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.
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
Displacement: 0.91 cu in (14.9 cc)
Bore: 1.09 in (27.7 mm)
Stroke: 0.98 in (24.8 mm)
Practical rpm: 2,000-16,500
Output: 3.55 hp @ 15,500 rpm
Weight (w/o Muffler): 21.3 oz (603 g)