R975 Radial engines

[Bob Phillips]

Perry thanks very much for the impeller info! Looks a whole lot like the -46 impeller, does anyone know the significance of the holes through to the back?
As I mentioned earlier in this post tghere were weak points in the 975 engines, the impeller shaft/ bearings were certainly one. A second was the master rod/ crank bearing which often failed due to abuse or possible oil starvation. Any other known issues?
I also need to thank Perry for the opportunity to photograph his C4 cylinders next to a -46 cylinder. Please note -46 cylinder does not have an exhaust elbow attached.
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