[AndyB]

I have to inform you Andy that you are now the expert!!!

Only for a week or so Vic,  by then I'll have forgotten how I did it!

[VicYouel]

I have to inform you Andy that you are now the expert!!! 

[AndyB]

OK

I have now re-assembled the crank cases as follows - MC22 ball bearing and RMC22L single lipped roller bearing on drive side, and RMC22L roller bearing on timing side.

I removed the 0.8mm shim which I had placed between the flywheel and roller bearing inner on the drive side, and replaced it with one 0.5mm and two x 0.1mm  22mm x 32mm shims between the roller bearing and the ball bearing. This gives a barely perceptible end float, but the crank is nice and free and rotates smoothly. 

Both roller bearings need to have the lip on the outer race to the outboard side, otherwise the crank will be impossible to assemble!

I re-used the RMC22L with a slightly distorted roller cage, having ensured that when assembled, everything was free and easy to rotate, without being so loose that the rollers would interfere with the outer race when sliding the crank into place.

Thanks for all your help - be prepared for more questions in due course!

Andy B

[phutton]

I have used lipped bearings (RM22L) in my 26 M5. Only thing is I'm not sure which way round they should go! I put them in lip outboard of the flywheel on the basis that any expansion of the crankcase as it heats up will not move the bearing on the shaft. It also stops the roller part on the drive-side interfering with the adjacent ball bearing.

I may well be wrong, so can anyone give a definitive answer?

[VicYouel]

The more I study this appendix the more I get confused; I regret I do not know what to recommend anymore than what is stated. I note that shimming is also discussed. Hopefully somebody else will join the conversation.

Sorry

Vic

[AndyB]

Thanks Vic,

I hadn't appreciated the amount of detail available from RCC's book!

Just had a look at Table 4 in Appendix 3, page 188.

My parts book shows Sunbeam factory No.3958 for the two roller bearings, cross referenced in the table as either plain or single lipped outer.

Am I reading that correctly?

Andy B

[VicYouel]

Andy......why be embarrassed; that's what this forum is for to share information and experiences so we preserve our heritage. The data on this forum will be preserved.

I wish more people would contribute instead of being concerned about being wrong. I too am just an amateur.

Cordon Champ's book details all the bearings in an Appendix conveniently with proper part numbers. This was extracted from an old VMCC article by FM...... wonder who that was.

Vic

[AndyB]

Now I am trying to remember whether it should be a single lipped roller RMC22L!

Good luck

Vic

Hi Vic,

You are correct on this - it looks like I've ordered the wrong one - have asked them if they can supply RMC22L (they only ship at weekends so hopefully will be able to sort it out with them).

Is there an icon for kicking oneself?   

Thanks

Andy B

[VicYouel]

Heathcote goes on to state:

If the shafts are of the rivetted type the washers can be put on the shafts before the bearing. The other patterns in which the shafts are of the tapered fit type there will be a radius at the base of the shaft. In the latter case the washers must be put between the double bearings on the drive side. I would think you have the latter type of bottom end.

I know of one member who had his shims chewed up!

It sounds as though you have made it too tight.... it must be nice and free. As for keeping the bearings in line...... they need to a tight sliding fit on the shafts but will normally need to be put in the deep freeze before dropping them into the crankcase.

Now I am trying to remember whether it should be a single lipped roller RMC22L!

Good luck

Vic

Vic

[phutton]

If you shim between the bearing and the flywhell, there can be relative motion between the F/W and the shim - not a good idea! Shims should be placed in the crankshaft bearing housing, outboard of the bearings.

[AndyB]

I had a test on my bottom end for my 1933 model 9 done by Alpha. Will be identical to your one. It has just detectable end float.
Pitman's book by Heathcote states end float of 1 to 4 thou with lowest for a racing engine. You need to shim it between the two out drive shaft bearings.  Also make certain piston is central to crankcase halves. You have a little tolerance with gudgeon pin end float.
hope this helps
Vic

Thanks Vic,
That's interesting - I have separately been advised to shim between the flywheel and DS roller bearing.

In the process of removal of the inner race, have damaged the roller cage of the new bearing. 

Having installed a 0.8mm (31.5 thou by my calculator) shim and refitted bearing inner, now find nil end float and a shaft which no longer rotates as freely as it previously did. 

I've now ordered a new RMC22 bearing from here: http://www.veterantriumph.co.uk/common-spares-31-c.asp (less expensive than VBC), and a selection of shims from here: https://www.thebearingcompany.co.uk

It would certainly be much easier to shim between the two bearings - I'm just concerned about keeping the inner and outer races of the roller bearing in alignment.

Your thoughts on this would be appreciated.

Andy B

[singleminded]

I had thought the shock absorber pulls the crank towards the drive side like a pre war Triumph but this is not the case.

I thought the same when I built my 9A,then using my best anglo saxon said 'silly boy'....John

[VicYouel]

Andy,

I had a test on my bottom end for my 1933 model 9 done by Alpha. Will be identical to your one. It has just detectable end float.

Pitman's book by Heathcote states end float of 1 to 4 thou with lowest for a racing engine. You need to shim it between the two out drive shaft bearings.  Also make certain piston is central to crankcase halves. You have a little tolerance with gudgeon pin end float.

I had thought the shock absorber pulls the crank towards the drive side like a pre war Triumph but this is not the case.

hope this helps

Vic

[AndyB]

Hi all,

Rebuilt crank with new bearings from VBC - just test-assembled it and found 40thou end-float. Having acquired it in boxes, not sure what shims might have been in there, nor what end-float to aim for?
Would be grateful for any help.
Thanks
Andy B