E: Engine Interesting big end...

G

GBewley

Well Known and Active Forum User
VOC Member
Good day!

Attached you will find a photograph of a big end a customer recently supplied for building the crank for his post-war twin. He tells me that it came out of an Alpha Bearings box, but I have never seen a similar big end before. This is not a great photograph, so a few details: The slots in the cages take 1/4 diameter by 5/16ths long rollers which are fitted into the reduced diameter on the pin and then held by the cages. There is a spacer for the rods which fits over the largest diameter on the pin. It is all very well made, but I've never seen one of this design.

Just wondering if any of the other members here have seen this design and recall anything about their performance.

Thanks for any and all comments!

Glenn


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bmetcalf

bmetcalf

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VOC Member
I had heard there was a superb photographer in your area, maybe he could give it a go? :)

Are there adequate fillets in the various corners? They look pretty sharp in the pic.
 
mercurycrest

mercurycrest

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VOC Member
It reminds me of a CF Smith big end. I had a Comet one very similar. It was the big end you used until you could afford a proper Alpha.;)
 
Len Matthews

Len Matthews

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VOC Member
mercurycrest said:
It reminds me of a CF Smith big end. I had a Comet one very similar. It was the big end you used until you could afford a proper Alpha.;)
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I came across a big end from an ex-Argentine Rapide that had the standard crowded roller arrangement on one side.The other had the crankpin diameter ground down to accept much larger rollers.That seems to be a lot of work to keep the bike on the road but presumably a proper replacement was not available in Argentina.
 
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