WHAT IS THE DIFFERENCE BETWEENANEVOLUTION .52 NX AIRPLANE ENGINE AND A .52 EVOLUTION HELLICOPTER ENGINE?I HAVE A CHANCE TO BUY A HELLI ENGINE AT A GREAT PRICE BUT I WOULD LIKE TO KNOW IF IT CAN BE USED ON A .40 - .60 HIGH WING TRAINER. iS THERE
ANY THING ABOUT A HELLI ENGINE THAT WOULD RULE IT OUT FOR AN AIRPLANE?

I believe the crank is different because of the way it hooks up to the heli, and the cooling head is bigger. That's the extent of my knowledge on it and don't know if it would be ok to use on a plane. It might cool too well and not take a prop?

Some of the heli guys in our club break in their heli engines on fixed wing aircraft.  I don't know if they all will modify or work,  but these guys seem to be able to.

CGr.

in most cases heli engine have a shorter crankcase and a differant muffler and a bigger head fins. For the shaft you may have have to put the engine mount on shims, as for the muffler that can be changed easily if it's in the way, So chek the muffler, if it cost prohibitve to change the muffler it may not be such a hot deal, but if youe like me and have 3-4 spares sitting around its probably a great deal. I've put plenty of buggy motors on planes and those are pretty close to heli engines.

The carbs are optimized for mid range in many cases
The heads are bigger for cooling
The crankshaft is shorter for mounting a clutch/fan (not the crankcase, the crankcase is identical)

The nusance is getting a prop drive plate, spinner back plate, prop, washer, and prop nut on the short crankshaft.  Everything else is pretty much the same.

This is the Heli engine http://www.horizonhobby.com/Products...odID=EVOE0520H . Note the MUCH larger head. It also has a different carb. Here is the manual http://www.horizonhobby.com/ProdInfo...eli_Manual.pdf which gives a closer view and a list of parts. You'll note that there is no "prop driver". This is because in a heli the shaft connects to a clutch. This is OK short term for break-in but you wouldn't want to run this way long term. Fly a plane engine in a plane.

Pass on this engine unless you see a heli in your future.

Pass on that engine if you do have a heli in your future.

Basically the difference is the cooling head.  It is larger on the heli because there isn't that much air flow going accross it.  Also in the box it might be missing the prop nut and washer.  You will need these to break in the engine with a prop. 

I would say to pass on this one because in an open area it may not come up to temperature.  If you end up with an in-cowl situation where you end up overheating this might be a decent solution instead of hacking open the cowl further.