O.S. Engine OSMG1977 91HZ-PS 3D Ring Helicopter Powerplant  [OSMG1977]

Performance Overview of the O.S. Engine 91HZ-PS

The O.S. Engine 91HZ-PS 3D Ring is built for pilots who prioritise consistent power and tight throttle control during advanced 3D flying. Its engineering focuses on reliability under aggressive manoeuvres and steady mid to high RPM response.

Precision Fuel Management and Stability

A redesigned horizontal regulator combined with the PD-08 fuel pump provides a steady, predictable fuel feed in varying flight attitudes. That setup helps prevent fuel interruptions and keeps engine response linear when demanding rapid collective and yaw changes.

Torque Balance and Vibration Reduction

The piston and crankshaft have been refined to cut down vibration while preserving strong torque across the usable RPM band. The result is smoother cyclic inputs and improved stick feel for complex routines.

Compact Cooling Geometry and Carburettor Insulation

The slim heat sink head design lets the engine sit neatly inside tight cooling shrouds for effective heat dispersion. The supplied 61B-PII carburettor includes a thermo insulator to reduce heat transfer and stabilise the fuel air mixture under load.

This O.S. Engine 91HZ-PS 3D Ring suits advanced pilots wanting a reliable, tunable engine for precision 3D flying. Its balance of power, cooling compatibility and fuel control makes it a solid option for competitive builds.