Misc: Everything Else Comet: primary chain oil leaking out mainshaft hole behind clutch

vibrac

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VOC Member
I am sure on some long gone British single( Ariel VH?) or even a BSA (god forbid!) there was a sliding shutter arrangement made of a tin plate with an oval hole riveted to the back of the chaincase with a bent up groove formed along the top and bottom and a sliding shutter with a shaft hole in it, very neat. I guess the bean counters stopped any sophistication like that in 1950 Stevenage
 

Nulli Secundus

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VOC Forum Moderator
I am sure on some long gone British single( Ariel VH?) or even a BSA (god forbid!) there was a sliding shutter arrangement made of a tin plate with an oval hole riveted to the back of the chaincase with a bent up groove formed along the top and bottom and a sliding shutter with a shaft hole in it, very neat. I guess the bean counters stopped any sophistication like that in 1950 Stevenage
The Norton Commando has something along the lines of that description and it seems to work.
 

Chris Launders

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VOC Member
This is the BSA A10 one, you could make your own version with a proper seal in the middle, the felt goes BEHIND the plate to stop leaks between the plate and case.
1602833289584.png
 

Marcus Bowden

VOC Hon. Overseas Representative
VOC Member
This is what Pat Wilson did in 1952 or 53 when building the trials Grey Flash (the only one) with the chain-driven timing side and sounds like a Velo so he told me I've had it since about 1975 but iit's coming together slowly with a lot of pushing from Vibrac.
BANANAMAN.

SHAFT SIZE HOLE IN SLIDING PLATE WITH RIVETED IN GUIDE PLATES
DSCF0883.jpg
 

b'knighted

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VOC Member
A good picture Marcus.
It also shows the relationship between the heights of the drain plug and the level plug showing that the intention was to have a dribble of oil for the bottom of the chain to run in.
Is there really such a problem when the oil is at the correct level?
 

vibrac

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A good picture Marcus.
It also shows the relationship between the heights of the drain plug and the level plug showing that the intention was to have a dribble of oil for the bottom of the chain to run in.
Is there really such a problem when the oil is at the correct level?
No but the Chain cam could be at 45 degrees from vertical (in either plane!) on a Trials section and you dont want oil on your trials tyre
 

ericg

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Similar set up on Pre unit Triumphs.
I suspect all British made machines with non unit engine-gearbox used a sliding disc to seal the chain case. Except Vincent apparently?
 

Sakura

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Non-VOC Member
I am sure on some long gone British single( Ariel VH?) or even a BSA (god forbid!) there was a sliding shutter arrangement made of a tin plate with an oval hole riveted to the back of the chaincase with a bent up groove formed along the top and bottom and a sliding shutter with a shaft hole in it, very neat. I guess the bean counters stopped any sophistication like that in 1950 Stevenage
Why disparage BSA, undoubtedly the most successful motorcycle engineering company ever in the UK? Not only bikes but cars, machine tools, steels, mining equipment, arms, bicycles etc.
 
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