MK3 engine oil change with an ant-wet sumping valve

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Soundbite

Soundbite

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Hi All… I’ve just completed my first engine oil change to a newly acquired MK3 Commando. The previous owner fitted an automatic anti-wet sumping valve (see pic - https://www.gtdc.co.uk/norton/wet-sump-valve.html) which I was surprised as I assumed the MK3 had this modification? Anyway, I also drained the old sump oil out, cleaned both gauze filters, replaced the main oil filter and replenished the oil tank with 20/50. So far so good but having read some horror stories about anti-wet sumping valves I felt it wise to check the oil flow from the tank return outlet while both sparkplugs were removed and turning the engine over via the electric start. After a few prods on the button there’s not much returning oil, only a suggestion. Hmmm… I primed the new oil filter with 20/50 before screwing it on but is there a chance an air pocket is preventing the oil pump returning oil? Should I remove the inlet oil pipe on the crankcase side of the valve and prime that with oil before firing it up? Should I remove the valve altogether? Perhaps I’m being over cautious… what do think?
 
Soundbite said:
Hi All… I’ve just completed my first engine oil change to a newly acquired MK3 Commando. The previous owner fitted an automatic anti-wet sumping valve (see pic - https://www.gtdc.co.uk/norton/wet-sump-valve.html) which I was surprised as I assumed the MK3 had this modification? Anyway, I also drained the old sump oil out, cleaned both gauze filters, replaced the main oil filter and replenished the oil tank with 20/50. So far so good but having read some horror stories about anti-wet sumping valves I felt it wise to check the oil flow from the tank return outlet while both sparkplugs were removed and turning the engine over via the electric start. After a few prods on the button there’s not much returning oil, only a suggestion. Hmmm… I primed the new oil filter with 20/50 before screwing it on but is there a chance an air pocket is preventing the oil pump returning oil? Should I remove the inlet oil pipe on the crankcase side of the valve and prime that with oil before firing it up? Should I remove the valve altogether? Perhaps I’m being over cautious… what do think?
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All external anti wet sump valves controlled by a ball bearing, which I assume you have, should be primed with oil below it or they simply don't work.
The ball bearing itself should be 3/8 inch diameter, IMO, or its simply too small to allow enough oil to flow past it.
Tip, fit an oil & heat proof clear plastic, non plastic pipe below ball balve, that way you only have to do a quick glance to see it filled with oil.
 
Bernhard said:
All external anti wet sump valves controlled by a ball bearing, which I assume you have, should be primed with oil below it or they simply don't work.
The ball bearing itself should be 3/8 inch diameter, IMO, or its simply too small to allow enough oil to flow past it.
Tip, fit an oil & heat proof clear plastic, non plastic pipe below ball balve, that way you only have to do a quick glance to see it filled with oil.
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Thanks Bernard, I had my suspicions that may be the case and the only way to implement a capillary action is to prime it with oil below the valve.
 
Chances are that the lack of oil return is due to having drained the sump. It can take up to a minute or so with the engine running
before enough oil collects in the sump for the oil pump to returning it to the oil tank.

Get rid of that anti sump valve. It will only cause worry. Replace it with a manual ball valve with an electrical inerlock to the ignition.
Feked in GB sells a nice one.
 
'Might' being the operative word.... Fortunately I've not had a problem with, though am aware it's not across the board with these machines :-(
 
There is more than one route to the sump, plus the plunger inside the MK3 cover can jam open.

The other route is from the feedside of the pump through the shaft clearances into the scavenge side and then into the sump. The solution is to machine the pump for O or X ring seals.

MK3 engine oil change with an ant-wet sumping valve
 
I’ve had anti sump valves on both bikes for years and no issues. I also have a oil pressure warning light. I’d never put in a ball valve
 
Soundbite said:
I'll probably scap it as I don't think it's worth the anxiety of a cooked engine. I'd rather live with wet sumping as it's easy to check and sort.
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You n me both!

I fitted the Comnoz sump plug breather now sold by NYC Norton. Not only is it an excellent breather, is also helps to rapidly dump excess sump oil back into the oil tank. Well worth a look:

Reed Breather Kit

The Norton twin cylinder engine creates a serious amount of pressure in the crankcase as the motor spins. Over the years the factory attempted several methods to reduce this pressure – from a timed breather off the end of the cam on earlier motors, to a crude straight pipe from the timing chest on
nycnorton.com
 
Soundbite said:
I'll probably scap it as I don't think it's worth the anxiety of a cooked engine. I'd rather live with wet sumping as it's easy to check and sort.
Click to expand...
Soundbite...You have chosen the red pill! Answer...Never put a valve or check valve/ball valve on the suction side of the pump. You have chosen wisely. blue pill blissful ignorance.
 
I have an anti-sump valve which hasn't given a problem. It takes a minute or so for the oil to return after an oil change. I check for oil flow before most rides. It comes quickly.
 
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