This probably sounds like a ridiculous question, and my guy feeling is "No", but I have to ask. I've got an operational Hirobo Shuttle that I won't be using (since my experience in aerial RC is nil) so I'd like to salvage as much as possible from the Heli and mount it into a small glow engine plane. The Heli engine is a glow plug engine and is probably a .30-.40 size (not sure, the plate is hidden by the Heli's frame). I'd really like to use it, if at all possible for another project. I'm already stripping the servos for use on my Senior Falcon.

Does anyone have any experience performing this kind of "graft" ? Can it even be done? (I know I'll have to take apart the housing b/c the heli uses a toothed band for starting, but is the engine at least similar underneath?)

G'day A friend of mine used to fly a plane with a heli engine. It was not modified in any way but you may need a prop driver and prop washer and nut from a similar plane engine. Heli engine are usually designed to run at high revs constantly and so you may need to experiment with props to find a suitable one. For a 30 size engine a 9 x 6 would probably be a reasonable starting place - for a 40, a 10 x 6. Heli engines usually have larger heads for better cooling but my friend did not modify the head of his engine at all. The heli muffler may also not be the right shape to use in a plane.

Why not sell the helicopter as parts or whole and use the money to buy a more suitable engine? I think you can sell things here or there are always other ways.

All the best

Mike from Oz

I think the shaft might not be long enough to mount a prop perperly.
Other wise i would had mounted a .25 car engine rated at almost 2HP on an airplan.

What stopped me was the high RPM. @ 30000 rmp..it'll rip the prop apart.

As memtioned above..threads are on the out side of the shaft for airplane engine
The threads are on the inside of the shaft for a heli.
If my hand and life depended on it...I wouldn't risk it.
I've had clutch bells come loose on my nitro car many times. The little screw
that presses against a washer to keep the clucth in place will come loose.
If a clutch comes loose..it's not life threatening.

Another thing to take into consideration is..you'll be replacing props more often. Once you mount
the clutch..it usually stays mounted unless there's a major problem.
All i know is...I get better torque with a wrench than a screw driver.

I havn't really consider it becuase heli engines are more expensive than planes engines.lol
Plus taking my heli apart...would make it less vaulable just to see if the shaft is long enough.
Car and heli use a clucth bell...so I figure it'll be short.

Heli engine also has a longer stroke (longer rod) than an airplane engine for more torque.
So...you can't really compair them to an air plane engine.

I had a shuttle once. I also horse traded it for a couple of nice .40 and .60 model built and complete....engines and servo..less RX.
Becuase the servos the heli wasn't standard and the gyro and what have ya.

What heli engines are you talking about??

The engines I've had are identical to the plane engines, except for the head and the carb (larger head for heat dissipation and a better carb). I've never seen a shaft with threads on the inside! The OS 50SX-H even came with a drive washer. The OS 37 SZ-H doesn't come with a drive washer, but you can just use the OS 32 SX drive washer for it. In fact, I had to buy the 32SX drive washer for my 37 to install it in my Venture 30 heli, since it required it.

As long as you have, or can get a drive washer and an airplane muffler for your heli engine, you should be able to use it in a plane.

Many use heli engines on airplanes, with the addition of the drive washer and a suitable muffler. The biggest trouble most encounter is an excessively rich midrange due to the heli carb being optimized for more or less constant speed operation with varying loads (the engine always spins about the same speed, but the torque is varied). Some can be tuned out, but it'll likely be there anyway. Not a real problem, just the engine will likely "burble" more than usual at about 1/2 throttle.

J

Actually the crank shafts are a bit shorter. If you can safely get a thrust washer, prop, washer and prop nut on there you're fine. Other than that it will work pretty much the same.

I don't think it's going to be long enough, because there's a spacer between the prop and the bearing for an airplane engine.
This way the prop will clear carb and thottle arm. You can add a small OD washer so the washer will only press against the bearing's
inter race then add more more washers..but damn the prop is going closer to the needle valve. and the throttle linkage is going to be
a little wickage or not at 90 and 90.

Keep in mind the prop will also flex back and forth from changing rmp

You might be able to put the nut on it with a thinner prop washer...but if my life depended it..sometimes I even double nut the prop nut.
Prop have been known to fly on me during start up

Even if you can get a nut on, it'll be border line, and a spiner is out of the question.

My life is worth alot more than $60.

From OS website FAQ.

Can I use a helicopter (-H) engine in an airplane? Why or why not? What muffler should I use?

The large cooling head on heli engines often provides too much cooling for the high-airflow application of an aircraft. Occasionally in a tightly cowled scale design a heli engine may be preferable to resolve cooling concerns. If the engine is produced in both forms (heli and aircraft), then the aircraft exhaust can be used on the heli engine and vice versa. Under no circumstances should an aircraft engine be installed in a heli application without a heli head or other extensive cooling precautions taken.

Well, I pulled the engine on the Heli. It wasn't the easiest thing to do, that's for sure. BUT i'm glad I did -> once I got the engine out I realized that what I THOUGHT was the throttle engaging was actually only the THROTTLE CABLE CONNECTOR spinning loosely around a VERY stuck throttle control rod! That would have been fun to crank up! (I would have thought I was @ 0 throttle and I actually would have been at somwhere between 25%-30% open!!!!!)

The markings on the side read "0S MAX", so I know the brand, but just not the size..... Any clues on this one? (UPDATE: I found the size stamped into the opposite side: 28 so I guess it's a 28ci)

I measured the shaft and it's 22.5mm (threaded portion) / 29mm total. I'd sure like to be able to use this engine if possible, but I can definitely appreciate the wealth of "... I didn't think of that......" scenarios!

UPDATE and Question: Here's a little something strange: The WEBRA engine I have has a "low speed needle" on the side of the muffler.... the OS MAX only has a "high speed needle"..... Am I missing something or are these OS MAX Heli engines supposed to be designed without a "low speed needle"? I guess they will run a little funny in planes.... [:-]

Any ideas or insights?

If you look into the hole in the centre of the throttle arm, you'll see a small flat head screw in there. That is the LSN. This is typical of modern glow engines with 2 needle carbs.

J