O.S. Engines 91 HZ-R 3D speed helicopter engine is eesigned for all-out 3D competition. 165º exhaust timing for optimal horsepower and stable hovering. Newly designed combustion chamber shaped to match the big bore carburetor and advanced exhaust cylinder timing. Big Bore carburetor is designed to develope stable horsepower at 70-80% throttle which is widely used in 3D flight.
Fuel: 10%-30% nitromethane with at least 18% lubricant. Lubricants may be either castor or synthetic oil or castor/synthetic blend.
Field Equipment: glow starter, fuel bulb, fuel can filter, fuel pump hexagonal starting shaft (depending on brand of helicopter) electric starter, battery and fuel tubing
Muffler-Depending on heli
Displacement: 0.91cu in (14.9cc)