O.S.Speed 91HZ-R 3D Helicopter Engine

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.  Features: Lightweight, machined heat sink head Big-bore carburettors 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 back plate shape, to accommodate Futaba's BPS-1 RPM Sensor and increase primary pressure for greater stability The cover plate has a cell to accept a sensor designed to install in the cover plate from Futaba GY701 / CGY750 Governor Technical Specifications: Displacement: 14.95cc Bore: 27.7mm Stroke: 24.8mm Output: 3.6ps/15,500RPM Practical RPM Range: 2,000-16,500 Weight: 603g Package Includes: Engine Pack O.S. Speed Tuned .91HZ-R Heli