CJ1 engine bearings

Can you tell us what the markings are on the existing bearings?

Mike

Oops!  My error.  I missed that you do not have the old bearings.

Sorry

Mike

If you are asking about main bearings the CJ1 bearings are the same as those fitted to the CS1, M30 and M40.

The timing side ball bearing 1"x2.5"x3/4" is a MJ1.

Drive side ball bearing 1.125"x2.5"x5/8" is a LJ1 1/8.

Drive side roller bearing 1.125"x2.5"x5/8" should be a single lipped bearing which I think is a MRJ1 1/8. The non-lipped version is a LRJ1 1/8.

A C3 fit is the preferred option for these bearings.

You could try RacingNorton.co.uk for the bearings as they list them or allternative brands.

Regards

Nick 

Hi Philip.

Sounds like a modification, perhaps after damage to the original bearing housings. 2 7/16" does not match any standard imperial bearing size. The dimension is close to 62mm but the shafts on the crank are not a metric size as standard. Maybe it is an unfinished modification and the steel housings require boring out back to the standard size.

Are your crankshaft bearing surfaces the standard size? If so then I think returning the bearing housing back to the original size would be the best option so you can use standard bearings.

You will need to find a competent machine shop to do the work.

Hope this is of some help. Nick

Not being rude but in the absence of a picture and not knowing your level of knowledge, am wondering if it's the old outer race that has been left in the casing?

Hi all,

   For what it's worth, a 62mm bearing was fitted to all magnesium garden-gate racing engines on the timing side crankcase only, but this bearing was completely different to the type fitted to the road specification engines. If a steel liner has been fitted to the original 2.5 inch (63.5mm) hole this would only be 0.75mm or 30 thou. thick!! If the cases have been opened out and a proper size liner fitted it would be best to bore it to the original 2.5 inch.