Fitting Superblend bearings

Not much difference really Michael. Fit the superblend outers into the cases both sides. You will need to set the end float as you do not have the ball race bearing tolocate the assembly in position. It will be easier to do a "dry run" first and it is much easier to do this without the con-rods fitted as you will have is the the crankshaft and two case halves. The shims should go between the crankcase webs and the bearings inner races.NOC info says; 10-20 thou:

This is Norton shim (Part No. NMT2196A, later changed to 067569).

I like to fit the bearings so thebearing code is on thesame side for both inner and outer which will mean the brass rivetts face outwards.

You should shim with the aim to get theconrods central in relation to the barrel mouths and hence the crankshaft central to the crankcases.

Hopefully the inner bearings will be a fairly loose fit on the shafts as you will need to remove them after measuring to calculate the shims required.

If they are too loose it would be wise to use Loctite Bearing Fit to secure them after all shim sizes are known.

I note the official method is to fit the the crank into the timing side first, but it can be done the other way as you describe especially that you have superblend type bearings that allow easy slide in fitting off the main shafts to the bearings both sides. Many manuals forget this point.

Irecommend Welseal compound especially if you leave it around 1/2 hour or longer to firm up. It can be painted on whith a small artists brush, but I have never found any solvent to remove the stuff from the bristles, so use a very cheap one.

Les

Just to make it clear, Michael, you will NOT require any Loctite on the timing side bearingINNER race as this is clamped up by the oil pump worm/nut. Depending on the other clearances of the interference fits on thedrive side bearing races, it could be of some advantage to use it.

Les

Previously wrote:

The last time I rebuilt a 650SS engine it was with Roller and Ball Main Bearings. I remember the procedure as:

Roller Outer into Case. Rollers and Inner onto Crankshaft. Complete Ball into Case. Drop Crankshaft with Rollers into Case. Drop Case with Ball (after inserting Camshaft) onto Crankshaft. Bolt up.

For the first time I am going to try these "newfangled" Superblends so would like a procedure for the order to assemble these into Case/Shaft.

We never used to worry about Torque settings either (Mainly because even if they had given any we could not afford a Torque spanner). Suggestions for Flywheel/Conrod bolts would be appreciated.

Cheers.

Mick Pond. hello mike I fitted Superblend in my 500cc 1954, 88 And what job too get the end float right

Your Best Bet Is get the same brand that was fitted when it was New witch would be R&M .MJ30 timing side,and drive side R&M .3MRAJ30M these are For the 650cc Machines,And will cost around 90 pounds or more Try Vintage Bearings ? but there no messing with the end float ? hope this helps ?

Hi Mike, although you might be looking forward to it, as Anna quite rightly says, checking end float can be a nightmare job. This is simply because the drive side bearing can or should be a very tight fit for any bearing. You may well find that sliding on a bearing (inner bearing race, if superblend) means you cannot get it off unless a special extractor tool is used.

In my Model 7 Dommi, I have chosen the max load ball race which I got from Vintage bearings (Thanks Anna) it will cost around the same price as Superblend) but has the advantage that it securly locates the crankshaft as the original design intended The bearing is top quality FAG RHP M306. If you have notalready bought the two superblends.

I have read that some people think this is a non working set up mix as the superblends allow for crankflex but a ball bearing does not. This is nonsense as a ball bearing is probably even more tolerant than the superblend as far as self alignment goes.

The timing side has far less load, stress and strain than the drive side which is why most bike engines have a smaller bearing here and sometimes just a bronze bush!

However, you will in theory, need to set the end float, but you should be able to use the existing shim if you had one behind the drive side bearing. But ultimately as long as the bearing is not being pushed by any longitudinal thrust and the bearing inner is well positioned as far as the track is concerned, which it should be if the crank and cases are original, all will be fine and held in place by the ball bearing on the timing side. You also have to remember that the case will expand with heat so the end float will increase to about an extra 4 thou, which is why I think 20 thou to start with as per NOC seems way too much, But hey, they should, repeat should, know best!

So with a hot engine if you have a 24 thou of end play, it could, on occations, hammer the oil pump worm, which is very bad news. I would not set up an engine with a possible 24 thou end float.

Only my opinion though.

Good luck

Les

Just to qualify the word hammer, Ididn't mean destroy, I meant knock, as in moving around as far as the worm and pump gear teeth intermesh. Another point about the worm and oil pump is thatthe pump at max oil pressure (especially6 start worms and high capacity pumps) produces quite a pull or thrust load to the right on the crankshaft. A ball bearing can accomodate side loads very well, but a roller bearing is not designed at all to take any side thrust as it just pulls the edges of the rollers against the side edge of the bearing track. This contact is a rubbing action and not a rolling action. In the Norton engine this will mean the timing side bearing andalthough the bearing is quite large, it is just bad engineering to rely on a roller bearing to run with a side thrust, so another plus for a ball bearing on the timing side as per original design.

Les

It is easy to set end float is if you have a pair of spare old inner races. Grind out the inner diameter of the race to give a clearance fit on the crankshaft, then you can get them off and on with ease until you arrive at the correct shimming.

To Robin Goddard. Just to add that setting the end float with a ball bearing timing side, will require a spare bearing with agound a down outer circumference,OR you could relax the fit on the shaft a touch so the timing side main shaft can slide off a little easier. The bearing has the advantage of being clamped tight on assembly to rectify the looser fit. The fit can be loosened by removing main shaft metal (easy) or the bearings inner circumference (not so easy)

Even though most shimming will be done only behind the drive side bearing, the shaft still requires a freedom of movement for the end float measurement to be actually taken.

Les

Previously wrote:

Hi Mike, although you might be looking forward to it, as Anna quite rightly says, checking end float can be a nightmare job. This is simply because the drive side bearing can or should be a very tight fit for any bearing. You may well find that sliding on a bearing (inner bearing race, if superblend) means you cannot get it off unless a special extractor tool is used.

In my Model 7 Dommi, I have chosen the max load ball race which I got from Vintage bearings (Thanks Anna) it will cost around the same price as Superblend) but has the advantage that it securly locates the crankshaft as the original design intended The bearing is top quality FAG RHP M306. If you have notalready bought the two superblends.

I have read that some people think this is a non working set up mix as the superblends allow for crankflex but a ball bearing does not. This is nonsense as a ball bearing is probably even more tolerant than the superblend as far as self alignment goes.

The timing side has far less load, stress and strain than the drive side which is why most bike engines have a smaller bearing here and sometimes just a bronze bush!

However, you will in theory, need to set the end float, but you should be able to use the existing shim if you had one behind the drive side bearing. But ultimately as long as the bearing is not being pushed by any longitudinal thrust and the bearing inner is well positioned as far as the track is concerned, which it should be if the crank and cases are original, all will be fine and held in place by the ball bearing on the timing side. You also have to remember that the case will expand with heat so the end float will increase to about an extra 4 thou, which is why I think 20 thou to start with as per NOC seems way too much, But hey, they should, repeat should, know best!

So with a hot engine if you have a 24 thou of end play, it could, on occations, hammer the oil pump worm, which is very bad news. I would not set up an engine with a possible 24 thou end float.

Only my opinion though.

Good luck

Les hello Les as I have said the original speck bearings R&M Are better then the FAG bearings thats made in the EU , R&M are British Made And Are Stronger than FAG bearings ? The Number I have put On The Thred Are The Original numbers for R&M Bearings and are more expensive than FAG bearings And Superblend bearings ? And There is a Racing Bearing Made By R&M for the 650 SS ? if anyone wants them ?? Yours Anna J

Previously wrote:

Just to qualify the word hammer, Ididn't mean destroy, I meant knock, as in moving around as far as the worm and pump gear teeth intermesh. Another point about the worm and oil pump is thatthe pump at max oil pressure (especially6 start worms and high capacity pumps) produces quite a pull or thrust load to the right on the crankshaft. A ball bearing can accomodate side loads very well, but a roller bearing is not designed at all to take any side thrust as it just pulls the edges of the rollers against the side edge of the bearing track. This contact is a rubbing action and not a rolling action. In the Norton engine this will mean the timing side bearing andalthough the bearing is quite large, it is just bad engineering to rely on a roller bearing to run with a side thrust, so another plus for a ball bearing on the timing side as per original design.

Les

Les,

Would you advise the heavy duty 10 ball bearing as being suitable for usein the 750 and 850 engines also?

Don Richards

Good question Donald. As the official recommendation is 2 superblends, I would not want to overide that. I have read that it has been done and is sometimes prefered because of the positive crankshaft longitudinal or lateral locating that the ball bearing provides. With some web surfing, you might find some actual cases of this set up being chosen. The 750 and 850 capacity does push the limits for the main bearings on these engines, so one couldsay that 2 superblends gives the maximum loadcapabilty for that size.

However, as I said above, the timing side bearing does have a slightly easier life, and in practice it is pointless having a set of bearings that one outlasts the other, as you will allways replace both at the same time during a rebuild. Furthermore, the max load ball race will locate the crankshaft positively and haveless friction which are two advantages. Theend loading of the oil pump thrust is also accomodated correctly by the by the ball race too.

As most Commandos run 2 superblends, without trouble I would have to say stick with the crowd, but whether the max load ball racewith one superblend is a better, more refined engineering choice, only a high mileage hard used engine strip down with that set up would give the evidence and proof.

I'm sure it has been done, butI haven't, as when I did own a Commando, everyone just put in two superblends without a second thought. If I had one now, I'm would be chasing up as much infoas I could find to see how the mixed set performs in comparison, It certainly appeals to me.

Sorry I cannot be more specific, but I hope other members can help you more with hands on experiences.

Regards.

Les.

Why use Superblend bearings, which were part of solving the 1972 Combat engine problems and have since been used in all Commando engines, Road and Race, if a more obscure solution can be found in 1960s folklore? It is far more interesting to speculate on what MIGHT work than to use something that works for everybody else, don't you think?