[stringfellow]

I have a IO-540-C4B5 narrow deck core engine. The crankshaft showed a crack during magnaflux inspection and thus is a reject.

The company I bought the engine from guaranteed the bottom end for serviceability, so they have presented me with a candidate crank. It is from a O-540-F1B5, which I understand is used in the R44 helicopter.

I understand it has a heavier duty prop flange? Is that a pro or con for aircraft usage?

Also, the Meyette page says it makes 260hp at 2800 rpm. Does that mean it's a different design crank? Could it be stroked differently?

Thanks.

Edit: A little more research has shown, at least anecdotally, that all 540 crankshafts use the same stroke. Still looking for any other known differences if they are crankshaft-specific.

Edit 2: Called Bob at Aircraft Specialties. He confirmed the crank is the same as fixed wing, but with different counterweights.