Franklin 6A8-215-B8F on a 172?

[alaskaflyer]

Franklin conversions in a 172?

I'm looking at a Franklin conversion in a Cessna 172D. Some are listed as "220 hp" while this one is listed as a "215 hp."

I assumed that the only Franklin engine installed in a Cessna was the 6A-350, which I have only seen rated as 220 hp. The only 215 hp Franklin I could find on the 'net was the 6A8-215-B8F, which is a much heavier, older engine. Surely that isn't installed in Cessnas?!?

Any advice on the discrepancy? Or on Franklins in general? The modern STC includes a gross weight increase and I wonder if the original STC did also or am I looking at a loss of useful load? I'd be interested in CG problems or actual stories regarding parts availability. Thanks!

 

[Tom-D]

Re: Franklin conversions in a 172?

I'm looking at a Franklin conversion in a Cessna 172D. Some are listed as "220 hp" while this one is listed as a "215 hp."

I assumed that the only Franklin engine installed in a Cessna was the 6A-350, which I have only seen rated as 220 hp. The only 215 hp Franklin I could find on the 'net was the 6A8-215-B8F, which is a much heavier, older engine. Surely that isn't installed in Cessnas?!?

Any advice on the discrepancy? Or on Franklins in general? The modern STC includes a gross weight increase and I wonder if the original STC did also or am I looking at a loss of useful load? I'd be interested in CG problems or actual stories regarding parts availability. Thanks!

The type certificate says:

Engine

Continental C145-2 or -2H (See Item 112 for optional engine)

Or note 112:

112. Continental O-300-A engine (Same limits as for C-145-2 or -2H engine)

ANY other engine must have PAPER to approve the installation.

SEE THE LOGS. how and when was it installed.??????

 

[Dave Krall CFII]

Re: Franklin conversions in a 172?

I'm looking at a Franklin conversion in a Cessna 172D. Some are listed as "220 hp" while this one is listed as a "215 hp."

I assumed that the only Franklin engine installed in a Cessna was the 6A-350, which I have only seen rated as 220 hp. The only 215 hp Franklin I could find on the 'net was the 6A8-215-B8F, which is a much heavier, older engine. Surely that isn't installed in Cessnas?!?

Any advice on the discrepancy? Or on Franklins in general? The modern STC includes a gross weight increase and I wonder if the original STC did also or am I looking at a loss of useful load? I'd be interested in CG problems or actual stories regarding parts availability. Thanks!

It probably wouldn't be a problem for you as a sole user of the converted plane but it was for some of the pilots in our club a few years back who, even after being properly checked out in the slightly nose heavy 220 HP SkyHawk, landed it too nose heavy enough times to cause enough repair bills for the owner to take it off the flight line permanently.

 

[poadeleted20]

Re: Franklin conversions in a 172?

I assumed that the only Franklin engine installed in a Cessna was the 6A-350, which I have only seen rated as 220 hp. The only 215 hp Franklin I could find on the 'net was the 6A8-215-B8F, which is a much heavier, older engine. Surely that isn't installed in Cessnas?!?

Have you checked the available STC's on the FAA web site for a C-172D? If there is one for the 215HP engine, it's technically OK, or the FAA would not have STC'd it. If there isn't, it will cost more than the airplane's worth to get it field approved (I know several people who've STC'd and field approved engine changes). Of course, the existence of an STC just means it works, not that parts are available, so research that with the folks whom your mechanic uses to supply parts where you are.

 

[alaskaflyer]

OK, found that the plane actually has the "common" 6A-350 conversion.

Apparently the discrepancy in HP is due to different STC's being issued for essentially the same mod but to different companies (or different iterations of the same company) over the years. Some listed the horsepower upgrade as 220 hp, some as 215 hp. Either way, better than 145 hp!

Plane was almost sold last week but then the buyer couldn't perform and the guy called me up yesterday and said it is available again. We'll see...I'd love to change my signature below.

BTW, I've been looking for a 170B for a while, but insurance on a 170 is about $900 more than a 172, and prices on 170B's with HP increases are out of my range. I would like to do some ski work (and light off-airport stuff in the summer) but for the money I am considering a 172 with some mods instead. Airglass says that they are likely to receive STC approval in the next two weeks for their heavy duty/over sized nosefork assembly for all 100 and 200 Cessna models, which would enable me to install 8.50 tires all around, and then there is always the nose ski...