Author Topic: Anti Wet sumping valves  (Read 653 times)

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chaz

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Re: Anti Wet sumping valves
« Reply #15 on: 06 February, 2022, 21:29:57 »
:) :) :) :) 

If you have a point where air can get in you would also have an oil leak. If no oil leak then not enough air sucked in to create an air lock. My opinion. But it is good practice to check the oil return on start up, though even with a complete oil sup full it would still return.

Very good Julian. Going back to ignition left on: a bleeper fitted to the ignition/generator light would do the trick. As soon as the warning light comes on it would bleep and tell you that you were about to be silly. Simples. Now why had I not thought of that before????

Mike 8) 8) 8) 8)

Mike
your next task, a warning system to let you know you have left your arm out when turning left or right. some car drivers around here could do with one.

MGI

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Re: Anti Wet sumping valves
« Reply #16 on: 07 February, 2022, 17:55:30 »
I am confused . com reference leaving the ignition on causing wet sumping... Many many BSA's have no ignition switches but if they did or if they do, how does that encourage wet sumping? Similarly, why does leaving the piston at TDC often alleviate the problem - I am not denying this phenomena but would welcome erudition.

Call me old fashioned!

berniej

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Re: Anti Wet sumping valves
« Reply #17 on: 07 February, 2022, 18:28:52 »
The thirst of one who seeks erudition must be slaked....  :)

I can offer only a mere a sip....

I think Dave's point about the influence of piston at TDC must be related to a specific engine layout.

A single - or 360 twin - with white metal big end bearings would maybe provide more resistance with the journals higher up as the pressure head from oil tank to the journal oil feed holes is then at the minimum so that certainly makes sense theoretically. In practice? Not sure.

For roller big end engines I doubt it would make much difference (and my M21s are them wot wet sumps worst!)

Ignition on won't make any difference (unless there's a solenoid valve in the oil feed line activated by the igniiton) but even then you wouldn't leave the ignition on long enough without the engine running for it to wet sump - except by accident which would likely result in a flat battery and likely a rather overheated coil(s)....

Cheers,
Bernie



'49 M21/B31 hybrid
'56 M21 combination
B40 Super Star
A50CC project

DAVE BRADY

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Re: Anti Wet sumping valves
« Reply #18 on: 07 February, 2022, 19:49:48 »
Hi,

The idea of leaving the engine at TDC came from a previous discussion about the wet sumping phenomena.  It is most certainly related to the reduced difference in height between the big ends and the head of oil.  I suspect that it can only ever help to reduce oil seeping through to the sump.  As mentioned the tolerances in the main bush and the wear in the pump etc. will be adding to the problem.  I tried this on an A65 with end feed conversion and did noticeably slow down the wet sumping.
The cure that I am trying implement is to ride or at least run our bikes more often so that not that much oil gets through.

Another habit I am trying to adopt is to alway make sure I check the oil level after a ride so that I top up an engine with no excess oil in the sump.  Obviously check the tank after a period of non-use but if it looks low but OK to run, start up and run to get any oil in the sump back to the tank.  If the tank is topped up without doing this the result could be an over filled tank.  I know this to be true and it can end up in a lot of oil coming out of tank breather and what a mess that can make.
 
Dave.
« Last Edit: 07 February, 2022, 19:59:11 by DAVE BRADY »

griffo

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Re: Anti Wet sumping valves
« Reply #19 on: 08 February, 2022, 08:08:53 »
  For me the anti wet sump valve is the perfect answer. I have used one on A50,A65,B31, c15, C12 and DB32 . If fitted correctly they just do not fail or drain and leave an air gap. To do this you ALWAYS fir the return valve below the pump . That means gravity cannot empty the pipe. Yes all the bikes have done lots of miles with the said valves.. There are some nasty tales going round about them . It's not the valves , usually the fitting of same....
Safe riding saves pinch marks on the seat...

B25ssSteveA65

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Re: Anti Wet sumping valves
« Reply #20 on: 09 February, 2022, 14:38:37 »
Thanks to all who have replied. I see that the (supposed) problem arises due to poor fitting practices both in position and in manner. Once again, thanks.