output]. We had the Kelly alternator problems not once but 3 times all changed under warranty. I was about to use the Kellys as sinkers when we go deep sea fishing . We are now in the same position as you with another 170 but with a superior 180 hp engine fitted and its plane power again. However please contact Plane Power as I was under the impression there is a STC for the mighty 170

[Dooley]

Well its nice to know someone has done it. I really like the mount, the whole thing is a lot sturdier than the original. Of course I have to take off the prop cuz the belt is to short and I need new ammeter. Hopefully I will be able to make the paperwork match up with this improvement. Isn't it a shame it is so difficult to bring our airplanes out of the 1950s.

[Jr.CubBuilder]

I used the Plane Power AL12-F60 on mine and my new mechanic has filed a 337, it's not approved yet but he doesn't think it will be a problem.

Just in case it helps someone else, the STC for the motor conversion came with a VR600a voltage regulator. My previous mechanic did not ground the voltage regulator with a separate wire, instead assumed that the bolts would do the job. Unfortunately it didn't occur to him that since the nuts were insulated by the firewall insulation and the VR by rubber stand-offs it wouldn't affect a very good ground. I experienced an intermittent spike issue on the amp meter. Grounding the VR case properly took care of it. The Plane Power alternator grounds through the case to the motor, I grounded the VR straight to a ground strap nut on the alternator case, no more twitchy amp meter.

[GAHorn]

... Isn't it a shame it is so difficult to bring our airplanes out of the 1950s.

Some of us acquired our 1950's airplanes because we LIKE the 1950's.

[Dooley]

Thanks I'll make sure its grounded. I guess I was just lucky with my old voltage reg as it didnt have a dedicated ground.