Wednesday, 17 October 2018

1930 DT Norton


Three photos of the Triumph/Norton as found. There were a couple of wheels with it in a similar sorry state!

-SG-  Another DT Norton engine – regrettably somewhat altered from its original specification – has come to light in New Zealand. This unit originally started life in a complete machine shipped to NZ in the Autumn of 1930 and finished up fitted to a real ‘Bitza.’ One could almost stretch a point and say that it was a ‘Triton’ as it comprised a 1929 Triumph frame and forks, and 1929 Sturmey gearbox as fitted only to certain Ariels in 1929/30. It had apparently languished in a damp cellar for many years before being bought by Alain.


Five general photos of the engine before dismantling, after a soak in diesel for several weeks.

Alain kindly brought the engine for me to have a look at earlier this year and we succeeded in partially dismantling it. Final dismantling took place a few weeks later, thanks to the loan by Viktor of his timing pinion puller.

Apart from the fact that the original timing cover had been replaced with an earlier ES2 cover the engine looked fairly original externally, with only minor repairable damage to the lugs at the bottom of the crankcase.


Various shots of the engine taken during dis-assembly.  Note bob-weight polished flywheels, long holding down studs for head and barrel, flange mounting for carb., twin exhaust ports with internal threads, large spigot on upper face of barrel and corresponding recess in head, piston crown with unrecognised markings.

The flywheels fitted are polished and of the bob-weight type, which came as a surprise. This is because the only other DT engine of which I have seen the internals has flywheels without bob-weights – more like those fitted to ES2s of the period but with 22mm mainshafts both sides. However, those fitted to this engine are assuredly of 1930 type and have a drilled timing side mainshaft for positive big end feed, Perhaps, therefore, both types were fitted to the production DT range but until we can find out about the internals of some of the other few survivors, it remains a matter of query.


Cam gear showing earlier (W7) cams and spacers to achieve alignment with followers.

Another difference on this engine which I feel probably dates from when it was built into the road bike, is that the original small base circle cams have been replaced with a pair of pre-1930 cams. These have been fitted with small steel bushes on either side of the spindles to ensure they are correctly aligned to operate the seemingly standard 1930 type cam followers.

Both head and barrel look in excellent condition – the head having twin exhaust ports with internal threads for exhaust pipe nuts as pictured on previous postings. And finally, the piston, lightly domed and with three compression rings, has numerous letters and figures stamped on it, none of which I recognise!

Friday, 12 October 2018

Maintenance Instructions 1926


-SG- As mentioned earlier, we have the 1925 Maintenance Instructions on the site already so the next one is that issued in 1926 - now attached - thanks again to Ian for the loan.

Tuesday, 9 October 2018

CS1 Cheffins Cambridge auction 20th Oct - lot 1226


-SG- Alan has drawn my attention to this 1928 CS1 sale - really looks a tidy restoration with only a few minor variations from standard and with a price guide of £18-20,000. The frame and engine numbers appear to be correct and matching BUT are they?  The Buff Logbook shows a CS prefix on the frame number which is wrong and more to the point - in my view - the frame number is stamped on the headstock. (Can't see if it has the same CS prefix on it.) In my experience, CS1 and ES2 frame numbers at the time were stamped on the lower front engine mount lug. I may be wrong of course and I accept there are exceptions to every rule but does this bike have a frame from another CS1/ES2 which has been re-numbered when the restoration was taking place?

PS; Robert has been in touch about frame number positions - see his message below. My own experiences don't conform to his views but this does not mean they are wrong!  Can we ask anyone with an EARLY CS1 or ES2 (ie late '27 or VERY early '28) to send us a quick message advising where their frame number is situated?  Incidentally, the CS1 I owned for a while dated from March 1928 and the number was down on the front engine mount lug.

"Robert: I have seen a very early 1928 CS1 frame with the number stamped in a similar fashion to that seen on the Cheffyns one. It did not have any letters and just had number stamps. For the very early frames, the number stamps appeared to be the same as those used on the engines.....At some stage the number migrated down to the front engine mount casting - probably later in the 1928 season, before moving back up again around 1930/1."

Saturday, 6 October 2018

The Beecroft bike!

Beecroft and the CS1, probably in 1958

-SG- The late Ron Beecroft's 1929 CS1 has appeared on the website before. In Ron's hands, it was a force to be reckoned with in Vintage sprints and is probably best known for an over 90 mph terminal speed at Brighton Speed Trials in the early fifties. Getting on for seventeen years back now, the bike and a spare engine (actually Ron's tuned sprint power unit) were sold through Verralls and the new owners in due course disposed of the sprint engine and built up the bike into a basically touring 1929 model . This, in turn, has changed hands a couple of times and the new owner, Neil, has recently been in touch.  He reports that the file of documents he received with the bike shows Ron seemingly acquired the bike in 1948 or thereabouts but did not tax it for road use after 1950.  Included in the file were a couple of excerpts from the VMCC Bulletin (this was before the days of the actual Magazine!)  and the texts - one being a brief write-up by Titch Allen from 1948 and the other Ron's tuning notes from 1951 - are below.  Thanks Neil!


BEECROFT CS1 TUNING NOTES 1951 VMCC BULLETIN

A “cammy” owner usually has already some experience of motorcycles. If he is more or less a “First Year Man,” it would be wiser to start with some other type but, perhaps, not a two-stroke. There are on sale good handbooks on “Tuning for Speed;” the home tuner will find one of these of immense help as they are written by competent authors.

These notes, then, must only be regarded as a possible help to those liable to make, in the future, the mistakes the writer has committed in the past. Using ordinary handwork tools, most jobs can be managed if care, patience and cleanliness are used, except possibly the task of lining-up flywheels.

The choice of event one intends entering governs the machine’s preparation and for sprints and short distance work generally, especially when transport for the bike can be used, an alcohol fuel and stripped racing trim will be the set-up for success. The engine will have to be fitted with a new piston, giving a compression ratio of at least 10 to 1 and other work carried out, if the most is to be gained from the potentially greatly increased power over that with a standard motor on petrol. This work is to make quite sure of the reliability for, to resort to history, the CS1 power unit of 1927 to 1930 was designed in the NORTON tradition by Walter Moore (who is also notable for introducing the pivot-mounted gearbox, patented in 1925.) It was designed as a petrol-benzole engine and “swept the board” for a period in the ‘Island’ and elsewhere before being completely redesigned at the close of 1930.

It is not too hard to guess that there were reasons for this alteration. One finds them first hand.

Work on the Engine

The vertical-shaft bearings and main bearings must be in sound condition if the bevels are to endure. This may mean new bearings, but I have simply fitted new 9/32” balls into the self aligning – Hoffman races where they are not too badly worn or pitted. The crankshaft and flywheels must not have endfloat that can be noticed when the crankcase is bolted up, or the depth or MESH of the “bottom bevels” will be affected. These bevels must engage deeply; they are only too anxious to come out of mesh and destroy themselves and most of the engine too, if care to get this part right is not taken. If the adjustment to get the flywheels central in the crankcase has been done by a number of shims on the drive side mainshaft, it is safer to remove them, measure their combined thickness and get or make a shim or shims, to go behind the drive side main race, which will have to be removed from its housing – unshrunk – for this shim, which can be of ordinary steel, to be inserted. Nothing must be left that might vary the mesh of gear teeth under load. Engine bolts holding the crankcase halves together must be good.

The 1927 engines had no dowels at the back of the cage or housing of the lower vertical bevel. If yours is one of these, a single dowel or even projecting screw locating in the crankcase wall will pay dividends. Those engines suffer from fractured guide cages to the oil pump plunger pin. The pin fits snugly between the bronze faces, if not, the pin is worn or a guide from a 1928 or later model is needed (later plunger guides being much sturdier.) The oil pump is not brilliant and needs full motion and unrestricted passages. While the engine is down it will help if the port joining the bevel-panel with the trough below the flywheels is filed, and cleaned up, also a larger return oil pipe to the tank is worthwhile. The standard arrangement for holding the cylinder head down fails under the high gas pressures of dope and H/C ratios. The studs should be removed and replaced by a set of the later kind that screw directly into the crankcase for this fuel.

If alcohol ratios are used, the con-rod, with ⅝” piston pin is doubtful, and cracked gudgeon bosses can be anticipated. A rod with ⅞” small-end is desirable. Keep the original cams and timing. Strong valve springs are unnecessary, and likely to offset any gain in performance at high r.p.m. by causing flexing of the rocker-box platform, reducing valve lift and increasing stress on O.H.C. gear generally. Modern valve spring collars are too heavy and may rub against the cambox endplate. Valves and guides for the current NORTON ES2 models are very slightly larger in the head and body diameter respectively and make useful replacements, but something seems wrong with the steels when used as an exhaust valve, and the writer uses old tulip valves.

Semi-dry Sump Oiling System

Much could be written on this but it will suffice here to state that for sprints turn the metering tap full on and the sump level adjust to lowest number. Longer events, put level adjuster at “high.” Castrol “R” is recommended, or any event on Dope, but used methanol for touring and experimenting during petrol “black out” on a 13 to 1 C/R with mineral oil. Be sure the oil pump driving worm is screwed (L.H. thread) tightly home as it has been known to break through the timing cover panel during a backfire!

Carburettor

The original Binks gives results!

Magneto

Guard against too much advance, ⅝” B.T.D.C. is ample with petrol mixtures. A KLG M.80 Plug (5/-) works well.

General

There is little to object in polishing the insides of the motor if your clutch is going to slip in the race, or the oil delivery pipe comes detached. Attention to details of the bicycle parts seems to be even more necessary on vintage jobs now they have reached their majority.


“CAMMY” NORTON The 1928 CS1 Norton of R A Beecroft
Written by Titch Allen 1948

“I said before that machines reflect the personality of their owners, and so does this Norton. Once again a preconceived notion was knocked sideways, for this Norton, though a fast road gobbling hog bus is smooth, delightfully smooth, in the sense that a Longstroke Sunbeam is smooth. But this is the iron hand in the silk glove ... open up the throttle and there is punch with an edge to it that can be felt through the smoothness and hedgerows begin to stream by in that way that bespeaks of the sixties. It is not a machine to test in a garden suburb; it needs arterials ... a long winding ribbon of road stretched across a broad countryside, so that the half gallon of oil in circulation gets warm and in the retention of tune, one can find the advantage of the O.H.C. instead of the O.H.V. design. Beecroft is of course a watchmaker ... somehow he has introduced something of the precision of his craft into that engine. There is always the feeling of large wheels spinning as if motionless between perfect centres ... never that of a constant struggle between rotation and reciprocation. Though not suited to my stature, the riding position tempts one to emulate Stanley Woods – the handling is good and the brakes excellent.”

Thursday, 4 October 2018

The FIRST OHV Norton ...


-SG- ... was seemingly built in 1919 but not by the factory! It was the brain-child of a Welsh enthusiast Charles Sgonina, who rode it to good effect in the 1919 Weston-super-Mare speed trials and elsewhere. He had carried out his modifications to a Model 9 and brief details are given in the report of the event in 'The Motor Cycle' of 4th September, which also includes a timing side photo.  Sgonina is well known in UK motorcycling history as he went on to build both single and double OHC power units, also Norton based, in the early twenties. The scans attached cover the event referred to above, and the DOHC Sgonina Special in its final form (note - it had a Sunbeam gearbox).  I might add that since the 1955 photos, it has, I am told, been 'tastefully' restored! Many thanks to Martin  for drawing our attention to this and sending the 1919 scans.



Roger has kindly generated a much clearer image of the 1919 Sgonina-modified Norton engine and this is provided along with a CAD model.  He has established that Sgonina lowered the engine in the frame by about an inch in order to provide clearance for the rockers.

Monday, 1 October 2018

Parts for CS1 and ES2 (and Models 30, 40 and CJ) subsequent to 1931


-SG- One of the parts lists we can now add to the Library - many thanks as usual to Ian - is that covering CS1 and ES2 models subsequent to 1931. Note that page one suggests that the list can also be used to order spares for Model 30, 40 and CJ. Worth mentioning that the Model 22 no longer appears in the list and also that the three speed gearbox illustrated is the LS type rather than the Type III which I think had come into use during 1931 - if the despatch book records are to be believed.

Sunday, 30 September 2018

Model 21 at Schalleberg Classic


-JdK- Markus sent us a note and pics: "Meanwhile, with the help of the forum, I found all missing parts for my racing bike and was able to provide the project in time for the Schallenberg Classic mountain race. The Norton is a Model 21, frame no. 264XX and engine no. 333XX, dispatched from factory to Demont in Switzerland on 17th January 1927. It was never important to me that the Norton is built 100% original. It should be a racing bike, which is also needed for this. For the race, I took my second Norton, a 1926 Model 18 with street trim, it was a crowd puller. Unfortunately, it did not go without problems. 


Before the first run on Saturday, the front fork column broke, luckily only at walking pace. Unthinkable if that happened at high speed! Upon close inspection, the column was soldered sometime before as seen on pictures. I did not realize this modification as it was not visible. The problem could still be solved on place by many helpers and on Sunday I could participate in the race. Even though I did not win a cup, my first mountain race with the Norton was a wonderful experience. More races will follow next year!"

Thursday, 27 September 2018

Rem Fowler's silver hip flask ...


-SG- ... is for auction on 13 October, by Bonhams at Stafford.  It was presented to him for the best performance in 1907 by any member of the Birmingham Motor Cycle Club, for winning the Twin Cylinder class in the inaugural TT. Included is a folder of period press cuttings, photos etc as well as letters between Rem and J L Norton, Harold Karslake and John Griffith (see also posting of 27 October 2011).  Guide price is ... wait for it ... £20,000 to £30,000!  Seems a lot of money when silver flasks of this type and age can be had for under £500 ...

Wednesday, 26 September 2018

When is a Norton not a Norton ...


-SG- ... when it's 'Bluey!' Bluey was the nick-name of the special built in the mid thirties by Josh Mewhinney down in Otago in the south of New Zealand. It comprised a 1930 DT Norton frame and forks and a very special Indian vee twin Altoona engine dating from 1925. It had considerable success in hill climb and grass events with at least two different riders and most of the engine still exists, albeit with different heads and barrels. However, what became of the DT Norton frame is unknown ...

The photos show it in action at Bethunes Gully Hill Climb (near Dunedin) in 1947 and in the pits at another un-named event. It is thought that it was not used much later than 1948/9. Thanks to Bill and Alain for the photos.

Monday, 24 September 2018

Cannonball Nortons !


-JdK- Keith just contacted us to inform his team just finished the Motorcycle Cannonball. "The 1924 and 1923 Model 16H Nortons made all the miles and both finished with a perfect score. The 1915 bike missed 11 miles when the tappet block threads stripped in the engine case. We rode 3500 miles in 15 days through some of the finest roads in the USA. The photo shows the bikes in Glacier National Park."