Anyone fitted an alternator to a franklin engine

Bernie Ferrie

Bernie Ferrie

New member
Guys,
I was looking at my 165 hp Franklin engine last night and recall reading about some one making an Alternator for it.
Has any one done this? What are the pros and cons - and where can you get them?
I'm just a bit sick of the old gennie with not much juice to power 'stuff'.

Seeing I'm rewiring I may as well go the full hog.

I hate putting two questions in one posting but....... I figure this is only one and a half.

Very interested in how folks have wired up their aircraft and what mods they have done..

Thanks in advance

Bernie
 
Bernie, I believe the original generator for the 165 Franklin was rated at 25 amps. "I've been told" that this generator can be rewound to produce 35 amps, which should be sufficient on most aircraft. However, I've seen alternator conversions available from Bruce Kown in Georgia. His e-mail is c.aire@mindspring.com. His phone number is 770-386-7435. Georgia is on Eastern Daylight time. I've done business with Mr. Kown, and have found him to be reliable and honest. Dan
 
It would be nice if someone did, Dave. I searched, called some places, but either got a laugh or a "no" when I mentioned the engine. There's something for the O-435-10 or 11...I forget which, as well as some of the others, but the accessory case for the A series is different as I discovered the hard way. Why this would make such a difference I do not know, but my understanding is at the level of the "Don't all the generators have little whirly gears that turn them that are the same as the other whirly gears in other generators?"

Seriously, the only mod I have direct knowledge of to increase amp output is one former Triple Tail owner Jan Gerstner used on the 14-19 he owned for 29 years, and regularly flew into the Idaho backcountry, of all places: having the armature rewound, as others have suggested in the Franklin generator/alternator topic. He said he managed to get it to generate 50 amps this way. He is a very precise and credible fellow.

As usual, I hope I'm WRONG and someone has found something that will indeed suit your needs. I considered having the armature treatment done on mine during it's MOH, but mine was undergoing repair, not restoration, and that sort of thing was third or fourth priority at that time and still is.

Jonathan
 
[At the Columbia Fly-in Dan Torrie mentioned that he had installed an alternator on a Cruisair a few years ago.He said that they had to do some machining to make it clear the motor mount. This was because it was intended for a stinson and didnt quite fit.The original STC for the alternator was from Stan Bedford and was only for the Stinson. A Stinson mechanic told me recently that the original alternator for the Bedford STC is no longer available and that any sold recently are for experimental use only since the numbers dont match the paper work. Dan Cullman,s recommendation of Bruce Kown as maybe the only person who might still be able to supply the right one is correct but there may be another source for a different alternater. This week I noticed an add on Barnstormers for light weight alternators (B&C Alternators) and I called and talked to them. They have an amazing number of STCs for old planes but none of them are Franklin powered. The man said there hasnt been any demand for them. He said that the Franklin generator is a standard bolt pattern but he didnt know about the coupling . I asked him to FAX me the shaft size of his units so I could see if our gear and coupling could be machined to make it work. It should be a lot easier to get approval of an previously approved unit with only a few small changes than it would be to start from scratch. Looking at the photo in his add makes the unit seem to be about the size of a cottage cheese container. I am waiting on the info and pricing right now.Maybe if we could get enough orders the owner might get the approval . If it cleared both the Bellanca motor mount and the Stinson mount there might be a good market for it. I will keep you posted when I get more info. Take a look on Barnstormers! Grant/quote]
 
]I finely got a drawing from the B&C alternator man and I dont know if things will work out. Could someone help me by measuring the outside diameter of a Franklin 15 amp generator? I only have 25 amp units handy to measure,and they wont fit the Bellanca motor mount without some modification.If the owner can supply an alternator that will fit all Cruisair motor mounts and hopefully all Stinson then he will be more inclined to try for a multiple STC. He said that he has had very good luck dealing with the FAA on getting STCs. He allready has many approved units.I am going to keep plugging along on this. Grant.
 
Grant,
Great work, unfortunately I only have the 25 amp gennie, but I have my engine out of the aircraft and sitting in the engine mount on a stand, and looking at the clearances the 15 amp gennie would have to be half an inch less in diameter than the 25 amp to clear an unmodified engine mount. I measured the amount of metal cut out of my engine mount for the modication and it was o.4 of an inch. Hope this helps

regards
Bernie
 
I just noticed an add on Barnstormers for a 45 amp alternator for a Franklin. It was $400. and was brand new. No mention of paper work but it is worth investigating. I am spending all of my money on an annual right now, or I would buy it. Grant.
 
I will measure my 15 amp generator and get back to you, Grant.

I might be interested in an alternator for a different reason. I get a lot of interference noise on my radios, such that it gets really difficult to hear. A friend suggested that the problem might be that the old generators are "leaky". Does (did) anyone else have a problem with this? I don't remember it on my other (past) Cruisair with the 25 amp gennie.

Might there be any easier solutions than an alternator?

All comments welcome (except maybe that I am too short, too bald, or whatever)! Thanks!

Mike in NH
 
Hi Mike, I was able to locate a 15 amp gen to measure,but thanks very much for the offer.I wish I didnt hesitate on the alternator that was for sale on Barnstormers because it sold quickly. I hope it was a Bellanca guy that got it. Maybe we can still get some information on it.(HE WHO HESITATES IS LOST). I should have remembered that old adage. Grant.
 
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