Conway Anti-Sumping Valve A65V

[Michel]

Hello everybody,
On my Comet Serie A, the anti sumping-valve from Conway broke down after just two years. I avoided the worst by reacting immediately and stop the engine.
Have you had the same adventure ? Do you still trust this valve that I am thinking of replacing ?
Greating from Provence.

 

[Peter Holmes]

I did purchase one years ago from Colin Jenner, but I never had the courage to install it, it just seemed wrong to ask of the pump to pull or push it open, whatever it does, I was happy with the light spring to shut it of though, I just prefer to drain off the sump if the bike has stood for a while, when you are risking paying thousands of whatever currency you use, and trying to find someone capable of rebuilding a wrecked engine, it is just not worth the risk for me.

 

[vibrac]

A non -return valve is not for me!
Its not a big faff to drain the sump in the spring and as far as the Comet is concerned just pulling it back on compression if it is going to stand for a week or more (memories of the grid in the days of bump start)
My Velo KSS Mk1 is a bit of an oozer (Castrol R of course!) I have fitted a tap on the oil tank with a curley whorley string to a hole in the front brake lever even I cant miss that on the high days and holidays I use it.

 

[Simon Dinsdale]

Don't forget everyone, Michel's bike is a series A Comet which has a gear type oil pump which produces a lot more flow / pressure that the later series B. c etc, but because its a gear type oil pump it will dump the whole contents of the oil tank into the engine within 10 days which is no different to Nortons, Velo's and other manufacturers that used gear type oil pumps. It wasn't a problem when the bikes were used every day.

 

[nkt267]

Don't forget everyone, Michel's bike is a series A Comet which has a gear type oil pump which produces a lot more flow / pressure that the later series B. c etc, but because its a gear type oil pump it will dump the whole contents of the oil tank into the engine within 10 days which is no different to Nortons, Velo's and other manufacturers that used gear type oil pumps. It wasn't a problem when the bikes were used every day.

Same with my 1932 Sunbeam - 4 days to empty the tank

 

[vibrac]

Simons comments gives me a piece of logic to back up and explain my comments in #3

 

[ericg]

I have such a valve on my Commando for the last 31 years and about 40 000 miles same on my Norvin 12 years and about 28 000 miles.
No problem so far so I have fitted one on my latest project which is a Comet engined special.
What does fails on your valve Michel? And how did you know that there was a problem?

 

[Peter Holmes]

Far be it for me to answer on someone else's behalf, but generally speaking, a lack of oil equals seizure, if you are lucky you will notice a lack of power first, you need to catch it very quickly to avoid serious and expensive damage.

 

[Gary Gittleson]

Seems to me an anti-sumping valve introduces a perhaps not-very-likely risk with serious consequences to solve a minor inconvenience. I'll deal with latter. It was never a problem with my Norton Atlas (which I sold years go but rode for some 40,000 miles) and no bother at all with the Rapide.

 

[Marcus Bowden]

Here is what I did for riding "Old Harry" No fuel no going any where so link fuel to Oil cock. Petrol when lever is horizontal and oil off, when down petrol on with oil.
Butterfly knob forward of exhaust valve spring is flexible adjuster for pilot screw and butterfly hanging over link rod is adjuster for throttle stop for slide. and can all be adjusted with gloved hand and the same for all my bikes. Practical solutions for easiness and not having to dismount to get tools. have actually done the same on my "B" Rapide as not used so much nowadays. Can take a photo if anyone wants it.
bananaman.