I was starting the rebuild of the engine and found that both the new bearings for the drive side of the crank shaft are C3 & the roller on the timing side as well is C3. While the outer bearing is a standard bearing . When ordering that ball bearing race as a C3 I was told it is not available.
Is it possible that someone might have one for sale or a contact for a supplyer
Thanks
email (option): Michael@nammech.com.au
Hi Michael, The Imperial bearings (the two on the timing side) are getting impossible to find in the correct C3 fit..in fact RHP have stopped producing the lipped roller (MRJA7/8) for that side altogether.
I suppose it's just a case of insufficient demand.
C3 bearings have slightly more internal clearance to allow for the degree of 'fit' into the crankcase.
Dimensionally this is a matter of microns...not thous.
I have always used bearings of the correct fit but it is the case you can't fit what you can't buy!
In 30 or so years I have stripped numerous M and B Series engines that were running fine on non C3 fit bearings and have yet to see an engine of either type that has suffered a main bearing failure.
It seems the implications of fitting a non C3 bearing are not catastrophic bearing failure but perhaps a slightly higher wear rate in service.
The effect on overall bearing life is impossible to quantify as numerous other factors, such as frequency of oil changes, running and load conditions also have an effect.
If we are talking of a reduction in bearing life from say 90,000 miles to 70,000 miles that couldbe deemed an academic difference for all but the 'high mileage' riders of today.
As I mentioned, I have never seen a failed bearing..but obviously I have seen worn ones!
Currently, to answer your original query, I don't have a supplier for this bearing in the correct fit...it may be the case that you have to keep hunting in the hope of finding 'NOS'. First stop for that would be Russell Motors I would think..unless another forum member knows different!!...Ian
email (option): julie@wright52.plus.com