MAX-91SZ-H RING was the champion engine of the FAI  World Championship in 2005 and 2007 consecutively. It performed perfectly from stable hovering to dynamic aerobatic maneuver. Based on this distinguished engine, MAX-91HZ has been improved greatly corresponding to users’ requests in the field of F3C. The slim heatsink head fits into fan shroud without having to cut it. So the fresh air reaches the heatsink head and the carburetor without any loss. The improved areas are the scavenging port, exhaust port, crankcase heatsink, and the new heatsink head. The combination of these modifications contributes to cool performance and stable power output. In addition, the engine noise is reduced by improving the overall balance of the engine for smoother higher engine performance. MAX-91HZ has succeeded in acquiring champion quality to win FAI F3C keeping its “easy to tune” and “consistent R.P.M.” nature achieved by the fine tunings through our unrelenting effort.
 

Crankcase Heatsink


The newly designed back plate fulfils a role of heatsink. It is efficiently cooled down by the fresh air through the air inlets of full-covered helicopter body shell.

Piston & Cylinder
 

 
 The piston is modified to attain a lighter body and better performance. The combustion gas presses on the piston ring from within through the five holes laid out on the piston top to minimize the blow-by gas.So the combustion energy is effectively transferred to the crankshaft..
 

Displacement：：14.95cc.(0.912cu.in)- Bore: ：27.7mm(1.091in). 　- Stroke：24.8mm(0.976in)
- Weight:618g(21.8oz)- Output 3.4ps/15,000r..pm.
- Practical RPM 2,000～16,000r.p.m.