Anti-wet sumping valves

[alanaitch]

Hi all
I'm restoring a late A10 (with DA10R engine).  I've seen anti-wet sumping valves advertised a lot and wondered if anyone had a view on whether or not they're worth fitting.

[RichardL]

Alan,

Welcome to the forum. If you have been lurking in the background, reading and waiting to join, you already know that this forum will be a great resource for information and camaraderie.

The topic of anti-wetsumping valves has been discussed here at length with, mostly, negative responses. Go up to the tabs where you find "Home", "Help", etc. and click on the "search" tab. Try entering the words "anti" and "wet" and you find many comments, not to mention the ones that are about to follow from other members as soon as I stop typing.

Richard L. 

[Beezageezauk]

Hi Alan and warm welcome to the forum from me.

If you are in the process of restoring your A10 and have yet to strip the engine I would suggest that you replace the items that causes wet sumping whilst the crankcases are split.  This would be much, much cheaper than buying an Anti-wet sumping valve.

If you have finished the engine, wait until the bike is up and running and you might find that it doesn't suffer from wet-sumping.  Then you won't have any unnecessary expenditure in this area.

Beezageezauk.

[1660bob]

Personal preference here i suppose BUT... If you are rebuilding, then theoretically you will not need one.The primary cause of wet sumping is of course the oil draining by gravity down from the tank and seeping into the engine past the oil pump, the more worn the pump, the bigger the clearences and thus more room for the oil to seep past into the crankcase.If your pump is going to be re-conditioned/replaced it will then be in good nick,seepage will be at a minimum,and if and you use the bike reasonably often, you shouldn`t have any problems. If you splash out on a new, shiny SRM pump (££££££££££££££££) they insist that NO such valves are fitted in case they cause restriction in the supply line,HTH, Bob.

[Richard]

now is the above actually correct or is it the ball not seating properly, the one behind the screw inside the crankcase behind the pump area? different opinions on this, I for one am anti SRM the advice they give is just there opinion, as is all the posts here  there is no reason to fit a more powerfil pump and I know they are a buisiness but they make money on the back of all the people that think they are the bees knees, there are a lot of other suppliers of parts at more reasonable cost.
As for the anti wet sump valves they are a boon if you do have a problem with the oil draining into the sump, many thousands have been sold with very few failures, in fact I would suggest that most problems could be attributed to human error, i.e. fitting the valve the incorrect way around, no proof here as no one would admit to that would they?
This valve is not something peculier to BSA's as I beleive there were manufacturers using this as standard on their bikes
Here endeth my opinion,oh and by the way I do have a valve fitted on the S/R and I am still awaiting the failure after three years of riding with it on
Richard

[rocket man]

i and if it does fail it will kill your engine i wouldn't put a valve on Richard you may be a lucky one
if it wet sumps put a sump plate kit on they come with a bolt which has a magnet on the end
which is handy as it picks up metal particles mine has one fitted if your bike is stored over winter
and not used it will wetsump all you have to do is take bolt out drain oil check magnet with it being
newly built there could be some metal particles on it then at least its court them before they recirculate
in the oil in my opinion i would never fit a antiwet sump valve there not 100 percent guarantied to work
all the time if a particle of something gets in the valve whats to say it wont stop it working or if its a valve
that you turn off and on you might forget to turn it on and then it will cost you ££££££££££££££££££££££
to fix thats only my opinion

[bsa-bill]

I'm with Richard on this one.
Everything that rocket man says is also true of the other THREE ball and spring valves that BSA incorporated in the design of the engine.
And please don't tell me the anti sump valve is different because it is sucked open instead of pushed open, the ball valve in the sump pickup is also sucked open.
This discussion has a touch of deja vu, and IIRC there was a request for anyone with experience of engine damage due to failure of an anti sumping valve to come forth, did anyone?
I'm also not a fan of fitting taps, even ones connected to a kill switch, just more opportunities for gremlins and senior moments, these days I would trust a ball and spring much more than my memory I'm afraid.

All the best - Bill (from a cold day in the UK)               

[trevinoz]

Bill,
           I will come forward. I have seen the results of a failed valve on a Commando.
It was not pretty. It needed a crank grind, new pistons and rebore and new bearings.
Very expensive!
My opinion is that the oil had drained from below the valve which then had the pump trying to pump air.
Trev.

[Richard]

Trev ,
How did the valve fail, as the ball has the spring under it and the pump sucks the oil past the seat, did it jamm up? as if it just stopped acting as a valve then the oil will pass the ball and it will just wet sump as it did before but still let oil to the pump, could it have been a case of something else that caused the engine failure and the valve being blamed?
Richard

[Brian]

Much has been written on the pros and cons of fitting these devices, personally I see no need for them and would not under any circumstances fit one.

Like Trev I have seen the result of a engine being starved of oil. In my case it was a 441cc unit single that had a tap in the line and the owner forgot to turn it on. I got the job of rebuilding it, new bigend, piston etc etc. very expensive.

However, there are owners who choose to fit them and that it their choice, just remember if you do fit one and it fails and costs you a fortune to rebuild your engine then dont complain. Everyone knows they do pose a risk and occasionally do fail, if you are prepared to accept the risk then that is your choice.

[Triton Thrasher]

Trev ,
How did the valve fail, as the ball has the spring under it and the pump sucks the oil past the seat, did it jamm up? as if it just stopped acting as a valve then the oil will pass the ball and it will just wet sump as it did before but still let oil to the pump, could it have been a case of something else that caused the engine failure and the valve being blamed?
Richard

My interpretation of Trev's post is that the oil between the valve and the pump drained down through the pump and the valve stopped oil from the tank taking its place, while the engine was stopped, so the pump lost prime.

If you fit a valve and the oil supply fails, the valve is the most likely cause.  What else would do it?

[Triton Thrasher]

the ball valve in the sump pickup is also sucked open.
         

But can't destroy the engine.

[trevinoz]

Richard,
             When there is no oil between the valve and the pump, there is no suction so the ball cannot be moved from it's seat. In my case, the valve didn't fail. If it had been primed it would have operated satisfactorily but I assume the bike hadn't been started for a while thus allowing the oil to drain away. It had worked previously so the owner assumed it would continue working.
I reckon any shut-off device is a disaster waiting to happen.
Trev.

[MG]

As a mechanical engineer, I totally agree with Trev on this one. The oil pumps used in our BSAs are nothing but simple external gear pumps. In it's basic design, an external gear pump is not working well under critical suction conditions. This is a matter of fact and each serious book on work machine or hydraulic engineering will tell you so.

Have a look at this link, esp. at the part of "Installation issues":
http://www.e4training.com/hydraulic_pumps/B1.htm

Imho, if the pump is not leaking, the shut-off valve is not likely to cause any trouble, because it is easily sucked open by the primed pump. On the other hand, if it is leaking, it will run dry and might not be able to create enough suction to open the ball valve that is cutting off oil supply. The BSA engineers did well know why to put the ball valve on the pressure side of the pump and mounted the oil tank far higher than the pump itself to ensure proper priming.

The ball valve in the sump is a completely different story. It is NOT spring loaded, unlike the anti-wet sumping valves, so the ball will easily be lifted off it's seat, once the sump is running full of oil, so oil is forced to the pump within seconds just by hydrostatic pressure, if the oilway to the pump should be empty for any reason (like after a rebuild, for example)
And have you ever asked yourself why the BSA engineers fancied to put this valve there? Imho it's only task is to keep the oil in the oilway leading to the return side of the pump when the engine is stopped, in order not to have it run dry at startup.

Just my personal opinion, but I consider these valves to be a rather safe way to a complete engine rebuild, sooner or later. And if your oil tank is empty after just a few days without riding, you should do something about your leaking oil pump. It is a matter of curing the illness, not the symptoms.

[bsa-bill]

OK gents plenty to ponder and it does really come to personnel choice of course.
As an aside after I rebuilt my Flash I removed the anti sumping valve as it was no longer needed, but as a stop gap cure it was brilliant.

All the best - Bill