Wet sumping Myths and realities.

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Well, I came that close to tapping out the drain plug at the sump and screwing in one of those air compressor tank water drain valves. How convenient to just open that little bastard before and after running.
I have a ball valve on the supply line to keep it from filling the sump when sitting for a time. After running I need to either run at idle for a while to bring the sump to an acceptable level, or drain the sump and pour it back into the tank manually. This method can be quicker and more reliable.

These are 2 unrelated issues with the later being the most detrimental. I have fitted a MKIII timing cover with the anti wet sump valve. During this change over or anytime being in the timing chest, I am inclined to remove the oil pump for inspection. This is not the first time I have discovered a piece of piston ring lodged in the return circuit from the PO’s rebuild.

Therefore, I am inclined to conclude that a wet sump condition on a dry sump system is an unbalance between the supply and return circuit. DUH.

Any type of valve on the supply line can be considered as a misleading attempt to cure a much more serious problem and has nothing to do with true wet sumping.

One way flapper or reed valves on the breather are nothing more the slight vacuum enhancers. They’re OK, I have one but the $6 one is as good as any. Oil comes a blowin out that line with or without a hair brained contraption that supposedly helps wet sumping. If all is well with oil flow, I believe the valves are good.

Pressure Relief Valve Pistons and springs should be check or better yet, replaced ($10 buck for both) .

If there is any concern of lack in return oil flow you must do your utmost to verify that your tunnels are clear, up to and including total teardown. Usually the obstruction will be found on the back of the oil pump and the ports leading to it.

Take heed, the crank will take some oil and the time chest could take the rest starving the system.
I’ve heard some tales lately of stuck valves and many, many, theories. A slight lack of lubrication will bind stems in hot guides.
 
Only fully perfectly functioning Commandos I know of with built in riding wet sump issue are '72 Combats with run over 6000 for a time, but they have back up rear oil return via the breather tube. Otherwise there must be some blockage-breakage as you list and I've found too. A drain tap is not a bad idea if you never get close to high centering stuff, like loading in trucks or jacking up or bottom.

Hmm if metal or even magnetic JBWeld were to allow a super magnet to stick on hole with say a silicone thin-soft gasket might just be able to pull that off to drain and then let it snap itself back on, if you don't get fingers in way to pinch.
You likely could not pull it straight off but have to slide sideways off seat over Al to remove. Crazy idea, but would be a low profile labor saver.
 
A magnetic sump cap is a BAD idea!

A stray rock could knock it off.

No thanx.
 
There is a better way to prevent wet sumping, than external valves on the oil pump suctioin line. It is mentioned in a little book put out by the INOC. I haven't done it myself, but I have heard it works from an experienced Norton owner. What you do is put a check valve in the timing cover, on the outlet of the oil pump. To do this all you need to do is deepen a hole in the timeing cover, and insert a ball and spring. Then you need to lap the end of the oil pump outlet tube so the ball will seal nicely on it. This solution has the advantage of being concealed, not effecting the oil pump delivery by restricting the oil pump inlet, and costs almost nothing.
 
tricatcent said:
There is a better way to prevent wet sumping, than external valves on the oil pump suctioin line. It is mentioned in a little book put out by the INOC. I haven't done it myself, but I have heard it works from an experienced Norton owner. What you do is put a check valve in the timing cover, on the outlet of the oil pump. To do this all you need to do is deepen a hole in the timeing cover, and insert a ball and spring. Then you need to lap the end of the oil pump outlet tube so the ball will seal nicely on it. This solution has the advantage of being concealed, not effecting the oil pump delivery by restricting the oil pump inlet, and costs almost nothing.

That sounds like the AMR fix.
 
I had this fix done 15 years ago, when they were still Nortec (before AMR), while it did reduce my wet sumping a bit, it certainly was not a be-all-end-all solution, at least not for me. I have since long gotten rid of the ball check valve, although I have kept the oil pump they machined and added the O-rings to. And I have found that using a shim (from Old Britts) behind the oil pump seal at the timing cover, helps ensure a tighter fit, and reduces wet sumping for me.
 
Real Nortoneer's also know to stop engine parked awhile with the pistons near TDC.

hobot
 
Much ado about nothing.

Norton's wet sumped from the day they left the factory. The rider's manual says to expect it. I have never drained my sump before starting in 35 years and have never had any ill effects from it. Neither have any of my Norton buddies, some of whom have Norton'ed for 40 years.

There are far too many real issues to contend with on these old bikes... wet sumping isn't one of them.
 
Just imagine, if your tank oil has completely drained into your sump. What is going to happen when you start your engine up?
Nothing. It is completely lubricated. The top end can run for miles wthout lubrication, & by the time it is run for a few seconds, the oil would be returning to the tank & lubricating the top end anyway. I ran mine once without any oil getting to the rockers for a few miles as my rocker feed packed up.
Don't worry about it.
 
Right-O, a good owner will peer into oil tank to make sure enough oil remains to feed engine for a few seconds till sump returns more than draining. As stated its standard operation and safe to ride off as soon as can take throttle just as long as supplied at start up with an inch or so of oil still in tank. Actually may be good they wet sump some as first turn or two of crank should fling some oil on cam before any draining from head. Only down side i've heard and I don't really believe it, is can blow oil seals. Frozen thick wet sump may hinder a kick off of course.
 
yes, my name is Don, and I am a wet sumper.

when I first rebuilt this bike, whenever it would sit for a few days, the all too common mess would appear on the floor.
then I installed this velocette style RGM valve. Along with the yamaha crankcase breather mod, no more cleanups, ever.

Wet sumping  Myths and realities.


like anybody else, the thought of a valve between my oil tank and motor can be a bit annoying, to say the least.
So I recently installed this pressure gauge and plumbing (MSC industrial, about $20) onto this aluminum plate I made myself (priceless) now I can see, 20psi at idle, 40+ at speed. Cool.

Wet sumping  Myths and realities.


Wet sumping  Myths and realities.


I got all this done by reading here. Many Thanks, Don
 
"There are far too many real issues to contend with on these old bikes... wet sumping isn't one of them."

Totally agree. It's a non-existant problem for which there seem to be several "solutions." For some reason our Commando's seem to generate a bunch of those (non existent problems with a variety of solutions.)... ;)
 
tricatcent said:
There is a better way to prevent wet sumping, than external valves on the oil pump suctioin line. It is mentioned in a little book put out by the INOC. I haven't done it myself, but I have heard it works from an experienced Norton owner. What you do is put a check valve in the timing cover, on the outlet of the oil pump. To do this all you need to do is deepen a hole in the timeing cover, and insert a ball and spring. Then you need to lap the end of the oil pump outlet tube so the ball will seal nicely on it. This solution has the advantage of being concealed, not effecting the oil pump delivery by restricting the oil pump inlet, and costs almost nothing.
I have a bag of 100 1/4 inch steel ball bearings that I bought just for this mod. Then, I couldn't find the `Spring (.575" free length, .260"diameter - 8 turns of .015 wire) ... THEN, I hear that MKIII's already have some kind of anti-wetsump check ball??? Is it true? Could I not even do this mod on my 75' because it's already there???

BTW I'll send anyone a ball bearing who wants one if you pay shipping + .50 for a box. :wink: Or I'll trade you if you can find one of those springs :mrgreen:
 
"There are far too many real issues to contend with on these old bikes... wet sumping isn't one of them."

Only if you don't mind the troubles I USED to have... oil all over the floor, and lotsa smoke on startup. both have been resolved with the three mods I described, after reading about them here.

(edit) its a greener bike now, the college chicas like that, even if they don't like me :mrgreen:
 
Only if you don't mind the troubles I USED to have... oil all over the floor, and lotsa smoke on startup. both have been resolved with the three mods I described, after reading about them here.

Please explain how wet sumping leads to "oil all over the floor". Crankcases should be sealed, regardles of how much oil is in them.

A crankcase breather is certainly one of those "real issues to contend with". Check valves in the oil line (IMO) are a solution for a non-problem. As wonderful as this forum is, we are as guity of perpetuating the Norton myths as anyone.

Nice gage, BTW.
 
Only if you don't mind the troubles I USED to have... oil all over the floor, and lotsa smoke on startup. both have been resolved with the three mods I described, after reading about them here.

Please explain how wet sumping leads to "oil all over the floor". Crankcases should be sealed, regardles of how much oil is in them.

A crankcase breather is certainly one of those "real issues to contend with". Check valves in the oil line (IMO) are a solution for a non-problem. As wonderful as this forum is, we are as guilty of perpetuating the Norton myths as anyone.

Nice gage, BTW.
 
Thanks Dave for your thoughts... and I do agree, Crankcases should be sealed, and if they are full of oil at startup, well there is no real problem with that except for all the smoke.

But if they are not sealed, the oil that drains from your tank goes through your oil pump, and into the case and then, violla! your shop floor looks like the gulf of mexico.

In a perfect world, none of this would happen. all 40 year old motorcycles would be rebuilt to better than original condition. At the same time, my world is far from perfect, and I don't know how many old british bikes have a compromised seal between the cases, but I would guess it is quite a few.

Cheers,

Don
 
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