Who made these barrels?

Why not cast alloy Norton cylinders, with a view to having Nikasil bores? It would then be possible to run closer bore clearances, and wear would pretty much be eliminated as long as oil was changed regularly. Forged rather than cast pistons would also be a good idea, and would work well in a modern Nikasil cylinder.

Nothing against that plan, but most of our customers want original parts. Plus you need different piston rings (chromed), different pistons probably, and if desaster strikes you can throw the whole barrel into the bin- no oversizes, no rebores.
Hence not something we as Andover Norton want to do.
Joe

Nodular iron rings work perfectly in Nikasil cylinders, and problems seem to be few and far between on modern machines, the majority of which use Nikasil cylinders. However any plated cylinder which does get damaged for any reason is in most cases easily repairable, although this is obviously more costly than a rebore and new pistons.

Diabolical little model aircraft engines have gone to " A.A.C. " raceing ones .

Hard Chrome or Plasma Coated bore / nikasil . Originally A.B.C. silicone Alloy , Brass sleeve ,hard Chromed .
The expansion co-efficents do wonders for preventing siezures under duress . 20 + 000 rpms , 30 to 40.000 common .

So , Nikasil LINERS in a Alloy Barrel would get the heat transfer functioning . The Olde Bristols found centrifugally cast
liners essential for their sleeve valve engines , as did Napiers in the Sabre . Giving consistancy of density / hardness .

Did you have any complaints about the Alloy Commando Barrels . Dunstall sees to have got away with his 810's ??
Presumably a thicker wall about the sleeve , and a high durability alloy would do wonders, even if the base nuts
were a swine to tighten .

Will start on about waffle irons , the Iron H.D. 750 XR , the alloy ones are reputed to be about 90 / 100 H.P. now .
Though theyre a ' Obsolete pushrod Twin ' , so obviously no good ! :roll: :| :mrgreen:

Matt Spencer said:

Did you have any complaints about the Alloy Commando Barrels . Dunstall sees to have got away with his 810's ??
Presumably a thicker wall about the sleeve , and a high durability alloy would do wonders, even if the base nuts
were a swine to tighten .

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I heard good things about the 810's in the early 70's in my little corner of the world however there have been numerous reports of liners cracking at the slots for the rods here on this forum. Later 810 barrels went to a curved cut out rather than the square one. I've wondered if nikacil coated alloy sleeves would work. At least the rapid heat expansion would be similar through the walls. I'm wondering if it's the temperature difference from top of the cylinder to the bottom that is the problem and if alloy sleeves could overcome it.

The 850 Norton was developped from the work done by André Burke from Montreal, he had a 900cc 750 in the early seventies. the factory flew him and his bike to the UK to see how he did it and they gave him a 750 production racer in exchange for his 900. I am not sure if he welded up his cylinders, but that could have been one of his. I will ask my friend monday, there is a good chance he remembers how ihe did it.

Jean

Thanks Jean , sounds a intresting bloke . Got a camera , has he any norton pictures ? ?

The silicon alloy piston , chrome brass liner was invented by a italian Garafori about 1970.
Their 10 cc engine pulled about 20.000 rpms & excedded 200 mph back then .

The thing runs ringless , and has a ' tapered bore ' looser lower down , straighter where the rings'd run , and a slight
interferance fit at tdc . Heated before starting new , by some . The liner expands instantaeneously from combustion
heat. Most run Methanol , but some classes add Nitromethane . differant fits reqd. per fuel .

The AAC , silicon alloy piston , chromed alloy liners are normally refered to as ' Plasma Coated ' , apparently the Russians
are pretty good at it , and it uses a bit of electricity to do . Short cuts or cheap & shoddy would be just that .

The AAC is a few decades post ABC . Differant tapers are employed say Raceing ( Hard out max revs ) Vs Aerobatics.
Though generally all ringed engines run a Parrallel bore .

Silicon content and expansion rate are related , and ' grainy ' silicon aluminum abrasive . Quality issue again .

Pressumeably a few thou taper ( 1 - 10 ? ? ) would result in parralel surfaces at operating temperatures giveing optimum
lack of ring drag , if not seal ? ? . obviously soft rings would be sacrificial , hard ones incompatable .

FWIW, Kenny Dreer built some Commando engines with his own alloy cylinders without liners. They were finished with some sort of modern coating, maybe nikasil or one of the other similar processes. I don't know how many he built, but probably not a lot, and I have no info on how well they worked. I bought some of the leftovers from him without the bores coated, and was planning to bore them out and fit conventional iron liners in them. They look like they have significantly more metal in some areas than some of the other alloy cylinders I've seen, so should be good for larger bores. The only drawback to them for me is that they use a one-piece bolt-in bit to locate the stock Commando lifters, and I only have one of them. I will need to make copies for the other cylinders before I can use them. Other than that, they look like pretty good pieces. You'll notice that they use six through-bolts, similar to the cylinders designed by D. Robertson in England some years back, but without the bolts being exposed as in the Robertson cylinders.







Ken

Ken,
I used a pair of cast aluminum sleeves in a set of the barrels you had made up several years ago. I got them from LA sleeve and had them coated by Bore tech. They worked Ok but some bore distortion was evident on dissassembly. I used the 1mm ring package and didn't have ring sealing problems. They definately ran cooler. I couldn't even get the oil to change shade. I just used them on the track. Jim

Thanks, Jim.

I have never tried aluminum sleeves, although I've seen them in Yamaha TT600 singles. They used an aluminum sleeve and chrome rings. What clearance did you use for the aluminum sleeves? The Yamaha ones were just an easy push fit.

I might look at having Bore Tech do the bores of the Dreer cylinders. I have to check them and see how large a bore I can get wuthout sleeving them.

Ken

Ken, I only did it once. I used JE pistons and set them up at .0035. Might have been able to go tighter but it worked fine . I installed the sleeves with less than .001 interferance. They dropped in and rattled around with the barrel hot but grabbed ahold in just a few seconds. No second chances. I still have the barrels and will probably use them on my dual sport N15. Jim

Is it true that Kenny Dreer had to delete the headsteady and replace it with the third iso because the alloy cylinders were distorting due to the loads on them from the HS? I've wondered about whether torque plates would be of any use for boring/honing Commando cylinders. I guy I knew told me no, but it would be a different story if they were alloy.

rpatton said:

Is it true that Kenny Dreer had to delete the headsteady and replace it with the third iso because the alloy cylinders were distorting due to the loads on them from the HS? I've wondered about whether torque plates would be of any use for boring/honing Commando cylinders. I guy I knew told me no, but it would be a different story if they were alloy.

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I use torque plates on Norton cylinders. 850 cylinders don't distort much but 750s distort quite a bit near the head bolt holes.
With aluminum cylinders it is a must. Jim

rpatton said:

Is it true that Kenny Dreer had to delete the headsteady and replace it with the third iso because the alloy cylinders were distorting due to the loads on them from the HS?

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I think it was more likely from changing to an OIF.

rpatton said:

Is it true that Kenny Dreer had to delete the headsteady and replace it with the third iso because the alloy cylinders were distorting due to the loads on them from the HS? I've wondered about whether torque plates would be of any use for boring/honing Commando cylinders. I guy I knew told me no, but it would be a different story if they were alloy.

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I use torque plates for boring and honing 920 cylinders, both for iron cylinders sleeved to 920 and for alloy cylinders originally sleeved to 920. I found back in the late '70s that they were esssential for getting any kind of ring seal at the top of the stroke with stock iron cylinders sleeved out to 920.



Ken

ZFD said:

Bernhard,

You may not believe this but the Domiracer story is one of my special interests and I have spoken- eye-to-eye resp. by e-mail- with Paul Dunstall, who got all the bits left from the Birmingham Norton factory, Rudi Thalhammer, the only person to ever get a genuine one out of the factory (bad conscience present from Doug Hele), and Mick Hemmings, who still hopes to get one together and has some original leftovers.

I know they had an ally barrel and that it was Nikasil plated in Stuttgart. However, this was the only incident Norton did it- and it is quite simply the way to go with an ally barrel, as I said. What you probably don't know, not a single part inside that engine was not special. Barrel, head, crankcases, crank, camfollowers, pistons, you name it it wasn't even based on production stuff.
Joe Seifert

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I am aware that the alloy barrels were special, as were all the other parts; I still have not fathomed how Norton made those cam followers with the pushrod cups inside, just above the base of the cam faceplate.
I have a hunch that a least one of the 500 Domiracers was a short stroke engine as it used, at that time, the 650 Manxman cylinder head.
I was contemplating making a 500 racer with a lowboy frame, the special crankshaft can easily be made to order, but the con rods and pistons with the single Dykes L shaped piston ring would be slightly more difficult & expensive to obtain. As would be the eccentric adjusted rockers, these would also have to be specially made.
The Domiracer I saw was ridden by the late Ray Pickrell in the late 1960s but it had lost it’s GP carbs by then, and was eventually withdrawn by Paul Dunstall, who had spent a lot of money developing the ‘’ Drainpipe’’ 750.

Carbonfibre said:

Not heard of plasma sprayed cylinders..............sounds impressive.

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Well in the grand scheme of things nikasil is old technology, it isnt that much better than cast iron and from memory it has corrosion problems with some fuels. The range of coating properties available with a plasma spray is massive, as the coating starts out as a powder which is melted in a plasma before it impinges on the cylinder wall.

This coating has much better wear and scuff resistance than nikasil, it will also run well with TiN coated rings, nitrided SS rings etc


This particular coating has a solid lubricant in it....

Wonder which of the major motorcycle manufacturers are currently using plasma type cylinders?

Carbonfibre said:

Wonder which of the major motorcycle manufacturers are currently using plasma type cylinders?

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Maybe you could ask a few and get back to us on it?
Or just try Google, you will have to look for a few terms though, such as thermal spray, ceramic composite etc

Didnt think any of the major manufacturers used plasma type cylinder coatings currently? Kawasaki tried this a few years back as the process was cheaper than plating, but rapid wear was a big problem, and the recognised method of dealing with this was a plated finish.

http://books.google.co.uk/books?id=kuYF ... ms&f=false