robotronski

Anybody ever see or hear of a Caliber 5 with the OS 52 4-stroke power plant??

Saw a listing on a dealer site for the OS 52 (heli-specific model)

I've seen many an O.S. 4-stroke on a plane but never on any heli.

O.S. does in fact produce a .52 engine specifically for heli installation.

Any advantages/disadvantages??

Well, if you know something let me know. ThanX

BarracudaHockey

My Feedback: (11)

Its been tinkered with but the consensus is that the smaller heli's arent geared correctly for the power band of a 4 stroke. Might be an interesting project but it would be a lot of work for marginal performence, the Nexus Legatto 4s even with 30 percent fuel, and the engine leaned to the verge of burning up, could barely get out of its own way.

Cyberfyn

A 50FS in a 30 size heli would make a pretty stable platform. No hot ship though, but in the bigger Caliber-5? Like Cuda says, the FS engines are only realy suited for high torque situations like direct driving big props. The gearing is all wrong for the powerband of the four stroke engines.

Ian F.

robotronski

Thanks for the quick input guyz.

Now I understand why you don't see that setup at all.

Sounds like the 4-stroke powerband is not ideal for the 50 size heli.

I would be willing to bet it would have had an interesting sound while flying though.

Cyberfyn

The Caliber family are a LOT quieter than other helis due to the belt drive setup, but I know what you're saying I have an FS-91FS-IIP in a 76" Extra300 and it sounds a lot better than the screaming two strokes. In helis I love the sound of the Century Predator Gasser. Plus it runs for like 30 mins on one tank and uses regular pump gas with a splash of oil

Ian F.

BarracudaHockey

My Feedback: (11)

I found an annoying and dismaying fact yesterday. Someone showed up with a caliber at the field and apparently the damn links arent adjustable, that you have to buy a linkage upgrade kit or your stuck with the geometry you get from the factory links, made me think I was back when the only way to reverse a servo was put the arm on the other side.

Cyberfyn

Yeah, it's Kyoshos idea of idiot proofing the machine. I replaced all my links for the Rocket city style when I was having probs. Only found out they were not adjustable after spinning the damn ends for half an hour though

Ian F.

BarracudaHockey

My Feedback: (11)

Um......yea, btdt. Thankfully a previous Caliber owner showed up and filled me in or I could see the 10 minutes I spent tinkering turning into 30.