Dominator timing side main

The 88's std bearings are well up to the job. If the end float is ok I would leave alone. If stripped I would fit a ball bearing which should not be a very tight fit on the shaft. If the case bearing housing is unworn then a c3 will be best.If the bearing is loose in the case then a bearing with less internal clearance will work with locktite bearing fit.

C3 is a later recommendation and allowed a greater interference fit to be used on the cases so the bearings do not spin in the cases, unless your CN bearings are causing drag on the crank leave them alone. For some reason loctite on a steel bearing outer in an alloy housing does not work for long, my educated guess is the loctite cannot cope with the difference in expansion rates between the metals and gives up after several heating and cooling cycles. A permanent fix is to copper plate the OD of the bearing or sleeve the housing.

Vintage Bearing Company have currently 2 of the 11 ball high capacity bearings in stock. Leave the drive side bearing as it is and swap the timing side for either the standard 6306 ball bearing or the superior 11 ball version. I prefer this set up rather than the use 2xNJ306E's as it keeps to the original design...The price is a TOTAL of £75 (includes VAT and postagel) which is about 9 times the price of the standard type..... Perhaps only fit this expensive bearing if you have everything else downstairs in perfect renewed order...Eg: reground big-ends & brand new camshaft as you should have an engine that should last your lifetime. In std form for a relatively unstressed 500cc engine the std. bearing is sufficient but like most of us we sometimes are not happy unless we take things to their limit quality wise and we can rest happily then.

In addition to what John (above) has said about the bearing outers rotating and (they often do...certainly on the drive side) One fix was to notch out the side of the outer race and fit a screw alongside to prevent the rotation. Also note there are different grades of Loctite...the strongest and hardest one used to be called "Retainer"...not "Bearing Fit" as is often used....check their modern equivalent number...can't remember it of hand....you might wish to use it if your bearing fits too easily.

One other way I though of is to grind a groove across the outer face of the bearing. Then fit the bearing and then with a small HSS drill bit drill along side the groove. As the alloy is softer the drill will drill a neat groove alongside this bearing groove. You can then tap in a small steel peg the same length as the bearing width(or a touch shorter) for a nice tight fit between the two. The alloy case is then peened over to retain the peg.

Les

I've checked the Loctite catalog and the best bearing fit product (Equivalent to the old "Retainer" product) is Loctite 620...High Strength and High temp (230 C upper temp)....note Loctite suggests using a primer either 7649 - 7471.

Les

Peace of mind is valuable. If as you say you have found other dubious bodges then thats the way to go.Sounds like the crank is shimmed so a few thou off a shim may be all thats needed . Old rods can go slightly oval and bind if you regrind and fit new shells ,I think this can be avoided if used but servicable parts are refitted .Try not to swop or reverse the rods.Journal radius is worth checking if has been reground before.

The Correct Bearing are Ransome & Marles MJ30.Ball timing side and MJRA30-3 drive side these are still availableif you do yourresearch and there not cheap either Norton At Bracebridge street did only fitted the best components availableat the time. but having saidall this you can fit FAG NJ306E with made in Germanystamp marked on them these are a direct copy of Ransome & Marles Bearings and well up to the job yours ANNA J

Hello Now Some FAG bearing are copies and made cheap so look for the right stamp markings I have seen FAG super blend with metal cage, these are the copies the real ones have a Bass Cage for the rolls so owners beware of what you're buying there is some fake Norton parts out there , yours Anna J

Regarding Anna's post, SKF web site did have a page with pointers on recognising counterfeit bearings. Apparently there's a thriving black market in clean bearing cardboard boxes to be use to present counterfeit bearings. Oddy I seem to remember the counterfeits actually had clearer lettering etched on the sides.