Hi there, i have a brand new OS 108 FSR that will like to use if possible on a world models ultimate bipe arf 120R, and im not sure if it will be enough of not? If it will be overpowered or underpowered, so im submiting both items specs and will apreciate any advice.
I dont know how to interpret and translate very well the engine specs or requierements.
World models ultimate bipe arf 120r:

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Specifications
Wing Span : 53.5 in / 1360 mm
Wing Area : 989 sq in / 63.8 sq dm
Flying Weight : 9.9 lbs / 4480 g
Fuselage Length : 56 in / 1400 mm
Engine Required : 4 stroke 1.20 engine
:
Radio Required : 4 channel radio w/ 5 servos

OS 108FSR:

SPECIFICATIONS:

Engine Type: 2-Stroke
Displacement: 1.080 cu. in.
Cylinders: 1

General Specs:
- 1 cylinder
- Displacement: 1.080 cubic inches
- Bore: 1.140 (in.)
- Stroke In: 1.060 (in.)
- Shaft: 3/8 x 24 threads
- Low RPM: 2000
- High RPM: 16000
- 3.000 bhp @ 16000 RPM
- Weight (no muffler): 26.50 oz.

Applications:
- Giant

Street Price:
$249.99

WILL THIS PLANE AND ENGINE BE ENOUGH FOR EACH OTHER?
Thanks

Should be plenty,mabe not unlimited vertical but should fly it plenty good.

Could i add a sullivan smoke pump with a pits muffler and obviously the smoke fluid tank? Engine will still be enough to pull the extra weight?
Thanks.

The WM 1.20R is rated for a 1.20 FOUR STROKER....

So your 1.08 two stroke engine should outperform the stock configuration by a good amount once properly prop'd.

The 1.08 engine is roughtly the equivalent of a 1.4-1.6 four stroke engine in terms of power.

Yes no problem, just don't be tempted to add a large smoke fluid tank.

Keep your smoke usage on the "light" side ( it is MUCH more dramatic to kick it in on occasion ).

Because you are using a two stroke the engine will rev higher and hotter than a four stroke engine, so using a smoke pump will be less problematic.

I once had a Dave Patrick Ultimate with an OS 108 in it and it did just fine. Run a Slimline pitts muffler. I would however suggest not adding ANY extra weight. I don't remember what mine weighed but Ido remember that anything more and the 108 just wouldn't cut it. I ran a 2 servo setup for the ailerons and linked the upper and lower ailerons with a pushrod. Worked just fine and eliminated 6 oz. Use an APC 15X8 prop.

No problem, that os 108 is a real stump puller.

I would go with the 16x6 on that engine to handle the smoke pump weight.