The 650 Norton thread

robs ss

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I am in the process of fitting the barrel to the crankcases and have a question.
I have "flattened" the crankcase mouth using a sheet of glass and abrasive sheets (180 grit then 360) and counterbored all threads.
Currently performing the slow and painful task of scraping and filing the mating surface of the barrel using engineers blue.
Started with many gaps up to 8 thou.
Now have only 2 gaps, one in front of the front centre stud (2-3 thou over width of 25mm) and at the front LH corner 5/16" stud (2 thou over width of 20mm)
The further I go the harder it gets as metal needs to be removed over a larger area whilst keeping it flat.
My question is, what gap is considered good practice?
I have read the various threads on merits of base gaskets and "goop" but couldn't find anything quantifying barrel-crank fit.
My current plan is to not fit a gasket and use Threebond grey (worked well on my short-stroke ES2)
Cheers
Rob
 

texasSlick

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robs ss said:
My question is, what gap is considered good practice?

My current plan is to not fit a gasket and use Threebond grey (worked well on my short-stroke ES2)
Cheers
Rob

I would think silk thread (if memory serves, #4) in conjunction with Hylomar or similar "goop" would be adequate to make a good seal.

Sorry, I cannot give you a link on silk thread technique at this time. PM me if necessary.

Slick
 

robs ss

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Thanks Slick. I had not heard of silk thread below. I looked it up on some aircraft forums and found it is used to prevent the gasket compound (goop) from being completely squeeze out of a gasket less joint.
Sounds sensible, so long as the resultant film, including silk, is not compressible over time (loosen nuts on studs)
Cheers
Rob
PS - I'll try to attach photo of the ES2 - nope, no luck!
 

texasSlick

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robs ss said:
. I looked it up on some aircraft forums and found it is used to prevent the gasket compound (goop) from being completely squeeze out of a gasket less joint.
Sounds sensible, so long as the resultant film, including silk, is not compressible over time (loosen nuts on studs)
Cheers
Rob
!

Silk can be used with gaskets as well. Use on side with scored or damaged surface, or both sides.

I know of no issues regarding loosening of nuts/bolts. Silk is the "de riguer" gasket treatment in aircraft engines. Of course, aircraft engines always have security on all fasteners, but if compression we're an issue, it would still occur with secure fasteners. I surmise your worry is that a re-torque would be necessary. In short, I do not think it is an issue.

Slick
 
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beng said:
acotrel said:
I don't know what barrels fit the 650 Norton bottom end, I don't think any other early Norton had twin carbs ?

The 650cc Norton would accept the parts of any earlier Norton Dominator engine, 750 cylinders/heads will not fit though as to accommodate the larger bore the four rear cylinder studs were moved back and the oil drain-back from the head was relocated, the four main head bolts of the 750 were made smaller in diameter and moved outwards too.

The first regular production Norton twin with twin carburettors would be the Model 99 Nomad Scrambler which was built from 1958-1960, twin carbs were also an option on very late 50s wideline Dominators though.
The 650 Manxman was the first model with the 89mm stroke crank and 1 3/4" crankpins though and the down-draught head. The Atlas and 750/850 Commando were the same as the 650 except for the changes necessary to increase the bore from 68mm to 73/77mm.

The 650 Norton got it's legendary reputation for a few reasons. It was first only available to the USA, which gave it a bit of mystery in it's home market, then when it appeared for sale in the U.K. labeled as the 650ss it tested in magazines at a higher performance all around than the Triumph Bonneville. When the Atlas initially came out in the USA, then in the U.K. a year or so later, it not only had a much lower compression ratio, but was initially supplied with a single carb, so it was not aimed at the performance crowd, plus it's heavier pistons made it shake a bit more too.

Once the Atlas came out in late 62' the 650 was not marketed in the USA too much and sales were very small in comparison. Since the Atlas was not available in the U.K. until 64' the 650ss stayed at the top of the Norton range there and did really well in racing.

Dunstall and others eventually got the bugs out of the 750 and made it fly, but when the Commando came out for 1968 with improvements in it's engine for durability and a lot of marketing hype, the 650ss and 750 featherbed bikes were pushed out of the limelight and faded away.

The motorcycling enthusiasts of the early 60s never heard anything but praise for the 650ss, while the 750 Atlas had a reputation of being slower, vibrating more and having a few bugs like blowing head gaskets and weak cylinders.

So the 650 Norton was a unique package of power and handling just long enough for enthusiasts to notice it's successor's were not so well rounded in comparison. It was the high-point and flag-ship of the original Norton works which was dissolved after 1962.

Presently any 650 Norton is a rare bike. They were made in low numbers to begin with, used hard and blown up then used as raw material for the making of various specials. Any that are left intact are much harder to find top-end parts for than the later 750/850 bikes. Aside from the small bore, most any Commando upgrades/parts will fit giving similar performance and power/reliability.

Some year-by-year 650 Norton facts:

1961 - First official model year. Almost all of 1961 production sent to the USA with the bikes painted almost all blue with red seat covers, small capacity fuel tank, seat moved forwards to suit. Introduced as the "Manxman".

1962 - initial production still sent to USA in the form of all blue/red seat Manxman bikes. 99 of the first 100 650ss bikes were sent to the USA, About half of them looked identical to a Manxman except for having black seats and engines stamped 650ss above the crankcase breather, the other half were still blue but had black frames and seats. Some later 650ss bikes shipped to the usa had the small Manxman tank but the black/silver paint. First year for 650ss and ONLY year it was produced at the original Norton works, a special bike....

About 560 650 Nortons were made before 650ss production kicked in for the 1962 model year, these were the original usa Manxman bikes, by the end of 1962 a bit over 2000 650 Nortons were made at the original Norton works before they were shut down, rare bikes....

1963 - Production small due to parent company AMC abandoning the original Norton works and laying off all workers, moving production to the Matchless works. Specification very similar to 1962 models while AMC used up old Norton stocks of parts. I am not sure at this point if any of the bikes made at the original Norton works late in 1962 were manufactured as 1963 bikes, it may have happened, the Norton records hold the answers.

1964 - 650ss as previous except for many small detail changes to cut production costs. Previous satin-chromed/show chromed hardware largely eliminated for zinc/cad plating. Steering-stop welded on instead of bolt-on. fuel tank filler moved to right side of fuel tank. Smiths Chronometric instruments replaced with magnetic grey-face. Parts detail, material changes from use of new machinery, tooling and jigs too many to list. The later AMC Dominators were not any less functional than before, they were just not to as high a finish and looked a bit more like consumer goods than works of art.

1966 - Continued changes. Upper rear engine plate mounting welded in instead of through-bolted. Oiling system improved with double-speed oil pump gears, larger oilways and pressure-fed rocker arm spindles. Spigot sealing cylinder to head eliminated.

1967- onwards. Amal Concentric carbs phased into production. Head castings same yearly as Atlas and Commando just machined differently for smaller bore etc.. Last hurrah is the single-carb Mercury touring bike sold through 1970, oddly outlasting all other pre-Commando Norton models.


HERE SOME NORTON FACTORY RECORD FACTS THE FIRST BATCH OF 650s WERE BUILT FROM NOVEMBER 7th 1960 FROM NUMBER 18-93601 shop number 7 it was pulled off the line before the shop number was stamped on and shop numbers are not in numerical running order . So Number 18-93602 was shop stamped number 1 the model stamp number was 65 or 65c custom or not has standard with extra parts fitted or altered by Norton has customers has asked for at the time, the Rarest 650 Norton's Are NORTON MANXMAN , STANDARD AND NORTON DE_LUX, 650 De-lux Stamped marked 18D on the outside of the left-hand crankcase these Norton had a short build run, less than 600 built most of the Standard and De-lux models were exported to Iron curtain country's
 
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anyone using Venhill throttle cables if so which one did you order for twin concentric amals on a 650ss / atlas :) they were a bit confused with there own cables as to which ones are mono bloc and concentric


Cheers,

Tom
 

robs ss

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I bought the Venhills cable making kit a few years ago and have found it to be excellent value for me and my friends.
It covers all the cable types and different ends - even warns of importance to "birds nest" inners in high tension cables (brake, clutch)
All in all I have found it excellent and comforting in case of a failure
Cheers
Rob
 

robs ss

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Looking for advice on a 650ss head (1964)
Looking down the exhaust ports I notice a lump in the lower inside quarter of both ports (see photo of LH port)
Anyone else notice this? May be extra material to cover the head-barrel stud below exhaust port?
The lumps can't be good for gas flow.
Anyone tried grinding them off? Risk of breaking through to stud??
Cheers
Rob
 
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Measure the performance before you grind it off,
and then measure the performance and see how much you lose !

The Commando page has extensive chat on the smaller ports used in the newly cast Fullauto cyl heads,
and how beneficial this has been. Bigger is not always better in the world of gas flow, it seems ...
 

robs ss

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Yep - I'm aware or that.
There was a George Mansfield (Meszlenyi) in the UK (unfortunately died 2006) was producing ports similar to Fullauto well prior to their existence (see photo below)
So there is no doubt filling in the floor of the port is beneficial - I don't intend to go to this extent (yet)
My query was whether this bump was unique to my head and, if not , what others may have done about them, if anything.
Cheers
Rob
 
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Are the bumps in both ports ?

Even if other folks don't have them, it could be some unknown tuners' secret trick to getting the exhaust flowing better than stock (!!). Unless you try them before grinding them off, may never know.

There is a famous history and story of Nortons tuning tricks and head/port shapes.
Back prior to WW1, all Norton engines of some models were tested around Brooklands track, in a slave frame kept exactly for that task. The Brooklands Road Special in various models was certified to have done 75 or 80 mph - some engines were faster than others, some considerably. The really quick ones were put aside, and the head and port shapes studied to see why this may be so - through variations in the castings - thats how better combustion chamber shapes and port shapes/lumps/bumps were arrived at.
 
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I thought I'd posted this story about my works 650SS before, but I can't find it.

I was provided the bike for my ride-to-work, about 45 miles. Public transport for the trip would involve two buses, then a train, then another bus and would take about 2 1/2 hours each way. The Odometer showed 132,000 miles when to took it over, but I have no idea if it was true. I had no problem in the first couple of weeks, then it blew a head gasket on the way to work. I fixed it during the morning and it ran very well.

About 6 months in, Plumstead requisitioned it back to do some single carb tests. Sidecar people were highly ticked that the Commando couldn't run a sidecar. They reassembled it and shipped it back after the tests were done, and I was very happy to give up the 50cc 2-stroke Motom and the Villiers-India scooter I'd been riding and get back on the 650. I set off home the first evening after it came back and was threading my way through downtown Wolverhampton. I typical Brit fashion, I was weaving through the slow, rush hour traffic. I whipped out to pass a slow car, then had to pull in again behind a double-decker bus. Whe I rolled off the throttle, the engine stayed at a high power setting. I was saved by the fact that it was magneto ignition and had a kill button.

I limped home about 8 miles using the kill button to control speed. I got the shop to send the team van out the next morning to take me and the bike in. Stripping down the carbs showed one slide almost full open. Apparently, whoever re-assembled the bike at Plumstead didn't realise the slides were lapped to fit the carb bodies ahd they'd been crossed over. Plumstead hadn't run the bike after putting the dual set-up back on. Once fixed, I rode that bike for the rest of my time at N-V. On my final run before I left, the oil-tank drain plug fell out when I was cruising the M-6 freeway at 85 and the engine seized. In the run-down of N-V in 1968/69, I don't think it was ever fixed.

Someplace, I have a photo of my two daughters sitting on the bike at home. They were 4 and 2 at the time, now 51 and 49. I'll try and find it and post here.
 
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NORTON FACTORY RECORD FACTS the First six Unified 650 twins are built in 1959 3 went to Plumstead and 3 stayed in the experiment department one was tested at MIRA and found to over heat not much development work was done on these engines, but from what is known they were all short stroke engines and used a 1.75 crank journals now two have been rebuilt and fitted to respective Norton frames and running gear by a club member the First Production 650 was the named by Joe Berliner and styled by Jay-be -Sach a Ducati stylist the first machine were built on the 7th of November 1960 the first batch was sent by January 13th 1961 330 machines in all , the next batch was in march of 1961, the third batch in early august 1961 and the last of the Manxman model and the start of the 650ss which was a economy model of the Manxman in black and silver
 
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Are we just randomly posting and reposting random facts here, some with no punctuation
all jumbled up and intermixed with other posters posts, some rather ancient. ?!
Will take some rather skilled detective work to sort sense from that lot....
 

L.A.B.

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Rohan said:
Are we just randomly posting and reposting random facts here, some with no punctuation
all jumbled up and intermixed with other posters posts, some rather ancient. ?!
Will take some rather skilled detective work to sort sense from that lot....

As those posts by annajeannette were such a lengthy jumble of reply and quoted text I've deleted them.
 
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worn torn said:
Anna, can you tell us how many of the 650ss bikes were built over the years?


Glen

yes not many has the Commando or the Manx come to that there is more Manx machines than you may think
 
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HELLO All If you own a 650 of any model then you are one lucky owner has there is not many left out there And I think it was one of Norton's Best of the Bunch So hang on to it and look after it to treat it with some respect
 
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In my time I've owned about 35 motorcycles, not many by some standards but all of mine have been ridden a fair bit. Of them all, the 650SS was my favourite. Not necessarily the best but my favourite. It had a wonderful blend of performance, (relative!) smoothness, handling and steering, and reliability and soul. Some aspects were better than others.
Even today my perfect everyday motorcycle to ride off into the sunset, would be a more or less standard 650SS, with a decent disc brake on the front.
cheers
wakeup
 
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anyone got any tips for cable routing :) trying to figure out the correct route on the throttle an air cable for my 67' 650ss :) 930 amals

an anyone got any tips for setting a 2ls up all the adjusters have been nocked oooops so its not working right guessing you have to set it with the hub of the bike?


Thanks in advance,
 
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Hi everyone, gonna do the first start up on the new carbs with the 650ss at weekend

quick question regarding setting the throttle stop screws for idle,

do you go in with them till you just see the slide move ever so slightly



or best going in all the way then back out a turn got about 1.5 turns of effect on the slide with them

premier concentrics
 
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