Monday 26 June 2023

Use 'em! 1930s International Norton


-JdK- This is my 1930s International Norton, bought in September last year. I took the bike to B.O.M's Veteranen Tour in Belgium last weekend and as I hate to carry bikes on a trailer I rode the bike to Berlare, near Antwerp, did the tour on Saturday to Houffalize near Luxembourg and rode the bike back home near Utrecht on Sunday. All in all I did 585 miles - 940 km in three days without any issues. These pics were taken on Sunday evening and I did not clean the bike. Off course we've seen oil tight Nortons before but for a Carroll engined Norton this is pretty OK. Most of the oil it leaks now comes from a breather throwing oil in the magneto chain case and I guess it was designed to leak out this way as later Norton have a small tube in this chain case to drain excess oil. It runs on Castrol R40 bytheway.

What is it? The Norton came from the factory in 1933 as a Model 40. There's no mention of special tuning but it had no kickstart, racing footrests and racing chain guards and large tanks fitted. The engine currently fitted comes from a 1938 CS1 and has been in this frame at least since the 1960s according to the old green registration book. The girders are 1946, the gearbox late 1930s. Previous owners were James Gardner (1966), Henry Ormonde Gurr (1973, below) and Dennis Butler (1987). I think Butler had it sold by Andy Tiernan in 2021 to Dave who sold it to me in September last year.

There is a movie on YouTube (above) where Andy Tiernan talks about the bike and it's pretty funny. He remarks:  "it was used by someone who went to Scotland on it, cruising at 70 and seeing 80. The engine was done by a well known gentleman in the engine world connected to Ricardo, but can't remember his name. It was done to a very high standard". I like Andy, he probably means Ormonde Gurr who was known to work on Ricardo Triumphs but it sounds a bit silly. If anyone knows more about any of the previous owners (except for Dave off course) then let me know!

Dave liked the bike a lot and did 3000 miles on it in one year which to me suggested the bike should be in decent condition and it ran OK when it arrived. But as always I expect to find plenty wrong with a 90 year old bike and I therefore took it to bits and rebuilt most of it over the winter.

I thought it would be nice to list what needed doing:

The engine was partly disassembled. The crank was left in situ, mainly because the pinion is stuck on the crankpin and I did not feel like applying a lot of heat and using a big hammer. The big end and mains feel fine and everything inside the engine looks clean. The standard CS1 piston looks unworn but the rings were stuck in the grooves which were cleaned. The small end bush was scored and therefore replaced. The guides and valve stems have some wear but were cleaned and reused as were the springs. The cam box was cleaned and new rubber and cork seals fitted. I did not change the timing while this seems to be a mixture between Model 30 and CS1 timing; inlet opens 45 BTDC, closes 60 ABDC; exhaust opens 85 BBDC, closes early at 30 ATDC. Compare this to the tabulated data we compiled. Perhaps this was the genius of the well known gentleman and Ricardo.

The gearbox needed a few new bearings and a thrust washer

Both wheels needed new bearings and new brake drums. The old drums had been skimmed which sounds like a good idea but the downside is that all standard size shoes are too small now giving a very spongy feel to the brakes. New drums fixed the problem.

The girders were rebuilt using new spindles. The headlamp was fitted with new brackets to position it somewhat lower. The 22 mm handlebars were replaced by proper 1" bars which cured the vibration. Numerous holes were welded in the guards and new brackets fitted. Weird-threaded bolts and nuts replaced everywhere. The internals of the dynamo were thrown away and the lights replace by energy efficient LEDs. The magneto was rewound. All petrol and oil hoses replaced. New tires fitted. New brackets and springs fitted to the saddle. New petrol taps.

Not too bad and it was worth it, this has quickly become one of my favorite Nortons. Not sure if it will do 70-80 MPH in Scotland but it was very happy cruising at 55-60 MPH in the Ardennes yesterday.