Question:

Handpropping a rotary engine ... Possible?  Easy/Difficult?
Robin Berglund


Difficult due to the gear box. One rotation of the prop is
2.88 revs on the engine. A lot depends on the EFI tuning
and the position of the fuel injector relative to the rotor
housing.

Also it is a function of prop inertia. A low inertia
wood prop would not help.

Paul Lamar


While the effort (perceived torque) to turn the engine with the prop
will be relatively high, swinging the prop a relatively short distance
will cause a comparatively large (and fast) rotation of the engine -
aiding in starting.  The rotary's relatively low compression ratio and
small displacement may make it possible.  In a way, isn't propping a
geared engine much like propping an engine with a large number of
cylinders?

Has anyone tried it?  It should be approached with great care as
propping any engine is potentially very hazardous.


Matt-