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What is the difference between a Manxman engine and 650SS engine?

ok i know i am opening up a can of worms here but i am only familiar with the norton atlas /750 and 850 commando engines and i would like to know if there is anything special in a manxman engine?,its just the engine i want to know about regards nick

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when will your book be out ANNA J ? will it list the exact differences between the 650ss and the manxman engine? i'm not interested in personal opinions or how high the handlebars are etc etc etc just the engine regards Nick

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Previously nicholas_marshall wrote:

when will your book be out ANNA J ? will it list the exact differences between the 650ss and the manxman engine? i'm not interested in personal opinions or how high the handlebars are etc etc etc just the engine regards Nick

Well it will be out when its ready !

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Previously paul_webb wrote:

It seems as if AJD is just trying to find the holy grail in what is so special about a Manxman. She states that she is going to write a book about them? All of one page I suspect? and I hopeshe has it proof read first.

We have been requesting a book on the Norton Hycam motorcycles(P11's, N15's etc)from Anthony Curzon for some time as he has a wealth of knowledge and information' and this I am sure will be well worth waiting for as they can be classed as special build and built for a purpose.

Just wait for the same old reply of utter jibberish.

ATB, Paul.

Well as for proof reading someone need to proof read what you and what other have put before trying to take the Mick out of me, And if you read what I put earlier you then read that this Book on Rare Norton twins , and not just one motorcycle, some of you would not know a Rare Norton If you fell over it ! yours Anna J

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I did consider listing all the difference between the Manxman 650 and 650SS but this would take pages and pages. However, just to demonstrate the attempt by the factory, at the time, to use existing chunks from other machines. The attached photo shows a 1960 barrel from a model 99 next to a genuine Manxman 650 barrel. Both have the same casting number 22709. The 99, 99SS and 650 cylinder heads also shared the same casting number 22707.

Of course each model had slight difference in the machining to suit the intended use. In the case of the Manxman barrel you can see the cutaways in the cylinder skirts to allow for the greater crankshaft throw. What is not so obvious is the 3mm difference in the length of metal below the crankcase flange. The Manxman barrels have slightly longer pushrod tunnels and cylinder skirts (spigots). By the time that the 650SS (or Manxman Mk2) hit the road these difference had gone. What I can not say is whether the early UK standard 650 or de Luxe models had the extra 3mm as well. The casting number 22709 hung around until after spigotless barrels became the norm and the casting number then became 22710.

To add to the mix and match fun people have trying to restore the 650 model. In its 10 year life, the engine was crowned with 4 different heads.

Attachments 99-650-barrels-both-22709-jpg
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The mention of 'Rare' Nortons could open a 'can of worms' in this thread. Unless a Norton has been kept exactly as produced by the factory, then the slightest of alterations could make it unique and therefore rare. All of my Nortons are tailored to my own needs/specifications and as there are no known replicas must be rare.Anyway......if we stick to post 1960 Nortons not generally seen in the UK. In the rareity list might be a P11, N15, 750 Scrambler, Commando High Rider and a few others. Back in 1998, I was also fortunate in being asked to test ride the C652SM (Supermono) International. A very interesting single. Not many were built and I have never seen one on the road or even at a UK rally.10 years later and I got a ride on a 961 courtesy of the first roadgoing test machine and the prototype of the line that followed.I hope that it has been kept as it is very special.Manxman 650s......I have now seen 5 in the UK and understand that despite the fairly low production run there are still a good number in the USA either on the road or derelict in sheds and garages.The one Norton I would like to see up close is the Mark 1 Atlas. There were probably less of these built than the Manxman. Most, if not all, going for export. Other suggestions for rare post 1960 rare Nortons welcome.

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Previously anna jeannette Dixon wrote:

Previously paul_webb wrote:

It seems as if AJD is just trying to find the holy grail in what is so special about a Manxman. She states that she is going to write a book about them? All of one page I suspect? and I hopeshe has it proof read first.

We have been requesting a book on the Norton Hycam motorcycles(P11's, N15's etc)from Anthony Curzon for some time as he has a wealth of knowledge and information' and this I am sure will be well worth waiting for as they can be classed as special build and built for a purpose.

Just wait for the same old reply of utter jibberish.

ATB, Paul.

Well as for proof reading someone need to proof read what you and what other have put before trying to take the Mick out of me, And if you read what I put earlier you then read that this Book on Rare Norton twins , and not just one motorcycle, some of you would not know a Rare Norton If you fell over it ! yours Anna J...........................ANNA J when you are ready to have your book proof read i would enlist the services of a MR Stanley Unwin regards nick

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One thing that puzzles me here a bit is Sophie's assertion that the steel sleeves which were'pressed into the inlet tracts were actually to simply sleeve down said tracts in order that smaller venturi carburettors could be fitted.' Sleeve them down from what? This was the first 650 that Norton produced, so what carburettors were these 1 1/16" ones replacing?

My chosen bedtime reading at the moment is the Amal Carburetter Company's application list.... yes, I know! However, it says that the Manxman had 1 1/16" twin Monoblocs, as did the 650SS. However, it says that from 1967 the latter were fitted with 30mm Concentrics; quite a big increase; about 3mm, or 1/8" in old money, especially given that Concentrics were meant to be a bit more efficient than Monoblocs. So, if larger carbs were no problem then, what was the problem in 1961, that smaller ones needed to be hastily substituted..... from what, again?

An acquaintance who has an early 650SS mentioned that his has these sleeves, whilst my 1964 engine does not. Should it have? The inlet ports on mine are 1 1/8". Is that standard for a '64 engine?

Picking up on your point, Phil, about various models of rare Norton, in particular the Mk1 Atlas, there is a picture of one on page 73 of Roy Bacon's Norton Buyer's Guide, looking very much like a Manxman, but no rev counter, a single carb and what appear to be standard UK-type silencers, along with the more subdued finish of black and silver, as per the 650SS.

Another rare twin is the Commando 750 Proddie Racer, of which only 119 were built. I am fortunate enough to have one, although not up and running at present.

Cheers. Ian.

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Hello Nicholas,

You are going back a bit when you recommend Professor Stanley Unwin as a proof reader. Same era as the Manxman. He could easily be related to Anna but a brilliant choice.

Patrick

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On Page 109 of Steve Wilson's 'Norton Motorcycles from 1950 to 1986' he says..."the inlet passages had originally been of 1 +1/8" bore, but these had been sleeved down by the makers to the lower figure to aid midrange power and Syd Lawton for one found that competitors who tried to run with the sleeves removed and marginally larger 1+1/8 carbs were not as fast as his bike with the standard head"Is the Concentric really more efficient? It's cheaper to make, but the bore on full throttle isn't a clean tube like the Monobloc. But maybe the rough interior (under the slide) is better for fuel atomisation?The sleeve isn't as well supported so it's more sensitive to wear. By the time the Concentrics were added to 650 it must have been because of cost, availability, and the Commando was just round the corner anyway.
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That is interesting, David. I can't say that the Concentrics are more efficient; that was the propaganda that was trotted out. Fact is they were cheaper to produce than Monoblocs, which were being phased out anyway, so manufacturers had no choice. It is more efficient from the point of view of float bowl position, minimising fuel starvation whilst cornering. This does not explain the increase in choke size to 30mm, assuming the Amal book is correct. Norton would not have fitted 30mm carbs to 27mm inlet ports, for sure, and that would mean an enlargment from the 28.5mm of the original ports, before being sleeved.

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I have a book of reprints of US 'Cycle World' reprints from the early 1960s. Interestingly, in their test of March 1962, they said the following:

"...our only adverse comment is that the engine does not seem to have quite as much power as the sales brochure would lead one to believe..."

In all fairness, they went on to wonder whether they had received a bad one.

They didn't like the handlebars either: "...these seem to be an Englishman's notion of what an American likes...they force the rider to sit up so straight that the wind is a bother..."

In March 1963, they tested the Atlas:

"...we are pleased to report that it is even better than the Manxman...

The Atlas is if memory serves us correctly, a less fussy machine than was the Manxman; more willing to run very slowly and more agreeable about starting when cold It seems to be utterly without temperament..."

Did they ever test the 650SS which would be a better comparison ?

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Did they ever test the 650SS which would be a better comparison ?

In the US, they possibly assumed that they did not need to as the twin carb Manxman 650 appeared to have the same engine as the later 650SS. (or Manxman Mk2) There are a number of UK tests, available, dated around 1962.

The odds are that nobody else would have spotted any differences either unless they happened to work on examples of both engines at the same time.

The inlet sleeve issue is quite interesting and controversial. One of the factors that helps in getting maximum power from an engine is a big carb. It seems to work on the Commando where 30mm became 32mm and then up to 36mm if you went for a single carb. However, it had the opposite effect on the 650SS, with high top speed but very poor low speed running.

I suspect that Factory wanted to outrival the competition in the power stakes, hence the special engine features of the export Manxman. So the cylinders heads had the bigger inlet tunnels for those who wanted speed and sleeving for those riders who wanted easier riding around town.

The first 650 Nortons released on the UK market were the Standard and De-luxe models both with a single chunky 1&1/8" Monobloc. Plus manifold and porting to match. But by then the lure of smaller twin carbs was greater than common sense suggesting a bigger single. You could always upgrade.

Contrasting this was the Mk 1 Atlas which relied on a tiddly 1&1/16" Monobloc to give it some oomph. This allowed the Atlas to have wicked acceleration but not keep blowing head gaskets.

Grotty brochure pic of Mk 1 Atlas attached.

Attachments 1962-63-atlas-mk1-export-jpg
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Handlebars are just what they are handlebars low ones, in the middle ones, high ones , the ones on my bike are just right for me and my size and there ok at any speed too you don't seem to get alot of wind in your face as you may think, and with me wearing a full face Bell helmet I feel very little in the way of the wind force on me or my helmet , and my bike as a single carb low down toque and a good top speed witch I ever seen yet , only got to 110mph . but there was lots left over on the throttle but my bike as a big engine sprocket on it keeps the revs down and makes the bike more long legged on a long run , but she a fast bike with handling to match one bike I going to love for a very long time, a bike I am more than happy with, and you can keep all your modern bikes this one for me its one I can manage and look-after, AS for Manxman VS 650ss , in performance and engine looks there not much in it , until you try rebuilding one then and only then you see that there very different in lots of ways small but different they are there, and that what I like about Bracebridge Street motorcycles they may look the same but there not , no two bikes are alike , there is that something different about every one, Do not for get I had a Model 7 to a Atlas and Mk2 commando In my time out of all of then there only two I real get on with well and they where the 99SS Cafe racer with 5 speed Quaif box twin Gardener flat side carbs , And My Manxman . And I have a 1954 Dominator 88 as well which I going to see what it like later on now it back in standard mode , it had been a cafe racer but with my having Arthritis well my cafe race days are well over with , a standard bike looks the best anyway , And I never did like the look of something cobbled to gether like a cafe racer ,bits stuck anywhere, or and best bit thrown away , and now very hard to find, now you what to put one back to how it once looked, But that was the trended back then to have a cafe racer , and for some it still is , but for me its all over, I need something very comfortable to ride , Thats where the Manxman is in a class on its own , with styling all on its own that's something I just like, and its was built by hand in bracebridge street Price-less , True art, And gem in a big motorcycle world

And its too bad we all cannot have one, as in my Norton Manxman register there is only 36 come to the light of day, and less then 10 in this country , so there very not many out there , yours DJ anna j

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Hello Phil,

You seem to have a comprehensive knowledge of the Big Norton twins and I was very interested in your statement that the inlet sleeve was easily removed for those who wanted top end power and max performance at the expense of loss of low speed tractability. I suspect that if the sleeve was removed the Norton factory almost certainly rejected warrant claims for blown up engines on the grounds that you've been racing it !!!..

BMC were quick to reject warrany claims with the 1275 Cooper S even though they(Special tuning) supplied the competition parts and encouraged you to compete and even carry Special Tuning stickers on the car.

The US Berliner advert for the Manxman dated December 1960 -Anna's attachment way back in this thread- quoted 52HP @ 6000 rpm. That seems low max rpm for a sports bike and to make use of big inlets/carbs/wild cams you need high rpm. Did the 650 become fragile at high rpm?. What do you regard as max revs for a 650?

Patrick

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Previously patrick_mullen wrote:

Hello Phil,

You seem to have a comprehensive knowledge of the Big Norton twins and I was very interested in your statement that the inlet sleeve was easily removed for those who wanted top end power and max performance at the expense of loss of low speed tractability. I suspect that if the sleeve was removed the Norton factory almost certainly rejected warrant claims for blown up engines on the grounds that you've been racing it !!!..

BMC were quick to reject warranty claims with the 1275 Cooper S even though they(Special tuning) supplied the competition parts and encouraged you to compete and even carry Special Tuning stickers on the car.

The US Berliner advert for the Manxman dated December 1960 -Anna's attachment way back in this thread- quoted 52HP @ 6000 rpm. That seems low max rpm for a sports bike and to make use of big inlets/carbs/wild cams you need high rpm. Did the 650 become fragile at high rpm?. What do you regard as max revs for a 650?

Patrick

Now I do wish folks read my thread before making comments , now I will tell you once again , Norton Fitted these Sleeves To increase power and not the other way round , have you lot not learnt anything about how a Carburettor works and how jet engine work , well there both very similar you have a tube where holes are drilled in right places and air and fuel can mix then this air and fuel mixture is the compressed into a smaller space so this speed up the flow of fuel and atomises the fuel as well before its then compressed by the piston , this makes for better detonation

and better power out put , Now the 650 was tested over a 3 weeks by One Doug Hele and Bill Pincher on a test bed it run at 9000 rpm for very long periods of some 24hours then tested at 48 hours at rpm between 6500rpm and 9000rpm and nothing tell go nor there where any seizures, So there you are , later on they machined the cylinder head to do the same thing in the inlet tracks so then there where no need for these sleeves , that why you have cylinder heads with different casting numbers so they all been doctored in some way and barrels number have changed too this just shows something was going on there , To my mind they where making things more easier to make so there for less money too make, you always follow the money,!!! And Norton made a real good motorcycle then they tried to make it even more cheaper , so in a round about way , Sophie was right saying the Manxman was a test bed -But what a good test bed to start with yours anna j

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Previously David Cooper wrote:
On Page 109 of Steve Wilson's 'Norton Motorcycles from 1950 to 1986' he says..."the inlet passages had originally been of 1 +1/8" bore, but these had been sleeved down by the makers to the lower figure to aid midrange power and Syd Lawton for one found that competitors who tried to run with the sleeves removed and marginally larger 1+1/8 carbs were not as fast as his bike with the standard head"Is the Concentric really more efficient? It's cheaper to make, but the bore on full throttle isn't a clean tube like the Mono-bloc. But maybe the rough interior (under the slide) is better for fuel atomisation?The sleeve isn't as well supported so it's more sensitive to wear. By the time the Concentrics were added to 650 it must have been because of cost, availability, and the Commando was just round the corner anyway.

Well I have Steve Wilson's Book And The information in there is Not at accurate he is talking hear about racing and in racing the carburettors used back then would of been GP carbs , and Mono-bloc Carburettors are better in some ways, than the Concentric Carburettors that replaced them and Concentric carburettors did not com out till after 1965 ,So concentric carburettors where never fitted to the Manxman 650 or early Atlas. Now the Atlas was First Built On 20th April 1962 and all for export only, And as for handle bars are all down to the persons choice , but the standard 8 inch rise fitted by Norton are not as bad has you may think , and alot better that the 12 inch high bars on the later to come High rider Commando , and then you have H&D motorcycles with high bar as much as 21 inch hight now these are ape hangers and I have seen some even higher but they look rediculas , but so do some of the clip on handle bars there you are,

yours anna j

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Then as now there were various racing formulae...so you can't say they'd all use one carb.At very high revs no doubt the larger tract would work better. But the fact remains that Norton DID sleeve the inlets down on the bikessold on the high street and Steve Wilson's explanation is perfectly reasonable and therefore probably true. The optimum inlet size for a GP carb is a different issue. Very likely it is bigger and most likely Nortons made them oversize to improve the racing results but sleeved them to be better where flexibility was more important. .. which is nearly everywhere in the real world.
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Previously David Cooper wrote:

Then as now there were various racing formulae...so you can't say they'd all use one carb. At very high revs no doubt the larger tract would work better. But the fact remains that Norton DID sleeve the inlets down on the bikessold on the high street and Steve Wilson's explanation is perfectly reasonable and therefore probably true. The optimum inlet size for a GP carb is a different issue. Very likely it is bigger and most likely Nortons made them oversize to improve the racing results but sleeved them to be better where flexibility was more important. .. which is nearly everywhere in the real world.

From what I have read, both the Manxman and the 650SS were far from production racers. They were pleasant enough road bikes. The production racers were being built by Paul Dunstall and that is why he had to sell a quota of homologation models to the general public. I don't know the word for racers that are not production (maybe "works racers") but those were the bikes built by Doug Hele and I am sure they were not pleasant road bikes. Probably the horsepower figures for these racers was far higher than the Manxman or 650SS but approaching these high figures does not make one model "better". If the casting numbers are all the same, surely a good machanic can turn one into the other. And a better mechanic can build the ideal motorcycle for his or her own needs regardless of designation. If it is not a legendary model, why should he/she care? Oh, right, the resale value.

JS

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Previously David Cooper wrote:

Then as now there were various racing formulae...so you can't say they'd all use one carb. At very high revs no doubt the larger tract would work better. But the fact remains that Norton DID sleeve the inlets down on the bikessold on the high street and Steve Wilson's explanation is perfectly reasonable and therefore probably true. The optimum inlet size for a GP carb is a different issue. Very likely it is bigger and most likely Nortons made them oversize to improve the racing results but sleeved them to be better where flexibility was more important. .. which is nearly everywhere in the real world.
I would agree with the above. The SS head was used on the 500cc engines (88SS) which would probably have struggled with carbs above 1&1/16". Whether the sleeves were an after thought is a 'chicken & egg' question. The answer is in the Factory drawings which the NOC appear to have given away. Other anomalies which may or may not have been down to trial and error are siamesed pipes working well on some engines and not on others. Wasted pipes ( as found on Commandos) also work well on an Atlas but you do not see them on the smaller engines.
I would have thought that as part of engine development gas flows through both the carbs and exhausts would have taken place. Who knows? When I spoke to John Hudson about the 'devolopment' section of the Factory he said that there were generally never more than 3 people ever working at any one time on development.
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"The answer is in the Factory drawings which the NOC appear to have given away"

Phil, Is this true ? and if so, to whom ?

I was one of the group who visited Joe Francis Motors to assess those drawings and I was convinced that they would be a major asset to the Club. That is indeed why those of us who were there recommended their purchase so strongly, even though we knew that the production tools would never be useful for small volume production.

I have followed NOC affairs attentively ever since and am shocked to hear that such a disposal could have taken place without appearing in AGM or Treasurer's summaries.

Still, at least we're good chums with the new factory. These old bikes are not really very interesting.

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These old bikes will always be interesting as they bring back memories for people. That's the only reason for discussions such as these -basically the Manxman or 650SS were pleasant road bikes as Jonathan says and different people have different memories of them. Technically of course they are now out of date. It's hard to believe that the legendary 650SS, a superbike when I was young(ish) and impressionable has so little horsepower by modern standards. Of course the Norton twins had strong torque and for ordinary road use this means they are still quite useable on back roads - But they cannot compete with the current superbikes with 200 bhp except for one Manxman in East Yorks.

So the minor differences in models are not really important but at the same time it's these insignificant details which remind people of their past. It is a shame if records have gone missing.

Patrick.

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Previously patrick_mullen wrote:

These old bikes will always be interesting as they bring back memories for people. That's the only reason for discussions such as these -basically the Manxman or 650SS were pleasant road bikes as Jonathan says and different people have different memories of them. Technically of course they are now out of date. It's hard to believe that the legendary 650SS, a superbike when I was young(ish) and impressionable has so little horsepower by modern standards. Of course the Norton twins had strong torque and for ordinary road use this means they are still quite usable on back roads - But they cannot compete with the current superbikes with 200 bhp except for one Manxman in East York's.

So the minor differences in models are not really important but at the same time it's these insignificant details which remind people of their past. It is a shame if records have gone missing.

Patrick.

Well I would not call them minor differences when you have try get hold of the right parts , witch now are getting harder to find You just try getting a pair of Barrels for a kick off , I been looking for a pair for well over a year now, and nothing as come to light yet, and try getting a pair of Manxman Silencers there are next to impossible to get hold of at any price, then there try buy a Norton Manxman in this country if you can find one, Now As for The Technical Drawings I can tell you there in the Hands of Peter Holland , and You or I cannot get our hands on any of them nor can we even see them, I have brought this up a number of time with The NOC Chairman Tim Harrison , But Nothing has been done about it, These Technical drawing need taking to Donington Hall for safe keeping as part of a National Norton owners club Archive so all members can see them if they wish on prior appointment is made, with the NOC records officer , or librarian , these documents belong to the Members of the Club and Not one man , its You member need to make these changes , and lobby the NOC EC about its , And lets all try too make a difference , I am trying too do my part by doing this research on the 650cc models and this Book I am doing is for you all too give the owners of these motorcycles some accurate information , and Phil Hannan and myself, are trying out best on our own, if more member got involved the better it would be to put the right peace's of information to gether , As all Norton History need compiling To gether for the future generations to come, before its all lost in the mists of time, and every Norton motorcycle regardless of what it looked like is a part of the History of the Norton Mark so please help to save our history and our Heritage , Yours Anna J Dixon Founder of the East Yorkshire Branch , Technical officer for the branch,

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Like so many forums on the Internet, the one on the Norton Owners Club is turning into a mess of personal and derogatory commentary.

We need to understand and appreciate that there are thousands of Nortoneers on here with varying levels of skill, expertise and knowledge. But also remind ourselves that this forum serves as a way to attract potential members to the owners club and to buying a classic Norton.

New members may be younger, with different ideas but these people are the future of the owners club.

 


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