Just read this in a Triton advert on Evilbay!
"The Norton vertical twin engines had a reliability problem when tuned. At about 7000rpm the piston exceeded the engineering limit for piston speed, so over-revving soon destroyed the engines."
EBay item 263180918130
Any thoughts on this?
Cheers
John H
John, in the modern age th…
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Were the Norton Factory ra…
Were the Norton Factory race engines etc not successfully tuned?
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How could he get it so wro…
How could he get it so wrong? It's the con rods that let go.
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For what i is worth: Max.…
For what i is worth:
Max. piston speed at 7000 rpm,
650SS 32.62 ms-1, 99SS 30.05 ms-1, 88SS 26.61 ms-1.
T110,30.05 ms-1, T100 29.32 ms-1.
BHP 650SS 49@6800, 99SS 44@6750, 88SS 36@ 7000
T110 40@6500, T100 32@6500.
Values of about 40 ms-1 are usual safe upper limits for air cooled motorbike engines.
Safe limit in rpm dependson piston weight, con rod strength, valve train acceleration etc.
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C'mon Chaps, play ball. L…
C'mon Chaps, play ball.
Let's have it in IMPERIAL!ow this is where the Short-stroke/Long-stroke dilemma starts to take place, with piston speed, acceleration deceleration forces.
Someone once told me once you go above 4,500fpm, then it's usually curtains, not sure about new engines though.
Anyhow in imperial it's:
4087.9265091863513, feet per minute; 650SS @7,000rpm;
3766.4041994750655,fpm, 99SS
2.858267716535433,fpm 88SS
*3766.4041994750655,fpm T110.
A Eureka Moment?
Now look at that the Triumph T110 a 649cc engine is only doing the same fpm as the 497cc 88SS! Was that because they were a more fragile engine, or did Triumph engineers know something Norton engineers didn't?
Cheers
John H
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Previously john_hall1 wrot…
Previously john_hall1 wrote:
C'mon Chaps, play ball.
Let's have it in IMPERIAL!ow this is where the Short-stroke/Long-stroke dilemma starts to take place, with piston speed, acceleration deceleration forces.
Someone once told me once you go above 4,500fpm, then it's usually curtains, not sure about new engines though.
Anyhow in imperial it's:
4087.9265091863513, feet per minute; 650SS @7,000rpm;
3766.4041994750655,fpm, 99SS
2.858267716535433,fpm 88SS
*3766.4041994750655,fpm T110.
A Eureka Moment?
Now look at that the Triumph T110 a 649cc engine is only doing the same fpm as the 497cc 88SS! Was that because they were a more fragile engine, or did Triumph engineers know something Norton engineers didn't?
Cheers
John H
Shorter stroke=lower piston speed for a given rpm
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T110 has 82mm stroke. Mean…
T110 has 82mm stroke. Mean piston speed at 7000rpm = 3766 ft/min
88 has 72.6 stroke. Mean piston speed = 3335 ft/min.
99 has 82mm same 3766 piston speed as T110
650 has 89mm. Mean speed at 7000rpm = 4088 ft/min
I seem to recall that up to 4500 was generally considered OK for piston speed. Beyond some number close to that, the bore lubrication starts to fail. So all these machines are OK in respect of piston speed.
Thetension forces in the con rod are proportional to the stroke and the piston mass. So at 7000rpm (if the pistons weigh the same - which they do not - quite) the 650 con rod has 25% more stress than the 88. A heavier piston increases that stress a bit more, and small changes in stress cause much bigger changes in fatigue life.
Alloy rods don't sound a brilliant idea - but not nearly as much was known about fatigue in 1949 as it is now so (just possibly) that has some relevance. Steel has about three times that fatigue life of aluminium alloys when it has the same stress - but sadly it is also three times heavier.
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Thanks Charles, guess most…
Thanks Charles, guess most of us would work that out, stroke equalling distance, but there are of course other forces involved and power output isn't linear to RPM as far as efficiency is concerned.
http://www.csgnetwork.com/pistonspeedcalc.html
I suppose if the natural cruising speed of the engine is lower down the fpm calculations there are less stresses all round on the engine the longer it may last.
My Imp engine with a stroke of 60.37mm would have to rev to 10,250rpm to get anywhere near the Norton 650SS @ 7.000rpm, this would give it 4060.3182414698153 fpm!
The nice link is that Leo Kuzmicki worked on the Imp engine for Rootes and he was the fellow who made the last developments for a power increase from the Manx Norton cylinder head for Joe Craig in the Late 40s . At that time Geoff Duke was involved and knew that was all that could be done for the Manx DOHC engines, it was he who made the last great push to replace the single cylinder race engine with a multi-cylinder option.
Gilera had their 4 from 1935/6!
They even put a Sunbeam S7 engine in a Feather-bed frame!
Cheers
John H
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"They" being ? And did the…
"They" being ? And did they also use the S7 gearbox/transmission?
It sees like a very complicated way to make a 500 with even less performance than an ES2 (I've owned both, though not at the same time).
Previously john_hall1 wrote:
...
They even put a Sunbeam S7 engine in a Feather-bed frame!
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Just out of interest (to a…
Just out of interest (to any "singles" guys reading this thread) the ES2 at 5300 rpm gives a mean piston speed of 3478ft/min so well within the 4500ft/min limit. Conversely a max of 6860 rpm at max piston speed? Anyway, sounds like a well under-stressed engine. George
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Previously Julian Wells wr…
Previously Julian Wells wrote:
"They" being ? And did they also use the S7 gearbox/transmission?
It sees like a very complicated way to make a 500 with even less performance than an ES2 (I've owned both, though not at the same time).
Previously john_hall1 wrote:
...
They even put a Sunbeam S7 engine in an "adapted"* Feather-bed frame!
"They", being; Rex McCandless, Leo Kuzmicki, Charlie Edwards, tested by Geoff Duke who was pole-vaulted off eventually at Mira, as the special work by Kuzmicki on the engine, put 39bhp running on methanol, through the transmission which eventually broke and hit the tarmac resulting in Geoff Duke flying through the air!
"They", were desperate for a Multi-cylinder race bike to challenge the Italian and German threat, Joe Craig had been at AMC before he rejoined Norton after the war and had worked on the rival firms Plumstead Porcupine, during the War years. Some think the difficulties they, (AJS/Matchless) experienced, (and of course it was initially designed for Supercharging) had put him off Muti-cylinder plots!
Page 46,"To make a Better Mousetrap", R.L.Jennings, Biography of Rex McCandless with a picture too of the S7 engined Feather-bed motorcycle!
The book is written by an Irishman, employed as a Draughtsman about mainly other "Ulstermen", Cromie Mc Candless, Artie Bell, Oliver Nelson, Joe Craig, (Himself)! Ernie Lyons from across the border, Freddie Dixon, Rex's mentor; who were there at this time in his life, either in Belfast or with Norton in England or personal friends!
The motorcycle section is set during the 6 year period that Rex McCandless spent working as a Specialist Engineer attached to, but not directly employed by Norton Motors.
ISBN: 9780953462841
Cheers
John H
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Previously john_hall1 wrot…
Previously john_hall1 wrote:
Just read this in a Triton advert on Evilbay!
"The Norton vertical twin engines had a reliability problem when tuned. At about 7000rpm the piston exceeded the engineering limit for piston speed, so over-revving soon destroyed the engines."
EBay item 263180918130
Any thoughts on this?
Cheers
John H
Hello John There trying to say that they have a case to say that the Triumphengine is better than your Norton Engine when in a Tuned State Well In my younger days I Raced Nortons and rode As passenger ON sidecars Ans in my time I have seen more blown Triumph engines then Norton ones So has Neil Says total BS The Triumphengine has only one good thing going for it And that'sthe availability of Cheap and plentiful of Spares as Triumphknocked out 130 bikes to one Norton, If methodical care of race prepared Norton Engine you have a ten time better engine that a Triumph twins for one the Norton engine is designed to cool better than a Triumphtwin . is funny that Sidecar builders useda BSA A65 with a Norton Atlas Crank and a Devimeadtop end making a 903cc race engine and these were fast to in their day But our team used an imp engine which had some problems with throttle openings, In the End, our team when two-strokewith an 800cc flat four Konig Tuned to 130 bhp now it could shift and my arse was next to the road on corners and Iusuallyended with bruisesall over for to hump and bumps in the roadsor race tracks, I have had some very close shaves and next to being in a coffin, in my time but still here to tell the story, its a good job I was in my teens and early twenties at the time, but this was way back in the early nineteenseventies how time passes Now stay safe out there and have fun yours anna j
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Previously Julian Wells wr…
Previously Julian Wells wrote:
"They" being ? And did they also use the S7 gearbox/transmission?
It sees like a very complicated way to make a 500 with even less performance than an ES2 (I've owned both, though not at the same time).
Previously john_hall1 wrote:
...
They even put a Sunbeam S7 engine in a Feather-bed frame!
Well the first engine to be fitted in a Norton Featherbed Frame was a 600cc Fiat bolted to a Douglasgearbox and Rex Mc-Candelas raced this bike in the Northwest 200 and won , yours anna j
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Hello, Now When the first…
Hello, Now When the first 650 Manxman engine was tested on the dyno ,Doug Hele Ran them for well over there time limits at 9000 rpm to destruction but he found they were safe to run at 9000rpm for long periods of time, and all Norton engines were tested on the dyno before being fitted into its frame this is why we get shop number runningout of chronological order and the Manxman engine was the development from the 500cc racing engines known has the domiraces Doug Hele engineeringdevelopments the rest is now history
yours anna j
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Previously anna jeannette…
Previously anna jeannette Dixon wrote:
Previously Julian Wells wrote:
"They" being ? And did they also use the S7 gearbox/transmission?
It sees like a very complicated way to make a 500 with even less performance than an ES2 (I've owned both, though not at the same time).
Previously john_hall1 wrote:
...
They even put a Sunbeam S7 engine in a Feather-bed frame!
Well the first engine to be fitted in a Norton Featherbed Frame was a 600cc Fiat bolted to a Douglasgearbox and Rex Mc-Candelas raced this bike in the Northwest 200 and won , yours anna j
No he didn't, unless the records are wrong. The only Fiat engine of that size available was a 17 bhp sidevalve water cooled 4 from the Topolino. Had one years and years ago. would not have pulled the skin off of a rice pudding.
Artie Bell won on a Norton in 1947, 1949 and on a featherbed in 1950
No race in 1948.
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Previously anna jeannette…
Previously anna jeannette Dixon wrote:
Previously Julian Wells wrote:
"They" being ? And did they also use the S7 gearbox/transmission?
It sees like a very complicated way to make a 500 with even less performance than an ES2 (I've owned both, though not at the same time).
Previously john_hall1 wrote:
...
They even put a Sunbeam S7 engine in a Feather-bed frame!
Well the first engine to be fitted in a Norton Featherbed Frame was a 600cc Fiat bolted to a Douglasgearbox and Rex Mc-Candelas raced this bike in the Northwest 200 and won , yours anna j
No he didn't, unless the records are wrong. The only Fiat engine of that size available was a 17 bhp sidevalve water cooled 4 from the Topolino. Had one years and years ago. would not have pulled the skin off of a rice pudding.
Artie Bell won on a Norton in 1947, 1949 and on a featherbed in 1950.
I doubt that one would dynotest manxman engines to 9000 rpm. The valve train design would not have allowed it.
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Yikes! 39 bhp through the…
Yikes! 39 bhp through the S7 shaft and worm-gear? I'm not surprised it broke.
I'll have to ask for the book as an Xmas present
Meanwhile, given the facilities available to the team, why didn't they abandon everything aft of where the crank exits the case, turn the engine through 90?, and use a Manx primary drive, gearbox, etc., of which there were presumably one or two lying around the works?
The S7/S8 engines have a robust crank (admittedly with only two main bearings), short stroke (70mm x 63.5mm, and an "improvable" OHC head, so a plausible candidate for tuning, given a more suitable (for competition) transmission.
Julian
Previously john_hall1 wrote:
Previously Julian Wells wrote:
"They" being ? And did they also use the S7 gearbox/transmission?
It sees like a very complicated way to make a 500 with even less performance than an ES2 (I've owned both, though not at the same time).
Previously john_hall1 wrote:
...
They even put a Sunbeam S7 engine in an "adapted"* Feather-bed frame!
"They", being; Rex McCandless, Leo Kuzmicki, Charlie Edwards, tested by Geoff Duke who was pole-vaulted off eventually at Mira, as the special work by Kuzmicki on the engine, put 39bhp running on methanol, through the transmission which eventually broke and hit the tarmac resulting in Geoff Duke flying through the air!
"They", were desperate for a Multi-cylinder race bike to challenge the Italian and German threat, Joe Craig had been at AMC before he rejoined Norton after the war and had worked on the rival firms Plumstead Porcupine, during the War years. Some think the difficulties they, (AJS/Matchless) experienced, (and of course it was initially designed for Supercharging) had put him off Muti-cylinder plots!
Page 46,"To make a Better Mousetrap", R.L.Jennings, Biography of Rex McCandless with a picture too of the S7 engined Feather-bed motorcycle!
The book is written by an Irishman, employed as a Draughtsman about mainly other "Ulstermen", Cromie Mc Candless, Artie Bell, Oliver Nelson, Joe Craig, (Himself)! Ernie Lyons from across the border, Freddie Dixon, Rex's mentor; who were there at this time in his life, either in Belfast or with Norton in England or personal friends!
The motorcycle section is set during the 6 year period that Rex McCandless spent working as a Specialist Engineer attached to, but not directly employed by Norton Motors.
ISBN: 9780953462841
Cheers
John H
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You get the book straight…
You get the book straight from the author in Belfast;
http://www.jenningspublishing.co.uk/
I wish there was more books like this, "straight from the horses mouth", so to speak!
The Sunbeam engine in "its all-aluminium, "unit-construction", single overhead-camshaft, horizontally split engine unit", is very similar to the Imp unit, bore and stroke dimensions are not too different too. My 930 Imp unit, has a 70mm bore and a 60.37 stroke, just under 3mm difference,
This forward looking engine design, influenced the Hillman Imp engine, when they finally adopted the production version final form, initially from the Coventry Climax FWMA engine unit. Of course BSA cocked-it all up by using unsuitable not robust enough under-slung worm drives acquired from some other company supplies. Bit like Norton using up the parts from the earlier tube and lug frame bins, when in reality nearly all their customers wanted feather-beds framed stuff!
Hindsight a wonderful thing!
Cheers
John H
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John, in the modern age the age of modern fuel (Needle sticking) we are fed on a regular diet of BS. It's up to the individual what to believe, at least until belief becomes heresy! Coming to a place near you soon!