Subaru powered scorpion kit helicopter modification
|The Rotorway Scorpion complete with Subaru engine installation and rotorblades installed.|
Enclosed are some of the photos of my Rotorway Scorpion helicopter. I totally rebuilt this ship from the ground uparound the Subaru EA81. Several modifications have been made to the airframe. The water pump was eliminated from the frame with the fan counter drive which eliminated three (3) belts. The fan is now direct drive.
I designed the new flywheel, clutch idler and starter plates. Internal modifications were also made to the crank case for proper oiling with the engine in a vertical position. The intake is a stock unit modified for a side draft carburetor.
The radiator is an aluminium unit out of a Renault. The engine's oil system works perfectly and as of now the engine has accumulated ten (10) hours - it is smooth and quiet.
The engine turns the blades counter-clockwise which required some rotorhead changes including a sprag clutch and tail rotor drive reversal. The clutch system was designed to allow the engine to start and run without any blade movement. This approach eliminates starter torque impact.
Right now i am running Hughes 269 blades which have proven to be unstable due to the flexing and (built-in) blade twist. I have decided to remove the Hughes 269 blades and install stock Rotorway blades. The ship has worked out very well and can not be compared to the Evinrude configuration.
The ship has hovered but i have experienced instability problems, however i feel i will overcome these problems as Igor Sikorski did.
|Close up of the right side of the engine. Note the coolant filler tube and cap next to the fan cooled radiator. Ron also had to modify the engine oil passages and sump to allow the Subaru powerplant to operate properly in a vertical position|