The Terry Burtz 5 main bearing engine blocks are back on track.

[Terry Burtz, Calif]

40 Delux

Pietenpol's were all homebuilt and likely used a 2 blade homemade propeller. What is scary is that one blade likely grabbed more air than the other blade which resulted in high bending loads on the 1.625-inch diameter main bearing.

Early Funk airplanes used a dry-sump inverted Model B Ford engine and these airplanes were factory-built and benefited from the larger 2-inch main bearing. The propellers on Funks likely had less miss-match between the 2 blades.

[40 Deluxe]

Originally Posted by Terry Burtz, Calif

40 Delux

Pietenpol's were all homebuilt and likely used a 2 blade homemade propeller. What is scary is that one blade likely grabbed more air than the other blade which resulted in high bending loads on the 1.625-inch diameter main bearing.

Early Funk airplanes used a dry-sump inverted Model B Ford engine and these airplanes were factory-built and benefited from the larger 2-inch main bearing. The propellers on Funks likely had less miss-match between the 2 blades.

Thanks, Terry. The question remains, however: How long did the original thrust surface last, what with having to pull the airplane through the sky?

[Bruce of MN]

Originally Posted by Terry Burtz, Calif

a dry-sump inverted Model B Ford engine

I can see where a designed inverted engine like for the Bf-109 would handle the oil in the crankcase, but what they did to convert the B engine would be very interesting.