Franklin engines??

I have been researching engines for my exp Super Cub. Has anyone installed a Franklin engine in a Super Cub? They are 6 cylinder and require a bed-type engine mount, and can be had up to 220hp for the same weight as an O-320 or 360 Lycoming? I know the Franklins were used in helicopters and in Stinsons for years. The Franklins are getting some attention in the RV-x groups so that got me thinking about one for my project.

Thanks,
Todd

Hi Todd,
I think the Franklin 220hp sixes weigh at least 330lbs, quite a bit more than an O-360. That would be the deal breaker for me unless you wanted to make a "Sherpa" type of Cub.

I sure like the sound and smoothness of Franklins though. Nice engines.

Todd, A friend has a 115hp Franklin in an experimental Aronca 7ac. It doesn't cruise
much faster, but climbs like a 180hp Supercub.
He's had zero problems with it. I wouldn't be afraid of one

Tim

Todd-- I have a 220 Franklin powered 172 an Edo 2440's. It is a VERY capable floatplane and I have had zero problems with the powerplant. Burns 13 gals per hour at 75 % power. I also have a 150 Hp Super Cub. Hmmmm !!!!
STEVE J

I don't know what they weigh, but don't see why the 220 Franklin would weigh so much more than the 180 Lyc. The 220 Franklin is only 350 cubic inches, gets it's horsepower from high rpm and high compression. Haven't heard that the RV'ers are getting into Franklins, they seem like they are almost all fitted with 320,360 or (now) 390 Lycomings. Never seen a Continental on an RV. Seen big (6 cyl) Lyc's on the Harmon Rockets but never on an RV proper.
The Franklin has some cool features, like replaceable steel liners on the cylinders and a crankcase trapdoor on top for a peekaboo view of the lower-end.

Rooster

I know a fellow who has the 220hp. model Franklin in a C-170, its one of the best performing 170's around.
Because of the length of the 6 cylinder I'm Not sure about the practical application in a Cub and still trying to retain some cg. A lot of the 0-360 seem to be a little nose heavy, stick some more length & weight on the nose and you'll compound the problem.
However if you're not landing on the rough stuff, w/ big tires, the extra ponies should help a heavier plane or on floats. For every change [mod] there always seems to be something else effected, if you do put more weight on the nose, you could next try to some forward gear to try to fix the cg issue.

I saw a PA-12 at Surfside with a radial motor last week. I don't know the specifics but some of the folks flying it said it was a blast.

I have flown the 180 Franklin on an old Stinson. It would climb just like a C-180 with comparable load, but cruise was a 14 gph disaster. It did do a spectacular aileron roll, and was easily the best looking aircraft in town. Its replacement was a 180hp Decathlon, and I love every minute of it. The Cub is way more fun in the pattern, though.

bob turner said:

It did do a spectacular aileron roll, and was easily the best looking aircraft in town. .

Click to expand...

Ditto to the aileron rolls and good looks, did good Barrel rolls too! Though it had the F-150 good smooth engine, but hated 100ll, stuck valves with that almost guaranteed. I sure miss her ..... the one in the photo. <------

There used to be an experimental Supercub I'd see every year at either the Evergreen Fly-in or the Arlington Fly-in (forget which one....), as I recall it had a 540 Lyc shoehorned into it. It was based at Sandy Oregon.
Never saw it fly.

Look into the 180 HP Jabaru 8-cylinder engine. ...Clyde Davis