Model 7 Reserection

A bit more progress-

Looking good !

How do you do the red pinstripes on the painted rim centres.

That 8" front brake is a handsome big affair.
And almost indistinguishable from the 7" version.
Hmmm.

Hi Al - Nice looking restoration, and you are sorely tipping me over the edge to do the same to my C'do. By sorely, I mean I will be headache-sore after my wife finds out what I want to do!

Where are you in NZ, and do you know of any good frame guys in AKL region (preferably - but beyond if they are stellar)?

At some point when I break it down, I want to have the frame checked for straightness as the PO had broken one of the loops behind the z-plate and it was welded right when I first bought it. The weld also needs to be cleaned up a bit.

Hi Rohan the rims were painted with the frame etc not sure how they applied it.

Hi Gortnipper I am in Christchurch, re your frame I have all ways found your best source of info is your local classic club normally somebody will know somebody!, this is my fourth resto in the last eight years and yes things are getting more expensive and harder to get all the time- when I did my 70S there was heaps of good stuff on ebay, now it seems harder to find but the longer you leave it the harder/more expensive it will be, I also believe the health and safety crap is having a big impact on our service providers i.e. my favourite chrome plater shut his door couldn't be botherd/wasn't worth the bullsh-t.
AL

The gearbox has been stripped and inspected and found to be in reasonable condition all gears are ok though a new set of bushes wwere required along with new bearings including a RLS9-11/4 2RS drive bearing leaving the outer shield in place should help keeping oil in, e also put a rubber lipped seal in the cover where the gear change goes through then reassembly with new gaskets.

I have received most of the motor back from my Engineer, the crank which is still std has been stripped the slud ge trap cleaned out The blocked gallery cleared then reassembled with a new bolt and nut kit , a new set of shells proved that the conrods were out of round giving .005 crank to shell clearance [which explains the silver tape previously used] so the rods were re sized, new brass bush were fitted to the cases for the cam to run in and a new set of main bearings a superblend for the drive side with a high load ball for the timing side probably an ove kill on a 500 but I have used this set up for many years without a problem, then the cases were reassembled.




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The barrels were rebored to 040 with a new set of pistons, so we now have most of a motor.
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Why wasn't the broken fix on the jugs welded and ground properly?

Give im time, its not assembled yet.

Since its only been strongly tacked there, and only the tips of the fins are visible once fully assembled,
only the outer ends of the weld would need to be smoothed off for it to all but disappear.

A different question is how to make the fins not be brittle if they are fully welded back in place,
since cast iron becomes ever so brittle once its been heated to red heat - as it required for a full weld.
Its some sort of (simple ?) chemical/heat treatment process, but I obviously wasn't paying enough attention back when I saw it done.

Thanks Rohan, my engineer was not keen on improving the weld, so as it is not obvious when the head is on it was decided to leave it as it was.

The bottom end bolted into the frame with out problem, then I attached the inner primary-



I had purchased new corks for the clutch drum and a new primay chain, as the previous owner had manufactured clutch plates out of some type of fibre sheet I also purchased a new set of drive plates from BMH Trading in Australia though I was only able to fit four plates in the drum with the clip in place I will try it and see what happens.

As I said at the start of this post this bike had supposedly belonged to an engineer and supposedly had a rebuilt motor, I was even able to locate and speak to this person by phone which allowed me to continue this belief but I have been proven wrong, I have already described what I have found up to now but the cylinder head turned out to be an absolute shocker there were washers under the valve guides [we do not know the originality of the guides but they were not Norton] the valve springs were possibly Triumph as were the spring cups, the head had at some stage dropped a valve as when the carbon had been removed there had been no attempt to repair the damage, so after 4 new valves, valve springs cups insulating washers 2 valve seats 4 adjusters and quite a bit of aluminium welding and machining I now have a useable cylinder head

possm said:

the valve springs were possibly Triumph as were the spring cups, the head had at some stage dropped a valve as when the carbon had been removed there had been no attempt to repair the damage

Click to expand...

Very nice - now.

You have to remember that Norton spares were nearly unobtainable after the 1970s fiasco of the british motorcycle industry,
so depending on when this earlier 'repair' was done, using whatever was obtainable locally was about par for the course.
If someone then could track down by mail order who in the UK had what, then maybe the right spares may have been findable.
(No internet then, took weeks or months to even get a reply).

My earlier plunger frame dommie came with Triumph exhaust pipes, cut'n'rewelded to fit the Norton exhaust port angles.
With a sprinkling of Suzuki, Triumph and all manner of bits beyond that - whatever the local Dealer had that
could be co-opted into fitting and working.
Finding nuts to fit the back wheel axle required running a spark plug tap through Commando wheel nuts.
I was pleased to get them (they fitted perfectly)(ask how the Dealer knew that trick)
or the back wheel had no visible method of staying put, beyond the chain...
Now, 26 tpi nuts and bolts are only a mouse click and credit card number away. Easy peasy by comparison.....

You would seem to be making good progress.
Any ETA for a test ride ?

Thanks Rohan, yes that makes sense as the bike was last registered for the road in 1976, the mileage on the speedo is the same as when the ownership was changed to the said engineer also in 1976. The hold up for this project is the petrol tank, I have decided to go to the chrome finish for the petrol tank, and it took some time to find somebody that had the ability to bring it back to a condition that it could be re chromed said panelbeater has had it for about 3 months but rang me last week advising that it was very close, but will still need chroming and paint.
AL

I had a tank with someone for about 2 years, and then had it handed back to me,
only partly done, so sounds like you are doing well !

I believe these days though that minor dents can be lead filled, and happily chromed over,
so that takes much of the beating side of things out of the work schedule.
Unless you are a perfectionist - as most panel beaters are.

Barrels went on without a hitch

as the original fibre timing gear was showing its age I purchased a new one from RGM motors in England and set about assembling the oil pump and timing chest, the oil pump was stripped and checked with usual ware area's being refaced. in close to forty years working on Norton Twins I have to admit that this is my first generator motor and it took me over two hours to get the cam sprocket to go onto the cam correctly each time I tried there was the rattle of the key falling down the chest, it has to be aligned precisely, in the end I got it-

Magneto timing was also done at the same time.

Looks like a fibre dynamo drive gear.

The magneto gear is available in fiber (fibre), steel, and aluminum. Eash has its own pros & cons. If your fiber gear has worn out, it ether has many miles on it & has served its purpose, is not installed properly, did not get proper lurication (dirty oil, or lack of oil), or it was made incorrectly (China/Taiwan, India).

Fiber gears are still used today & were used on billions of american cars from the Ford model A, clear until the 1980's on timing gears, so the problem with the Lucas magneto fiber timing gear isnt the material.

I have heard several opinions on why many motorcycle manufacturers used a fiber timing gear on the mag. Some say it is so that if the mag bearings fail, you wont strip the steel gear teeth & have the metal go through the engine. Not sure I believe that, because if the mag bearings failed, there would be no more ignition & the engine would stop. Some say it was cost, I dont think that is true either if you consider the labor cost to make the fiber gear, the rivets, the steel center hub, then pay someone to assemble the whole thing, versus making a one piece metal gear. I have heard it was to electrically insulate the armature shaft, that cant be true, as the earth brush takes care of that anyway. I can tell you for a fact, that in manufacturing , the most common use of fiber gears is because they are quieter, and they dampen vibration, that is not to say that is why English motorcycles used them though.

I have seen the brand "Tufnol" used, do we know that that is the brand that was used originally, of is that a generic term for all fiber gears?

For what its worth, here is a current & direct quote from the Tufnol website regarding their gears:

"GEAR DESIGN IN TUFNOL LAMINATES

BENEFITS
Non-metallic pinions machined from fabric reinforced TUFNOL laminates are used successfully in many industries to reduce noise and to damp vibration in high speed machinery and equipment. This application extends from instruments to heavy-duty industrial plant.

Long life TUFNOL laminated gears are hard wearing. They are also sympathetic to metals with which they work and this results in little or no wear on their mating wheels; often the life of the metal wheels is prolonged by the use of a TUFNOL gear in the drive. TUFNOL laminates are unaffected by oil, grease or petrol, are generally suitable for use in corrosive atmospheres and can be stored indefinitely without deterioration. Their mechanical strength, toughness, and temperature resistance exceed those of many commonly used thermoplastics materials and enable them to withstand extremely arduous working conditions, as well as the more delicate precision situations. Their resilience provides good resistance to shock loads and their light weight - one sixth of the weight of steel - reduces inertia, which leads to lower power requirements."

I think it would be interesting to know why it was used & why some people still have thier original timing gears on their high mileage bikes & some people get a short lifespan.
All the best, Skip Brolund.
P.S. I just wanted to point out to you the dangers of using a fibre gear, i once ruined a 500 Velo engine by knocking out the roller big end when the fibre magneto drive gear lost a couple of theeth for the second time, I when over to an alloy gear with manuel a/r after that and suffered no more problems.

Bernhard said:

The magneto gear is available in fiber (fibre), steel, and aluminum.

Click to expand...

Can we point out that dommies have the GENERATOR driven by a fibre gear - with a friction clutch.
The magneto is driven by chains and sprockets ( and the half time gear.)

How is it that Skips name appears on that Tufnol website quote. ?

Something to watch out for is that the fibre gear in a magdyno is not the same as the one in the dommie genny drive,
they are one tooth different (?). Typical Norton/Lucas effort....