Thunder Tiger Pro-39H delivers smooth power for sport and 3D pilots alike and delivers smooth power at your demand. With a displacement at .394 cubic inches, the Pro-39H is the largest displacement engine available in the popular 30-size helicopter class, and directly fits in all popular machines. Precision air bleed carburetor makes adjustments simple, and efficient mufflers keep things quiet at the field.
The Pro-39H works best in helicopters with gear ratios ranging from 9: 1: 1 to 9: 8: 1, and develops peak horsepower at 16,000 to 18,000 RPM.
XC2 (extreme composite coating) cylinder liner with special criss-cross pattern etched
High strength connecting rod with bushings pre-installed
One-piece crankcase with squared-off cooling fins
Dual ball bearing-supported crankshaft
Vertical fins heat sink head for optimum air cooling
Lightened hypereutectic machined Al-Si ringed piston
Rear reinforced resin cage ball bearing support
State-of the-art CNC machined components
2 Needle valves carburetor