ORIGINAL: Sport_Pilot
On the big radial engines -this was a problem
That can be minimized with a good cowl design. A good radial cowl will allow the prop blast to go through the engine and out the back so that the prop will still provide good thrust, though slightly less than the outer blade.
The prop does not blast thu the cowl -
not how it works
but proper cowl and spinner does make a BIG difference.