O-360 generator to alternator conversion

[ksaccounts]

I have a 1952 Cessna 170B with a Lycoming O-360 conversion. I'd like to convert it from generator to alternator. Does anyone know of an existing STC that covers the conversion for the 170B? How about examples of 337s that would cover this? I've seen some 337s that apply to the original 145 HP engine, but haven't found any for the Lycoming O-360 as instolled in a C170B. I'd rather not reinvent the wheel. I know that there are lots of 170Bs with O-360s that have alternators. Anybody got any idea how I can do this? My mechanic says the Seattle area FAA is not very field approval friendly. That's why I'm hoping someone knows of an existing STC to do the job. I've checked with Plane Power on their conversion kits and they say they know it's been done, but they have no specifics on how to get it through the FAA. Their STCs are all airplane specific, not engine specific. Any comments or ideas for me?

Bob at S36

[Roesbery]

Bought a factory new Lycoming engine in the winter of '80-81' and it came with a new alternator installed as standard equipment.

[GAHorn]

.. Their STCs are all airplane specific, not engine specific. ...Bob at S36

That's because the genertor or alternator is not an engine modification.... it is an AIRFRAME modification. It mattes not which engine is installed. Any of the alternator conversion STC's which are descriptive of the airframe/engine comibnation is allowable. Try Jasco, or simply convert via the Cessna alternator conversion.

[ksaccounts]

Thanks for the tips George. I guess that's my question then, anybody know of an STC that covers this airframe engine combo? C170B with Lycoming O-360 engine. Or, a recent approved 337 with this conversion? I haven't had any luck finding a Jasco conversion, or finding the Cessna alternator conversion. Someone somewhere must have been down this road before.

Bob @ S36

[n2582d]

Bob,
Who's STC do you have for the O-360? That is where I would start in looking for doing the conversion from a generator to an alternator. Other sources of advice would be Air Plains as they do O-360 conversions on C-172s http://www.airplains.com/index.php/cont ... ch-support or Del-Air at 559-784-9440.

Which model O-360 do you have? Del-Air's O-360 STC is very generic; it doesn't specify any specific O-360 model. So if you look at the TCDS for the O-360 you'll see that the C1A, C1C, C1E, C2A, C2C, C2E, J2A, and A series O-360s have alternators as standard equipment and generators as optional equipment. See page 6 and 7: http://www.airweb.faa.gov/REGULATORY_AN ... /E-286.pdf If you have one of these model engines, and your O-360 STC didn't specify a generator, it would only require a logbook entry to swap out a generator for an alternator in my opinion. This bulletin from Lycoming may also help with part numbers: http://skytecaircraftstarters.com/images/SI1154L.pdf

[GAHorn]

... See page 6 and 7: http://www.airweb.faa.gov/REGULATORY_AN ... /E-286.pdf If you have one of these model engines, and your O-360 STC didn't specify a generator, it would only require a logbook entry to swap out a generator for an alternator in my opinion. ...

I think that the alteration of the electrical system voltage regulator and required overvoltage regulator that alternator conversions have would qualify as a MAJOR alteration, and would require a Form 337, So the conversion would likely require more than a simple logbook entry.