Wet Sumping

Does anyone have experience with the anti wet sumping valve sold by Colorado Norton Works? I have a 74 850 that has the bad habit of wet sumping. My biggest fear is the valve interrupting oil flow to the pump.

do a search on wet sumping and read till your hart's content. there has been a lot of discussion on this but I personally DO NOT LIKE THEM . I have been in the auto industry for over 35 years and most common wisdom is YOU DO NOT put ANY restriction on the suction side of an oil pump. there is a couple of mods to slow it down but not much of IMHO a RELIABLE sure cure other than riding it often

I think a lot of us fear this also. There are a number of solutions including doing nothing. Some have used mechanical shut off valves where either a switch is activated so you can't start the bike with the oil valve off or the valve handle mechanically interferes with the kickstarter when off (on non e-start models).

There are a lot of past threads on this topic in the archives.

I use a similar valve and have done for 20 years, I always prime the oil line if I disturb it and also check for good oil return on starting the bike and waiting a couple of mins to ensure it is fresh oil and not old oil from the previous run. There is a danger the valve will stick shut regardless of who made it but mine has been fitted to Velocettes for many years.

I installed the CNW in line valve last April.

No problems at all.

I have tested two types of anti wet sumping valves: RGM valve (closed alloy body) and CNW valve (alloy with see-through part in the middle). Compared to using none the RGM type valve effected an oil pressure drop of approximately 10% throughout the rev range where the CNW valve caused oil pressure loss close to nothing, hhmmm??
When I took both valves apart I found out the RGM type valve has a reasonably tight spring to press a steel ball on its seat preventing oil from entering where the CNW valve has a synthetic ball hold by a less tight spring. No need to say which type valve I fitted to my Nortons! Btw so far I did over 10.000 satisfactory miles and yes I do have an oil pressure gauge next to the rev counter.

As mentioned covered to no-end in many threads
I used the see through miles type for a few years, during my last rebuild maybe 6 months ago the valve didn't open and my new motor would of been trashed had i not just been warming it up to change the oil - i noticed no oil circulation and hastily shut it off, thinking at first something else i checked levels etc - once i removed the valve - oil circulation was fine

i'll never use a valve again - while it did prevent wet sumping, if i hadn't caught it when i did my previously " working" valve would of ruined my motor!
m

I have to agree with the "I won't use the check valve" crowd. It is just not worth the risk IMO. Norton wet sumping is just one of the many irritating niggles ... or you could say "character" that most Nortons seem to have. Just ride it more often, or dain it out of the sump when the bike sits too long. Depending on how much oil is in the sump, and how cold it is, it CAN be difficult to start the bike if you don't drain the oil out. Ask me how I know ... cheers.

In my opinion, the safest way to control wet sumping is after the pump. You can be pretty certain oil pressure will open any spring loaded check valve on the pump outlet. Depending upon pump suction to overcome a spring loaded check valve has it's hazards, as I found out. Having an obstruction between the pump and tank is asking for trouble.

As I have mentioned before - I had a 71 Commando back in the day. Sold it in '78. Never knew about wet sumping, never HEARD of wet sumping and certainly never worried about wet sumping. Suddenly NOW we worry about it?

STOP THE INSANITY!

mike996 said:

As I have mentioned before - I had a 71 Commando back in the day. Sold it in '78. Never knew about wet sumping, never HEARD of wet sumping and certainly never worried about wet sumping. Suddenly NOW we worry about it?

STOP THE INSANITY!

Click to expand...

Cause most of us old farts spend most of our time online TALKING about Commandos instead of getting out RIDING Commandos!!

I am strongly in the "just say no to anti-sumping valves" camp as well. Been lots of discussion about it!