Heli Engine in airplane?

[DethWshBkr]

Any reason this would not work?
I just built up a Thunder Tiger X50, and ordered an RL56 from Tower, but then decided to get a YS56 for the X50. I have not yet sent the RL56 back, and I am curious to see if there are any issues with putting it into an airplane. I can't see any real problems, as I assume the head should be able to cool properly since it is exposed, and it should be more than ample power.

I am tempted to so the way of SkunkWorks, and build one up from nothing....

[Kington99]

does it have the necessary thrust bearing surfaces on the crank? heli engines experience negligble axial thrust, plane engines take the entire motive force as a thrust on the crank thrust surfaces, I've no idea if they design them differently or not but it's a potential failure

[Canuk]

I don't think you will be happy with it as the carbs are made to do different things the way they run.

[memosteve]

Engines designed to be in helis differ quite a bit from plank engines:

Heli engines are ran in environments where cooling is less adequate than an airplane application. Because of this, heli engines are designed to run rich on higher nitro/oil content fuels to help cool the engine, thus ensuring the motor stays running. Airplane engines are designed to run leaner and with fuel that's lower in nitro/oil content as the engine can rely more on convection cooling.

The other big difference is in the carb design:

Carbs designed for heli applications are design to specifically run efficiently at constant mid to high throttle settings...by design, they aren't as efficient at constantly changing from low-mid-high positions, such as you typically find in airplane applications.

[puggster]

the only real problem i would think could be an issue is the load on the bearings, i thought the prop shafts were slightly difrent on helis, heli engines are much like nitro car engines, the bearings arnt really designed for load on the prop shaft, or in the heli or car's case the crankshaft,

typicaly i cant see why it wouldent allow pull from a prop, but could, experience premeture failure in the bearings,

if these could be swaped out from an ic plane engine then i think it would fair better,

the other potential problem would be deadsticks at low rpm, heli engines run at faster rpm, as we know the prop will reduce rpm and increase load, there may be issues with over proping, tuning might be a issue, and could lead to deadsticks in idle,

i think the rpm in idle on a heli is far greater than on a plane,

i think there may be some challenges, certainly do-able but could prove a headache

[MXRACERX43]

I know two friends who used OS 50 Hypers in planks and flew the hell out of them! Both flew great.

No reason at all you cant use one

[Pinecone]

There are few issues to deal with.

1) The large finned head can mean over cooling on a plank.

2) No prop driver and typically a short crank nose.

Solve those and have fun.

[seanh]

I know it's been done enough that if you can fit it in and secure the prop it will fly. The only thing I'd look at is prop size.

Airplane engines run at a lower RPM than the Heli engines do. So, you'll be responsible for finding a prop that will work that engine RPM range. For example. My OS 91FX runs between 7500K and 10K. According to OS, I need to run this engine in the 10K range for optimum power. On a 90 heli engine I think that engine RPM is closer to 15,500. You can see that that RPM difference of 5K is significant.

what would be cool is if you could gear it down a bit.