Conways Anti Sumping Valve on Twin start pumps

minivin

Well Known and Active Forum User
VOC Member
Gents and Ladies,

Does anyone have any experience of running a twin start pump with a Conways Anti Sumping Valve? I notice on their website that they are "suitable for Series "A's" and all Post-War Vincents with Single Start Oil Pumps".

I have just tried to replace my pump in situ on the Comet and unfortunately found out that the oil pump drive gear is larger than the outer bearing race. No pump sleeve out, no new pump sleeve in.

Oh, and I sheared the camshaft spindle while trying to replace everything. Deep joy.....
 

ogrilp400

Well Known and Active Forum User
Non-VOC Member
G'day,
Why would the anti drain valve be a problem with a twin start oil pump scroll? Twin start just means that the ADV would be twice as likely to work, or or open in half the time.
 

Martyn Goodwin

Well Known and Active Forum User
Non-VOC Member
Gents and Ladies,

Does anyone have any experience of running a twin start pump with a Conways Anti Sumping Valve? I notice on their website that they are "suitable for Series "A's" and all Post-War Vincents with Single Start Oil Pumps".

I have just tried to replace my pump in situ on the Comet and unfortunately found out that the oil pump drive gear is larger than the outer bearing race. No pump sleeve out, no new pump sleeve in.

Oh, and I sheared the camshaft spindle while trying to replace everything. Deep joy.....

If your oil pump is in good condition you should have no need for an anti-sumping valve - for as I understand it you only get sumping if the oil pump is knackered. Remember, at any time around 1 cup of oil in the sump is normal.
 

minivin

Well Known and Active Forum User
VOC Member
Unfortunately after having a new pump fitted during the winter rebuild, so as to replace one that sumped slowly, I now have a new pump that sumps half the tank over a month. I don't fancy stripping the engine once again before the next winter, so a quick fix is better than loosing another summer.
 

minivin

Well Known and Active Forum User
VOC Member
G'day,
Why would the anti drain valve be a problem with a twin start oil pump scroll? Twin start just means that the ADV would be twice as likely to work, or or open in half the time.

This is my thoughts. I think a phone call to Colin is in order for this morning
 

Big Sid

Well Known and Active Forum User
Non-VOC Member
I have fitted the Conways anti sump valve and it is a fine piece , worked perfectly . Will certainly operate with a two speed pump .
Sid .
 

Big Sid

Well Known and Active Forum User
Non-VOC Member
On the matter of your oil pump allowing the sump level to rise too quickly . This is due generally to a loose fit between the inner shuttle and the bronze housing . I have successfully swapped the old inner moving member to one having a snugger fit and the problem ceased . This can be done quite easily with no need to break the motor down . In fact the entire pump , housing and all can be swapped without parting the cases .
But an anti sumping valve from Conways solves the entire problem nicely . Three of our motors use valves designed and built by
Bill Jean which have been doing their job perfectly for years . Never a problem . Sid .
 

Albervin

Well Known and Active Forum User
VOC Member
A Conway anti sump valve just sold for over $77 Australian on e-bay. What do Conways charge?
 

Peter Holmes

Well Known and Active Forum User
VOC Member
Question, My Rapide wet sumps horribly, I don't think it did in my early years of ownership from 1965 on, but then I did use the bike pretty much every day, but following a total rebuild by a very well respected Vincent engineer it wet sumps, it is not a problem if I use the bike every day or even once a week, but after that I would need to drain the sump before attempting to start. I did purchase a few years back a Conways anti sumping device but as yet lack the courage to install it, my fear is that as the pump is clearly leaky/inefficient, would it have sufficient power to lift the sprung loaded ball bearing off its seat to allow the full flow of the oil, I believe that some experts are of opinion that at best the standard pump is a bit marginal, by the way, I am not an engineer and do not have an opinion on that. The Conways device seems to require an enormous amount of human suction, about the same effort as when you first try to inflate a balloon but in reverse. I seem to remember Marcus Bowden removing one from a fellow rallyists Vincent whilst in Ireland, I believe the machine was overheating and on the verge of siezing, removing the device solved the problem, might have been Henry Martini, not 100% sure.
I am sure the device is good and is well tested and it is not my intention to "rubbish" it, but my question is, is the device OK to use with leaky pump that presumably is not working to full efficiency when taking into account that is what it is designed to be used for.
 

Howard

Well Known and Active Forum User
VOC Member
Question, My Rapide wet sumps horribly, I don't think it did in my early years of ownership from 1965 on, but then I did use the bike pretty much every day, but following a total rebuild by a very well respected Vincent engineer it wet sumps, it is not a problem if I use the bike every day or even once a week, but after that I would need to drain the sump before attempting to start. I did purchase a few years back a Conways anti sumping device but as yet lack the courage to install it, my fear is that as the pump is clearly leaky/inefficient, would it have sufficient power to lift the sprung loaded ball bearing off its seat to allow the full flow of the oil, I believe that some experts are of opinion that at best the standard pump is a bit marginal, by the way, I am not an engineer and do not have an opinion on that. The Conways device seems to require an enormous amount of human suction, about the same effort as when you first try to inflate a balloon but in reverse. I seem to remember Marcus Bowden removing one from a fellow rallyists Vincent whilst in Ireland, I believe the machine was overheating and on the verge of siezing, removing the device solved the problem, might have been Henry Martini, not 100% sure.
I am sure the device is good and is well tested and it is not my intention to "rubbish" it, but my question is, is the device OK to use with leaky pump that presumably is not working to full efficiency when taking into account that is what it is designed to be used for.

I am an Engineer, and I think you're right to be concerned. I don't like anything that might cause an obstruction between the oil tank and pump - if it can, sooner or later, it will. Fortunately mine only seeps slightly and I automatically drain the sump after a Winter layoff, when/if it gets worse I'll sort the pump. Anti-sumping devices cure the symptom not the problem.

Just my opinion, now wait for comments from satisfied A-S valves.

Just thinking as I type (2 things at once, my wife will be impressed) - maybe we could connect a small electric pump to the drain plug and pump the oil through the return pipe before starting to kick - clears the sump and lubricates the cams.

H
 
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