I'm, slowly, re-assembling a two-bearing engine. I didn't remove the camshaft, but have been left with the job of re-fitting it. I've got eight rollers, but it looks like there there's space for nine.

Can anyone confirm how many should be fitted please?

Location: Bedford

Shuttle - You haven't mentioned what type your motor is, beside being 2 brg. If it's a Standard engine, you need 9 rollers 5/16" by 5/16". If Nippy or Speedy, you need 8 rollers 3/8" by 3/8". Hope this helps, Cheers, Bill in Oz

Location: Down Under

Many thanks for your reply.

I assume it's a standard engine, but now I'll be able to go and measure them, but it looks like I've one missing, soddit!

Location: Bedford

Shuttle - I forgot before to include an Ulster camshaft, but I think by now you would have discovered it was "different" if yours was one. For a start the front camshaft bushing for either a 9E2 or 9E48 (thicker) shaft is 1 5/8" OD, as against a standard bushing (coil or mag) of 1 1/2" OD. I'd be surprised if someone on the Forum doesn't offer to post you a roller, as yours is probably a standard one. Again, Good Luck. Bill in Oz

Location: Down Under

Location: Shropshire

Whether it is an incomplete bicycle bearing, or Seven a/c bearing etc, for anyone contemplating adding or assembling odd balls or rollers it is worth noting that new balls of a batch are within a tolerances range less than .0001 inch. For a basic bearing such as camshaft probably not too critical but prudent to check no difference more than say .0002. Used rollers may be .001 and more undersize.

Location: Auckland, NZ

Bob - where does the factory say that? Cheers, Bill in Oz

Location: Down Under

Hi Bill

I dont understand your question. Ball bearing books give tolerances, presumably batched very close for a purpose. It seems reasonable to assume a near new roller mixed in with well used ones maybe .001 or more different is not a condition ball race makers would consider conducive to long life.

Location: Auckland, NZ

I intend ordering a complete set of rollers, once I've measured and confirmed the size fitted and if the 'powers that be' approve the expenditure! I'm only working on it one day a week (It's in a museum and other work sometimes takes priority).

Just a thought, what would be better, running with one roller missing, or with the correct number and one 0.001 oversize of the rest? Not that I intend doing either.

Would one thou matter? Not sure.

If you measure the others do they vary by one or two thou anyway?

Boib - as usual you are correct in theory, but I've checked around and like me no-one I asked has ever had trouble with the measurement of centre bearing rollers, because (a) they are such a loose fit and because (b) they are so well lubricated with engine mist. They are not put together with fine tolerances as a complete assembled bearing would be. I will say however that it's possible to - very rarely - find wear in the ring itself, but if so one just turns it around and puts it back in. By the number of enquiries (and answers) on this Forum, you should be aware of how many have difficulty getting the rollers to stay on the shaft when installing because of the extremely loose fit. So the unlikely wear of one thou would not make a scrap of difference - and that comes from the experience (not theory) of several I've asked. And I'm sure that if there ever was a problem, the Austin Service Journals would have made everyone aware. Cheers, Bill in Oz

Location: Down Under

Hi Bill

You seem to be reading into the comment something which was not there. The cam rollers in an old engine may be .001 under but usually all the same so of little consequence.

Location: Auckland, NZ

They were standard 5/16" and I've ordered some new ones.

Now to sort out the bent con-rod! Not having an old gudgeon pin I could braze a flat plate to (Woodwward), I cut a length of 1/2" rod about 6" long and inserted it through each little end, then turned the engine until it was just resting on a couple of known flat steels. Swapped steels over, then inserted rod other way to compensate for any inaccuracies.

Putting those bearings in can be a right game if you dont know how!

Some people stick them to the camshaft with grease, which works, but you need a steady hand feeding the cam in through the bearing hole.

I use two of those little rubber bands about an inch long when at rest. Assemble on the bench. feed the rubber bands over the camshaft. Place each roller under the bands until all 9 are in place, then it is an easy matter to slip the camshaft into the engine, as the centre bearing slips in, the bands will just push off, leaving the bearings in place. Then just snip the bands off the cam. remember to line up the oil hole in the end bearing before sliding the cam home.

Stuart.