Crankshaft Failure - a remedy from 1964?

[Zetomagneto]

Like Bob, I'm somewhat sceptical about the influence clutch loading has on crank failure. I'd wonder too about the effect on timing gears. I'm trying hard to visualise what happens to cam and ignition timing as the crank whips.  Interesting- it might even be beneficial.
Ever since God was a lad people have been investigating new bearing arrangements for Austin sevens. The one that interested me, years ago was self aligning bearings. Crank whip exerts a far greater force on the engine than clutch loading. Try bending a crank 25 thou and you will see what I mean. I think allowing the crank to bend freely is far more important than absorbing the clutch load.

My only interest in using a ball rear main is to save repairing a broken lip on one of my crankcases.
You would need to make up a spacer to go between the flywheel and inner track.

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I too have been interested in this since Charles P raised it as a side issue in a post (Odd Noise) about a year ago. I've sourced the ball race he mentioned as well as a pair of 1 1/8" roller races for the front bearing. My interest is to try to lengthen the life expectancy of that much maligned 3 bearing crank, which must suffer unnecessarily from bending loads when the clutch pedal is depressed. Bearing in mind that the centre webs are only 0.3" thick, is it surprising that so many failures occur in that area?
Having suffered the total destruction (at 20 mph) of the bottom end of a 2 bearing engine I'm keen to try a 2 bearing conversion as well.
 The roller races are available from Bearing Services Norwich Ltd who showed interest when I explained what I was planning to do.

MRJ1.1/8C3

Cylindrical Roller Bearing, rollers attached to inner ring full floating outer ring (1.1/8x2.13/16x13/16) (BSA Goldstar crankshaft drive side 1950-1953, OEM 65-1388



Manufactured for us by NKE Bearings Austria


Hope this is helpful and causes others to other interested parties!
Cheers
Bob

These are the bearings used in the earlier engines, nothing special about them, readily available from our cherished suppliers, check prices before buying, Jamie does RHP.I wouldn’t use cheap bearings.