Lycoming O-340

[170C]

Years ago I considered purchasing a members 170 with a Lyc O-340 & cs prop. We never got together on price so I went on down the road. Later a 170 member told me that I was probably lucky as that engine was sort of an orphan engine, not really very popular and parts might become an issue. I now have a good friend who has sold his 182 and is looking at 170's. There are lots of them out there for sale and one of many he asked me about has a LYC O-340 on it. I first told him what I had been told, but got to thinking that there must be a lot of expertise among our members regarding that engine and I would like to tap into that expertise so I can give my friend (and hopefully a new C-170 member) some facts to consider regarding this engine. Please give me some input.

Thanks,

Frank

[Mayday]

I don't have a 170 or a O-340 but from what I understand, the 340 is a decent engine, the problem comes with the prop. The only prop certified to be used on the 170 with a O-340 is a C/S prop with a hub that has an AD on it requiring frequent inspections for cracks or corrosion I don't remember which. I remember seeing a few 170's with the O-340 at shockingly low asking prices, turns out they either needed a prop or that prop hub was due or near due for the AD inspection and the owner knew it probably wouldn't pass.

[Bruce Fenstermacher]

The engine was designed and used on what turned out to be a small run of Beech aircraft and the type was not used anywhere else. So as it turns out the model had a limited run and has a limited market so some parts are also limited. It does share a lot of parts with other engine models so not all parts are hard to get.

I have a friend who has one in a Beech which he overhauled and while he'd rather not have it, he does not seem particularly worried about it.

[blueldr]

I think one of the main problems with the conversion to the Lycoming O-340 engine was the cost versus the small horsepower increase. You might be able to find a cheaper engine but the conversion cost would be she same as for an O-360 without the limiting propeller problem.

[170C]

Thanks for the input. I think I have sufficient info to steer my friend away from this engine.

[DaveF]

Good idea, Frank. Neither the engine nor the prop would be easy to own. One unsupported STC, one approved propeller, and one unsupported engine. Run away!

http://www.cessna170.org/forums/viewtop ... 173#p32173

[DaveF]

Right now there are three Doyn O-340 conversion 170Bs listed on Trade a Plane. They're either not so rare or nobody wants one.