Wildguzzi.com
General Category => General Discussion => Topic started by: Canuck750 on November 23, 2022, 09:59:42 PM
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I have a couple pressed up crankshafts for a 4 stroke Benelli single, Benelli used the same diameter of the crank pin and the I.D. for the connecting rod big end across a variety of displacements (egg motors 125 / 200 / 250cc).
(https://i.postimg.cc/3JjzkFWR/BAB4-B758-FE07-4-A64-A44-A-874197-E82-D03.jpg) (https://postimg.cc/Vd6KTMqQ)
These motors use needle bearings that are loose fit into an aluminum cage. There are 16 of these hardened rollers that one fits into the cage after slipping the cage over the pin then the con rod over the bearing.
I can't find any NOS Benelli rollers / cages but I did find a complete new needle bearing of the same dimensions (24mm I.D. / 30mm O.D. x 15mm wide) at 123 Bearing in the U.K.
(https://i.postimg.cc/CxFNkbRQ/B-10-K22-30-15-SKF-EN.jpg) (https://postimages.org/)
https://www.123bearing.com/bearings-K22-30-15-SKF
Is there any reason why this needle bearing would not be a suitable replacement for this high stress application?
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I see no reason why not. These are commonly used on 2-stroke cranks and con rods and are fitted to my Bridgestone 350 GTR wrist pins.
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I would think so too, but what I'd do is to search or enquire directly to SKF explaining the application to see if they have any comments
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I would think so too, but what I'd do is to search or enquire directly to SKF explaining the application to see if they have any comments
Good advice, thank you
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I would think so too, but what I'd do is to search or enquire directly to SKF explaining the application to see if they have any comments
:thumb:
It's also worth checking the old bearing for any numbers as most of them are universal so as long as they match you should be good to go
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Setup is similar to the BMW /2 crank.
The fellows who were doing the /2 cranks would often re-use the bearing cage as it was rare, and just replace the rollers.
Part of the reconditioning often involved dressing the rod big end with a precision hone
Final fitting was done by installing appropriate diameter rollers.
Seems rollers are available in .0001" increments of diameter.
Ideal fit is about 0.0002" radial play on the rod.
0.002" is still acceptable (HD Manual figure for their crank).
YMMV