Hi everyone,
Yesterday I pulled down a 1275 engine that I had sitting under the bench.
One thing I came across was some wear on the end of the crankshaft. The taper feels okay, but there is definite wear where the primary rums. Hopefully it clear enough in the picture, but the scores are deep enough that a quick polish probably won’t fix. Is this an issue? If it’s ground down, are oversized bushes available for the primary gear?

Cheers,
James.

I replaced the outer flanged bush in a 1275 primary gear recently. It was undersized, I bored it out after fitting.
I think it was about 0.010" undersize before boring.
These are sintered bronze and pretty fragile.

At the other end, a floating silicon bronze bush is available but is standard size.
If the original 1275 bush is still available it would be undersize too.
1275 cranks can wear badly there. One solution is to grind the 1.625" journal down to 1.500" and fit a 998 primary gear. Use with 1275 thrust washer.
Some racers have done this mod.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I had to choose to machine a 1275 crank to suit a 998 primary gear some time ago, to date I have 12 years and about 25000 kilometers without an issue from this modification.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Thanks for the info guys. It looks like all is not lost.
James

Polish the burrs off and measure it with a micrometer if it's only a thou or 2 under 1.500", stop worrying.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.