14-07-2022, 06:57 PM
Hi Steve
I note your puzzlement at the lack of response so here are my comments for what they are worth (I’m no expert by the way).
On a 1 5/16 two bearing crank some whip is expected and white metal bearings can be scraped to relieve the edges and allow the whip not to be constrained. Shell bearings tend to be a constant diameter, slightly harder and would provide a hard edge to any whipping which may expedite failure of the bearing or crank!!
White metal on an Austin rod is relatively thin, replacing it with a shell bearing would entail boring out the aperture and weakening the rod.
I have a 1 1/2” crank in my special with Nippy rods and white metal bearings. If (I hope not soon) they wear out I will probably change to Hadley rods with Renault 4 bearings. There is much much less whip with a 1 1/2” crank. If you are determined to use shell bearings a 1 1/2” crank is probably the way to go. It does fit in a standard crankcase with some fettling!
I’ll leave it to the experts to comment if my views are right or wrong!
Cheers
Howard
I note your puzzlement at the lack of response so here are my comments for what they are worth (I’m no expert by the way).
On a 1 5/16 two bearing crank some whip is expected and white metal bearings can be scraped to relieve the edges and allow the whip not to be constrained. Shell bearings tend to be a constant diameter, slightly harder and would provide a hard edge to any whipping which may expedite failure of the bearing or crank!!
White metal on an Austin rod is relatively thin, replacing it with a shell bearing would entail boring out the aperture and weakening the rod.
I have a 1 1/2” crank in my special with Nippy rods and white metal bearings. If (I hope not soon) they wear out I will probably change to Hadley rods with Renault 4 bearings. There is much much less whip with a 1 1/2” crank. If you are determined to use shell bearings a 1 1/2” crank is probably the way to go. It does fit in a standard crankcase with some fettling!
I’ll leave it to the experts to comment if my views are right or wrong!
Cheers
Howard