This is the Cylinder Liner for the O.S. 91HZ
F3C Competition Helicopter Engine and the
O.S. 91HZ-PS 3D PD-08 Pump.
5-ports cut in Constructed of steel
One Cylinder liner
Outside Diameter: 31mm
Inside Diameter (bore): 27.65mm
Installation into the OS .91HZ-PS or the O.S. .91HZ F3C