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

Overview of the O.S. Engine 91HZ-PS 3D Ring

The O.S. Engine 91HZ-PS 3D Ring aims to deliver repeatable power and smooth throttle response for advanced 3D flying. The design supports controlled performance during complex manoeuvres.

Fuel Regulation Designed for Aggressive Flight

The updated horizontal regulator together with the PD-08 fuel pump ensures consistent fuel delivery in vertical and inverted attitudes. That reliability reduces in flight trimming related to fuel supply variations.

Engine Balance and Reduced Resonance

Refinements to the piston and crankshaft reduce resonance while maintaining torque throughout the rpm band, which improves handling during precise stick work.

Compact Head Profile and Thermal Protection

The narrow heat sink head is easier to install within modern cooling shrouds while still providing effective heat transfer. The 61B-PII carburettor is fitted with a thermo insulator to help keep the mixture stable under heat load.

The O.S. Engine 91HZ-PS 3D Ring is a strong candidate for pilots seeking a stable, tunable engine for advanced 3D flight, offering a balance of power delivery and thermal control.