Crankcase superblends revisited

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DogT

DogT

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I'm getting conflicting information on the Suberblends. Talked to Angie this morning and she said their Suberblends are NJ306E C3. Another article I have concerning them also mentions C3. I sent an email to Norvil to ask if his superblends were C3, and Les says the C3 is for the "Dommies, up to 1966," and would sell me a C3 bearing for a Dommie, not a Commando.

Then there is also the polymide and brass cages. Has there been any updated information on this? I did do a search, but most of the posts were a year or more old. In any case, the bearings seem to run around $76USD + s/h from the UK, around $125USD + s/h in the US, and at my local auto store, they crossed me to a Timkin MR1306EL for about $77USD no s/h, each, but didn't have any information on it.

Any ideas please. I'd like to get this bottom end back together. There was minimal junk in the sludge trap, the journals look real clean, and the big end shells have very little scoring, just a bit where the oil hole is.

Crankcase superblends revisited


Dave
69S
 
DogT said:
There was minimal junk in the sludge trap, the journals look real clean, and the big end shells have very little scoring, just a bit where the oil hole is.
Click to expand...

Was there an oil filter? I'd expect minimal stuff in the sludge trap for an oil-filted bike.
 
No, never fitted an oil filter. Bike has 13K miles on it. Maybe I changed the oil a lot.

What did you do for your superblends, Dave??

Dave
69S
 
I'd use US Timken bearings in a heatbeat, having used them in the past for just about everything. You can get that bearing much cheaper from a bearing supply house like this one: http://www.jbr17llc.com/timken-items.html They quote $41 and change.

HOWEVER, like everything else nowadays, Timken may not be what it used to be. If the bearing was chinese, I wouldn't use it but sadly that could occur with any brand today. :(
 
hi dogt,when you emailed norvil did you mention that you spoke to angie and what they was recomending,wonder what happened in 66 that later models would need a different bearing
 
Mike,
Thanks for that link I will check it out. But like you say I will stay away from the Chinese if I can. Can't even get sheet rock right!!

Chris,
Well, I talked to Angie first and she mentioned that they only use the C3 (correct according to her) bearing. I had sent Les at Norvil an email and he responded about the Dommie and the C3 after I talked to her. I haven't a clue what to do at this point. It actually may not matter, I am only going to ride this bike around here in the foothills of the Blue Ridge on 2 lane 45mph roads that you can't see over the hills. I'm not a high speed interstate or race driver. Not like I'm going to Alaska on this bike.

I'll play this out for a while.

Dave
69S
 
FWIW I use the C3 bearings in all my race motors....never had a problem!! Dommies never had superblends......Les Hemmoroids is having a laugh!!!
 
Chris,
I can't answer your question. I talked to Angie first, and she said the C3 is correct for the Commando. Then I sent an email to Norvil asking if their superblend is a C3 and Les responded that the C3 is for the Dommie, not the Commando. Now Seeley is laughing at Les, I am pretty confused at this point.

Dave
69S
 
So, we should be concerned with the clearance between the roller and the race to absorb the effect of press fit and thermal expansion? C3 is stated as being “greater than normal clearance”
With the price of the NU306E.M1 being the same as the NU306E.M1.C3, I guess a knowledgeable decision will need to be made based on this difference.
The voice of experience needs to speak. Can there be that much concern in regards to the needs of the Norton under non competitive stress?
I’m listening.
 
I have a mid year 72 combat, does any other combat riders know when Norton corrected the problem?
Has any one opened up an orig. 1972 and found factory superblends installed?
Not trying to hi jack DogT's post just figured we are on the topic of main berarings.
DogT I'd go with the C-3 clearance because your riding style in allot like mine.
Summer crusin. I'm using a C-3 clearance bearing in my gear box for the layshaft.
I think if we are not lapping the track 50 times counter clock wise we are fine w/ a well made
moderrn C-3 bearing.
Marshal
 
MarshalNorton said:
I have a mid year 72 combat, does any other combat riders know when Norton corrected the problem?
Has any one opened up an orig. 1972 and found factory superblends installed?
Not trying to hi jack DogT's post just figured we are on the topic of main berarings.
DogT I'd go with the C-3 clearance because your riding style in allot like mine.
Summer crusin. I'm using a C-3 clearance bearing in my gear box for the layshaft.
I think if we are not lapping the track 50 times counter clock wise we are fine w/ a well made
moderrn C-3 bearing.
Marshal
Click to expand...

I don't think it's a hijack quite yet. We're on topic. Let us know, DogT, and we'll back off.

I believed the cases were updated between 260000 and 280000. I have recently purchased a Late set of updated reinforced Combat cases "210xxx" with the rollers still in place. When they arrive I will see exactly what they used and pass the info on. Maybe by Friday.
As far as the cage goes, for half the price and nothing negative forthwith, seems like the Polyamide case would be a reasonable choice.
 
To get the correct fit at running temp and stop the bearing spinning in the alloy crankcase you need an interference fit on the main bearing, this crushes the main bearing when the engine is cold and can cause tight running and premature wear so it is normal for a C3 bearing to be fitted in an alloy case. This is common to all the BSA, Triumph and Norton engines I have worked on, have even found C4 in some BSA's so Les is taking out of his arse which is nothing new.

PS I have been using polymide cages in BSA's for tears with no ill effects.
 
I have also used the bearings supplied by Mick and Angie and had one of my gearboxes rebuilt by Mick(Hemmings) and they know Norton's better than most. They are will also give advice and have used them for years and trust their judgement, the shop is only 20 miles from me so I'm fortunate. His DVD's on engine and gearbox rebuilds are a good investment and save a lot of time.

I agree Les is talking bollocks, (he will always disagree with anything Mick recommends!) but I have also had parts from Norvil in the past with no problems.
 
Did a bit of my own research on the bearings this morning. Looks like the NJ306E.M1 vs. the NJ306E.M1.C3 is that the C3 means that it has a larger than normal radial internal clearance. I have no reason to question Angie and Mick, plus other sources specify the C3 bearing, including the INOA site. I don't know why Les is talking like this. I can't seem to find much info on the Timkin MR1306EL, so I think I will steer away from that.

Trouble is Norvil has a real nice complete bottom end kit which includes all nuts/bolts, big end shells, timing chain, gaskets, seals, 2 superblends all for 150 GBP or roughly $228 USD plus shipping. He also will sell me pistons, choice of GPM, JP or EMGO, plus rings for 170 GBP which is roughly what Mick wants for his pistons alone. Now if I can just get him to sell me the C3 bearings with the kit???

Dave
69S
 
MarshalNorton said:
I have a mid year 72 combat, does any other combat riders know when Norton corrected the problem?
Has any one opened up an orig. 1972 and found factory superblends installed?
Click to expand...

If the question is also open to non-Combat riders? Then I can tell you that according to a factory service sheet dated August 1972, the Ransome & Marles (later RHP) 6/MRJA30 roller bearing, designated as "Superblend" was supposedly fitted to engines from serial number 211891.
Also, according to earlier service sheets, a "2 dot" clearance was specified for the previous pre-Superblend roller bearings.

Another service sheet, dated January 1973 deals with the introduction of new "Extra high capacity main bearings..." which were "...capable of carrying a much higher load than any offered before..." so these new bearings are the FAG bearings, presumably, as the new Norton bearing part number is 064118 which has remained unchanged.
 
L.A.B.
Do your service sheets recommend the NJ306E.M1.C3 for service on bikes earlier than 72, like my 69? Les is still suggesting I not use the C3.

Dave
69S
 
DogT said:
L.A.B.
Do your service sheets recommend the NJ306E.M1.C3 for service on bikes earlier than 72, like my 69? Les is still suggesting I not use the C3.
Click to expand...

The copies of the Norton factory service sheets I have do not in fact, specifically mention C3 (or "2 dot") clearance for either the R&M 6/MRJA30 "Superblend", or FAG "Extra high capacity main bearing" although it is certainly mentioned as being necessary for the earlier "pre-Superblend" rollers. That's not to say it wasn't a requirement, just that I don't have any evidence that it was.

The Extra high capacity bearing (part 064118) service sheet does go on to say that as well as replacing the earlier 063906 rollers: "This bearing may also be fitted to advantage to engines of 1971 and earlier models (originally fitted wth a ball bearing as a timing side main bearing)."



John Hudson also mentions the need for "2 dot" clearance roller main bearings in his NOC engine rebuild video, but he doesn't specifically mention that it was a necessary requirement for the 6/MRJA30 or FAG bearing types?

I don't think Mick Hemmings mentions it at all in his NOC engine rebuild video?
 
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