Saw an add for a Stinson 108 with a Lycoming O-435 in it. Any advantage of this over The 165HP Franklin.

qmdv wrote:Saw an add for a Stinson 108 with a Lycoming O-435 in it. Any advantage of this over The 165HP Franklin.

I believe the O-435 started life as a helicopter engine. Tough engine, but getting hard to find parts for, and only one prop to fit it.

http://www.hangar9aeroworks.com/Stinson ... gines.html

Gump

Wasn't this a GO-435?? A geared Lycoming. I've run em on a few airplanes, and they are reliable, but as Gump says, getting hard to find parts for. The overhaul costs will bring tears to your eyes.

Commonly used in Widgeon conversions, as well as the GO 480.

MTV

Never heard of a GO-435 in a Widgeon, only GO-480's. Have heard of a GO-435 in a Helio, I think.
The O-435 was the standard engine in the Stinson L-5 "Sentinel". Not much horsepower (190) for the displacement, when you consider that the 470 Cont has 225 or 230 horse. The O-435 is a semi-common mod for the Stinson 108, maybe because (I think) the whole show off an L-5 bolts right on.
I believe that some Bellanca triple-tails had the 435 as the standard engine also.

Eric

Most of the stinson folks advise to stay clear of planes with that conversion. As stated one prop, expensive, and a heavy orphaned engine that cuts into the useful a lot.

Suggest not buying it. Good flying plane with it - I know, because that's been my source of killing retirement fund - but engine is hard to find parts for. Central Cylinders in Omaha did a good job of a rebuild, but I found my crankshaft from Shane Horton - who introduced me to this web site! -. Biggest problem is the prop - with the exception of a new one, there is only one that fits the engine when it is mounted on a Stinson - Hartzell 12 X 20 ... Varible speed hydromatic prop, and it has a 250 hour / 5 year AD on it, that cost me $1800 a year ago. There is only one replacement prop, that Hartzell is quite willing to sell you a brand new one, between $20K and $25K. Had I known now what I didn't know five years ago, I would not have bought my Stinson with that engine and that prop.

I wouldn't categorically pass up a Stinson with this engine on it if the seller recognizes the essentially negative value of the engine. If the airframe is in good shape and the price is right is might be a good candidate for a 165 retrofit or upgrade to a more valuable alternative. But that means you would offer in the neighborhood of 10-15k and it could be tough to convince a seller of the legitimacy of that value.

The earliest use of the Lycoming O-435 that I'm familiar with was on the Stinson L-5 in WWII. The erarlier aircraft through the L-5E used an
O-435-1 (12 Volt)engine, and the L-5G used an O-435-11 (24 Volt) engine,
the only difference being the starter and generator. They were, incidentally, mounted on the rear accessory case like a real aircraft engine
accessories should be.
The engine was also used on an experimental Primary Trainer for the Army (pre USAF), the XPT 25.
The only post WWII installations I can think of were the were the relatively limited production Johnson Rocket and the Bellanca Cruisemaster.
All the above used the direct drive model rated 190 HP at 2550 RPMat SL.

Thought I'd add to this old thread just for posterity if someone in the future should Google for this engine.

I run the geared GO-435 on my aircraft and as mentioned, they're no longer supported by Lycoming, and haven't been for years. There's a joint called Central Cylinders in Omaha that bought all the gearing, surplus parts etc and they are the biggest overhauler of these and many other geared engines. Parts are still quite easy to get hold off, but getting scarcer. The overhauls are very expensive simply because CC insist on tearing the gearbox down in conjunction. Now, you don't have to do that if the gearbox is in good shape, so you could bring the engine to another shop and get away with less. Problem is not many places still want to deal with the geared ones, so you're choices get slightly more limited. But there's still quite a few around. A good way to determine if the gearbox needs attention is to test the play about 4ft out on the prop - if it has more than 1" play, it's probably time.

The GO-435 is a pretty solid engine that is basically a 6-cylinder O-290. Most have low compression, so can be run on Mogas and were certified for 81 Octane fuel. Low compression also means longer lasting. The gearboxes have a reputation for being bad, but that's not really true. If you fly them right (positive drive and don't throttle jockey too much) the gearbox will outlast the engine. The GO-435 only has 1200 TBO, and that's a reflection of the way the engines were used by people used to flying direct drive engines. There's nothing inherent in the design that says they won't go quite a bit further if treated well.

qmdv wrote:Saw an add for a Stinson 108 with a Lycoming O-435 in it. Any advantage of this over The 165HP Franklin.

Tim- have very good experience with 0-435 's on Stinson 108 aircraft --- have good supply of spare parts for 0-435 and Stinson -Bellanca spares. Prop is short suite --three are several fixed pitch props available as well as the variable pitch Hartzell .

qmdv wrote:Saw an add for a Stinson 108 with a Lycoming O-435 in it. Any advantage of this over The 165HP Franklin.

I don't know but I assume that the O-435 in a Stnson 108 is an STC'd installation? Pretty impractical, I know, but just imagine a GO-435 of 240-260 horsepower on a 108 instead of the 190-horse 435. Wow!