Get out the straight jacket

Hmmm, got here quicker than expected. The box this stuff came in was wet on the bottom and looked like it was thrashed. Fortunately, everything in the box looks to be OK. Only need to do some clean up.

Molnar Crank. I guess it is lighter weight, but kind of hard to tell without weighing the two.
Get out the straight jacket


Molnar 750 Barrels. Nice and very light weight, but come with a nasty gotcha. The sleeve nuts for the 3 studs in the head and pockets for the nuts in the fin areas are the spawn of the devil. Not a clue how I'm going to torque them up or if I can even get them started on the studs. I'll be grinding tools down to get them in there and have to use spacers to hold the head up so I can get the nuts started.

I prefer easy. The old iron barrels are easy. Nothing good comes easy. I shall see if that is true.

Get out the straight jacket


I'll be busy next week.
 
Schwany said:
Both clutches run dry would require that I manually oil the primary chain through the lower inspection hole in the outer primary before longer rides. Would do it every other ride on short test runs..
Click to expand...
I tried that ( long ago..) and I would advise against it.
Your chain won't last 500 km.
Maybe an x-ring chain, like Irkin suggested might work, but I doubt it.
The (dry) chain gets very hot.
Why not a belt drive?
 
Schwany said:
Hmmm, got here quicker than expected. The box this stuff came in was wet on the bottom and looked like it was thrashed. Fortunately, everything in the box looks to be OK. Only need to do some clean up.

Molnar Crank. I guess it is lighter weight, but kind of hard to tell without weighing the two.
Get out the straight jacket


Molnar 750 Barrels. Nice and very light weight, but come with a nasty gotcha. The sleeve nuts for the 3 studs in the head and pockets for the nuts in the fin areas are the spawn of the devil. Not a clue how I'm going to torque them up or if I can even get them started on the studs. I'll be grinding tools down to get them in there and have to use spacers to hold the head up so I can get the nuts started.

I prefer easy. The old iron barrels are easy. Nothing good comes easy. I shall see if that is true.

Get out the straight jacket


I'll be busy next week.
Click to expand...
Lovely stuff!!

Maybe you could get at those nuts with this or similar?


Loading...

b2b.snapon.com b2b.snapon.com
 
ludwig said:
I tried that ( long ago..) and I would advise against it.
Your chain won't last 500 km.
Maybe an x-ring chain, like Irkin suggested might work, but I doubt it.
The (dry) chain gets very hot.
Why not a belt drive?
Click to expand...
I am being optimistic and imagining Al knows what he is talking about. He says he runs the AMC clutch dry in his Seeley. He probably uses an o-ring chain. I might be able to get an o-ring chain to fit, but I'd have to modify a few things. I have tried and o-ring chains don't fit in my primary with the 22T engine sprocket I'm putting back in. The engine sprocket rides too close to the inner primary case. O-ring chains are too wide. The stock Renold chain barely fits and shows signs of skimming the inner primary. I would need to use a thinner spacer around the crank behind the inner primary and remove material on the back of the primary which is already paper thin there. I've been procrastinating on doing that for 35 years.

Smart money would be to buy the wet clutch plate pack for the NEB clutch and live with a leaky primary. That is probably what I will end up doing. I can't bring myself to put that AMC clutch back in there though, even with all new plates. It weighs at least 2X what the NEB clutch weighs.

I haven't been able to wrap my head around using P11 primary covers and a belt drive. I know people have done it, but it looks like too much work making a full perimeter spacer for the P11 primary. And then how does one work around the stator in the outer primary and belt drive engine sprocket issue? Also have to use a Commando mainshaft in the gearbox, right? I may have to look at those old belt drive conversion posts again when I have time to see if any of those issues are covered. Also need to check and see if they actually kept the belt drive clutches over the long haul.

I'm also aware of your belt clutch work using Commando cases on your pre-Commando Norton. That work is above my pay grade. JB weld is the extent of my welding experience.

I'm listening to advice, but am hard headed and tend to make sure things don't work on my own. Thanks for the advice.
 
cliffa said:
Lovely stuff!!

Maybe you could get at those nuts with this or similar?


Loading...

b2b.snapon.com b2b.snapon.com
Click to expand...
Nothing like that will fit under the nut. There is only 1/8" of total clearance for the nut on all 3. There is no pocket for the nut to go up into. The pockets are nothing like they are on a stock head. I'm going to ask Andy how they do it. He'll probably say with finesse. I figure I'll have to grind a wrench down to 1/8" thickness and hope it doesn't break before I get all 3 of those torqued.

I'll post a pic later. Going to clean up the parts first

Edit: I figured out how to do this. Not as big a deal as I thought. I was tired last night and not thinking clearly. I went to take a pic of the clearance in the pocket and realized I can get an open end on the nut and swing the wrench in between the fins to get it started. Looks like just enough room for doing it that way.
 
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Schwany said:
I am being optimistic and imagining Al knows what he is talking about. He says he runs the AMC clutch dry in his Seeley. :eek:
Click to expand...


For about 5 minutes in 20 years (or more)

Anyone who raced using "open" chains had an external manx type chain oiler, and replaced the chain after every meeting
 
Seeley920 said:
For about 5 minutes in 20 years (or more)

Anyone who raced using "open" chains had an external manx type chain oiler, and replaced the chain after every meeting
Click to expand...
Wet clutch pack for the NEB is going to be ordered soon.
 
Schwany said:
I sat on the fence from the get go on the nikasil. He talked me out of buying his cases that the nikasil barrels drop right into. The barrels would need machine work and might be too thin squeezing them into my old cases. It's also possible he doesn't have any nikasil barrels right now with the 73mm bore.
Click to expand...

Andy's next batch of alloy barrels are scheduled to go on sale late January 2023. As they are made to 850 style through-bolt design, they will not fit the Atlas/G15/P11 cases without opening the mouth. On request Andy will provide machining instructions. There should not be a need for machining the barrel. From a technical point of view, coated barrels are clearly advantageous to sleeved barrels, but they require more preparations, which may not be so easy when dealing with Andy. One route possible is to order a semi-finished barrel with a small bore, say 70 mm, and have Millennium Technologies bore and plate it to the exact piston spec. I went this route for an 850 barrel. It's not a solution for those in a hurry, and the total cost is substantial.

- Knut
 
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Schwany said:
OHC is much easier to work with though. I really wish the twin had a chain driven OHC. It would be a dream come true to swap out cams in a old Norton twin in under an hour.
Click to expand...
There actually was an Israeli who converted his Commando OHV into an OHC (or possibly DOHC) valve train. I saw it on static display in the 90's. Israeli members may chime in.

- Knut
 
Schwany said:
Yes, the pre-Commando one "might" work.
I have a spare rear Akront wheel for it if it's 40 spoke. Have not verified any details with Mr Pender regarding measurements. He is not familiar with the P11 anyway. Not many are. It is the red headed step child of the Norton lineup. Anywho... The width between my swing arm at the axle is wider and the axle is a different diameter from that of a Commando or pre-Commando slimline, so I'm not sure if his hub would work easily or at all. The sprocket offset and the narrower hub might and probably would put the rim in a funny location. I also could be over thinking it.
Click to expand...
A rear hub off a 250-500cc cc mx or adventure bike is probably a better starting point. I went with KTM parts off a 690 Duke. The weight difference to old Norton parts (G15 in my case) is amazing. However, the design is clearly more fragile.

- Knut
 
Junglebiker said:
Don't know why I never considered moving the spacers!! Maybe I was concerned about getting the clutch sprocket out of line with the drive sprocket?
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Final drive sprockets will be out of line if you alter the spacers. Then, you have to alter offset of the rear wheel, and .... and ....

Leave the gearbox be, fit a Commando mainshaft, and design a proper outrigger bearing. Add a one-off chaincase, and you have the liberty to either run a wet clutch (+chain) or dry clutch (+belt drive).

I thought alignment was the main problem in your initial attempt to make the NEB clutch work?

Running a chain drive with no or occasional lube will end in a disaster. The chain will shed rollers and snap in the end.

> I think it'll hold up on the street as well as my rear chain does.

Wrong thinking. Remember the primary chain runs a lot faster than the final drive chain. Hence more friction and heat build-up.

If you are determined to run a dry primary drive, go with a belt drive.

- Knut
 
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worntorn said:
Weird that others can get the AMC to hold on a 750 or even a hotrodded 750.
Click to expand...
Glen, I've never heard of that. On the contrary, contemporary test reports of the P11 mentioned clutch slippage, and those bikes were factory prepared bikes .....

The AMC clutch, even the perfomance version introduced for 1962, is exhausted coping with the torque of the big Norton and AMC engines.

- Knut
 
Schwany said:
I haven't been able to wrap my head around using P11 primary covers and a belt drive. I know people have done it, but it looks like too much work making a full perimeter spacer for the P11 primary. And then how does one work around the stator in the outer primary and belt drive engine sprocket issue? Also have to use a Commando mainshaft in the gearbox, right? I may have to look at those old belt drive conversion posts again when I have time to see if any of those issues are covered. Also need to check and see if they actually kept the belt drive clutches over the long haul.
Click to expand...
Jampot editor Chris Read fitted a belt drive to his 650 G12 some 20 years ago, if I am not mistaken without swapping the mainshaft for the Commando version. He also dealth with alternator alignment. I can retrieve the report if you are interested.
G12 and P11 are like two cousins design-wise.

- Knut
 
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Schwany said:
Molnar Crank. I guess it is lighter weight, but kind of hard to tell without weighing the two.
Get out the straight jacket
Click to expand...
Nice piece of engineering. I had expected some novelty features, but it looks conventional. It seems Andy went with a Mk3 bolting pattern for the flywheel and cheek halves.
Bolted counterweights make the crank adaptable to different conrods and piston weghts.
Please do weigh the crankshaft.

- Knut
 
mdt-son said:
Nice piece of engineering. I had expected some novelty features, but it looks conventional. It seems Andy went with a Mk3 bolting pattern for the flywheel and cheek halves.
Bolted counterweights make the crank adaptable to different conrods and piston weghts.
Please do weigh the crankshaft.

- Knut
Click to expand...
About 3.5lbs lighter that a stock crank supposedly. Just put it on a bathroom scale and it weighed in at 19.7lbs. So if a stock crank weighs 22lbs it's 2.3lbs lighter. If a stock crank is somewhere between 22-24lbs it could be about 3.5lbs lighter. I do not know how much my current crank weighs. It is a little lighter than stock, but I'm not sure how much.
 
mdt-son said:
Andy's next batch of alloy barrels are scheduled to go on sale late January 2023. As they are made to 850 style through-bolt design, they will not fit the Atlas/G15/P11 cases without opening the mouth. On request Andy will provide machining instructions. There should not be a need for machining the barrel. From a technical point of view, coated barrels are clearly advantageous to sleeved barrels, but they require more preparations, which may not be so easy when dealing with Andy. One route possible is to order a semi-finished barrel with a small bore, say 70 mm, and have Millennium Technologies bore and plate it to the exact piston spec. I went this route for an 850 barrel. It's not a solution for those in a hurry, and the total cost is substantial.

- Knut
Click to expand...
Andy said he thinks the iron sleeved alloy barrels will fit in the older cases. If not, the barrels will make a nice paper weight until I get some Commando cases. I'd like to avoid working with a machinist if at all possible.

Thanks for the reality check from everyone on running the clutch dry. I won't be running the clutch dry.
 
mdt-son said:
Jampot editor Chris Read fitted a belt drive to his 650 G12 some 20 years ago, if I am not mistaken without swapping the mainshaft for the Commando version. He also dealth with alternator alignment. I can retrieve the report if you are interested.
G12 and P11 are like two cousins design-wise.

- Knut
Click to expand...
I'm interested in that report, too. :)
 
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