Engine Installation

The first engine going on the P1 is a Rotax 503 (Installation Manual, 4MB), with dual electronic ignition and a single carburetor. A second carb will probably be added later (52hp vs. 46hp), in addition to a high-altitude mixture control kit. The propeller is a two-blade GSC 68" ground-adjustable prop.

The engine mount is made from a 1/4" plate of 6061-T6 aluminum, suspended from 1/4" angle brackets via elastomeric bushings.
The exhaust system is suspended from the boom via two strut supports, each with an elastomeric bushing similar to the one on the engine mount. The struts were water-jet cut from 6061-T6 plate, cleaned up, then anodized. The first version was 3/8" thick, and was replaced with a reduced-thickness version with smaller struts that cut the weight by about 50%.

The Rotax 503 is an oil-injected engine requiring an external tank gravity-feeding the oil injection pump (at the rear of the engine). The tank is a Rotax part, held to the boom by a carbon-fiber bracket and worm-drive clamp.

The carburetor is fed fuel through a pulse-driven pump. The center blue tube supplies an air pressure pump as the engine turns, compressing a diaphragm that pushes fuel through the pump. A blue regulator-rectifier converts the variable-frequecy, variable-voltage AC output of the engine generator into regulated 12VDC that can be used by the electrical instruments on the airplane.

The Engine is mounted to the baseplate with 4 AN6 bolts in tension, and to the boom with 8 bolts (4x AN3C and 4x AN4C) in single shear.