OS. Speed 91HZ-R, for 3C (18641) (Graupner 2788)
For T-rex 700 and Raptor 90 size helicopters
Designed for precision aerobatics!
Following the popularity of the 91HZ-R with On-Demand Regulator, O.S. has now taken high-performance, high-speed helicopter engines to the next stage of evolution. Introducing the 91HZ-R Speed Engines - based on the 91HZ-R, factory-tuned at the O.S./Japan facilities and guaranteed to blow you away! The 3C version is designed expressly for F3C competition with its controlled, precise maneuvers in mind. For pilots who prefer aggressive, stick-bashing 3D flight competition, O.S. offers a 3D version.
Achieve faster flight speeds and improved hovering stability.
Lightweight, machined heatsink head
Big-bore carburetors best-suited for the intended use (F3C or 3D)
Best precision advanced exhaust cylinder timing (for F3C or 3D)
Newly designed combustion chambers, shaped to match the big bore carburetors and advanced exhaust cylinder timing
Lightweight, forged steel crankshaft counter weight to lower vibration for higher speeds
Improved backplate shape, to accommodate Futaba's BPS-1 RPM Sensor and increase primary pressure for greater stability
Stock Number: OSMG1980
Displacement: 0.91 cu in (14.9 cc)
Bore: 1.09 in (27.7 mm)
Stroke: 0.98 in (24.8 mm)
Output: 3.6 hp @ 15500 rpm
Practical RPM Range: 2,000-16,500
Weight (w/o Muffler): 21.2 oz (603 g)