Hi Ed,
My quick & dirty answer is that the 6 pinion
planet set is equivalent to a spur gear drive with a gear width totaling the
width of all 6 planets. That would be:
6 * .785" = 4.71" Thats a mighty
big & heavy spur gear!
That's bigger than the one in a P-51 R.R. Merlin
engine I think. Not an apples to apples comparison due to the difference
in bending strength of the tooth root but the biggie factor in power
handling capability is indeed the gear contact patch.
Tracy
The Merlin made about 2200 hp
with a spur gear 2 in wide. So that is roughly 1100 hp/in of linear
contact.
The Ford planetary would be 300/4.71
or 63.69 hp/in of contact.
Not exactly an apples to apples
comparison, but it gives you an idea of how lightly loaded the Ford planetary
is.
Monty