Nigel, I believe prop RPM factors in too. You may not be able to have
optimum 2-blade prop diam on the trike either, such as on the
slower-turning 914. High revvers maybe. I invite correction in
suggesting 3 can at times be better, as the 914 requires wider blades
to best absorb the power (implying benefit from more blade area, which
is what 3 do), and slow-turning turboprops and IO-720's often swing
sexy four-bladers.
A heavier auto engine will flex the nose gear leg more, reducing
clearance, but modification to the leg's stop appears do-able. The 6"
ground clearance on my other plane is a hair above that needed to
dethatch EAA's turf, taxiing around the grounds at Oshkosh. Go for
more, or stay on the hard stuff.
Regards,
Fred F., A063 (trike)
Nigel Charles wrote:
>
> The loss of efficiency for the 3 bladed prop doesn't seem to be as much as
> the theory would predict. The main reason for the 3 bladed version is to
> improve ground clearance - very relevant for the mono wheel. The necessary
> increase in diameter for a 2 bladed prop would increase the risk of prop
> strike. It may be practical to look at 2 bladed props with the tri-gear.
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