Wet sumping

nortonisthebest · Aug 3, 2014

Hello again,
Now if I could just figure out a way to stop wet sumping on my 1973 Norton. I know there have been much written about the subject but this has always been a problem. I do not want to install a check valve in the oil supply line for obvious reasons. I hate to beat a dead horse but what really works?
Also to stop engine oil leaks I installed a BRAKE VACUUM SERVO valve in the vent line coming from the crank case to the oil tank. This valve has a rubber flapper instead of a ball check which works faster to help keep a negative pressure in the crank case. So far I have no oil leaks.

Hobot · Aug 3, 2014

I'm convinced some wet sump was Norton's wise way to compensate for dry cam starts after the cam oil tub was lost about time Combats arrived. Best simple solution I've seen was a nipple put in rear low TS case so could drain excess out to put in tank before kick off. Could just leave its valve open to drool into catch bottle to save time waiting for sump to drain before a start. Ya ain't gonna forget leaving this drain open or big mess in a few seconds to remind ya and no danger of forgetting to turn on oil flow in drunken stupor either.

1up3down · Aug 3, 2014

I do not want to install a check valve in the oil supply line for obvious reasons.

presumably for the understandable fear of failing to remember to turn the lever ON before a ride

yet in spite of such a fear many of us do exactly that, install a simple on/off lever valve in the oil line, and proceed along in time for many years even decades without incident

some do so by cleverly installing ways to not allow the key to be turned on unless the oil valve is turned on, through either mechanical or electrical means

others, like me, simply remember to turn the valve on, as much an ingrained part of our routine as turning the petcocks on or putting on helmet and gloves (I also have a piece of white duc tape on my speedo that says "OIL" as a reminder I can't miss)

My good friend Tom on this forum puts his ignition key on the valve lever so that he cannot start his bike unless he first removes the key from the lever, this pretty much guarantees that he will turn the flow of oil on!

some install a spring loaded one way valve in the oil line

lots of ways to stop wet sumping that work very well

Fast Eddie · Aug 3, 2014

I bought a new AN oil pump as they claim to be made to tighter tolerances, thereby flowing slightly more and wet sumping less. Bold claims!

I'm running 20/50 at present due to running in (I normally run 20/60) and with this oil, and the new pump, wet sumping is not an issue.

JimC · Aug 3, 2014

Why not use the MK III check ball, the AMR mod, on the oil pump output? You'll never forget to turn it on, nor do you need some Gyro Gearloose componentry to remind you not to destroy your engine. As far as that goes, I'd much rather forget that the crankcase is full of oil than forget the oil is shut off.

john robert bould · Aug 3, 2014

Can all the tank contents end up in the crankcase over time? If so would this result in no oil to the pump on start up?
Steve Hobit suggests this sumping down is good for huge oil splash from the crank "Muck spreadding" on start up. churning lots of oil onto the cam etc.
But if the tank and supply feed is enpty..then no pressure..untill the scavange as refilled the tank?
A check valve turned off after a couple of days is the best...oil in sump for starting and feed line full..Velocettes solve this issue with ball valve under the tank.

nortonisthebest · Aug 3, 2014

Hay all your ideas are good. I like the manual valve in the feed like the best. It's simple and a true Norton guy wont forget to turn it on. Like remembering to drain the sump after a few days before riding. Question; what type of shut off valve would you use? I remember the first Norton commando I owned just out of high school was a 1970 commando and I never heard of wet sumping. I road that bike all over and never had any problems.

john robert bould · Aug 3, 2014

Velocette type, ball and spring.

1up3down · Aug 3, 2014

Question; what type of shut off valve would you use?

I went to a specialty plumbing store and bought a simple WOG valve (water/oil/gas)
that on each side of the lever valve has about a half inch of stepped extensions that the oil lines go over to secure to. A good idea is to put some safety wire on for insurance.

You will want to locate it right in front of the clutch cable coming out of the gearbox.

I am not set up to post pictures but if you email me I will reply back with a photo of my valve showing it place. You can email me at kahrcw9 @ gmail.com with no spaces of course

nortonisthebest · Aug 3, 2014

Hi,
Thanks for the reply. I'll email you shortly. Paul

1up3down · Aug 3, 2014

does anyone recall what is the inside diameter of the oil lines so as to purchase the correct size valve?

is it 5/16 of something like that?

1up3down · Aug 3, 2014

Toppy has PM me saying the oil lines have a 3/8 inch bore

thanks, Toppy!

kerinorton · Aug 3, 2014

ONE OF THE DISADVANTAGES OF WET SUMPING IS ALSO THE OIE MIGRATES INTO the primary case as well. If you ride with the primary case overfill, it ends up on your rear chain and everywhere else. Both my bikes will do this . The high milage 850 now has a manual valve in the feed line which I turn off if I am not going to ride the bike more than once a week. The 750 which has now just done 14,000 miles, does wet sump, but slowly so it takes about a month or 2 to really fill the sump and the primary case. I have another valve ready to fit to that bike a s well.
I am sure the oil lines are 3/8 inch.
Dereck

ashman · Aug 3, 2014

If you ride your Norton regularly you should have no problems with wet sumping, but if you let it sit for more than a week or two then you will have some wet sumping, it slowly seeps down over time, I have never had any problems with wet sumping of my Norton in 37 years as it was a everyday ride but the last 1 1/2 years when I brought a new Triumph Thruxton I am not riding my Norton as much and sitting for a few weeks it wet sumps so I ended up putting a ball valve in the oil line, I have a laylad connected to the tap which runs around my folding kick start so can't kick the bike untill I open the valve.
I will only turn the valve off if the Norton is going to sit for sometime, mine takes about 3 weeks before it starts to wet sump, so not as bad as some others here.

Ashley

DogT · Aug 3, 2014

Plenty of us have installed ball valves in the feed line. I used a 1/2" PEX valve and attached a micro-switch to disable the ignition if the oil switch is not on. The 1/2" pex will fit in the 3/8 line just fine and actually is about the same ID. If you want samples, let me know, I can find the treads.

Dave
69S

texasSlick · Aug 3, 2014

Use the search function above to search on wet sumping.....you will find enough info to keep you occupied for hours.....without starting another round of arguments!

Slick

Hobot · Aug 3, 2014

Not a bad idea to google search terms + accessnorton in case forum engine don't do it for ya. Do scan to 2nd page 1st or will miss some vital reports on actual risk evnts that seem to be more common than fractured axles or failed crank seals which is only thing beside maybe a few seconds smoke by excessive wet sump. Of course a few seconds of oil should be in tank before it starts returning to tank at twice the rate it feeds out.
https://www.google.com/#q=wet+sump+accessnorton

Bernhard · Aug 4, 2014

john robert bould said:
Velocette type, ball and spring.

Velocette type, ball and spring; if using these it is essential that you use clear pipe below the ball valve and look to see if oil is in there every time before you start ( after being left overnight) and prime it full of oil before connecting up.
The ball valve worked a treat on my Venom.

nnnrh · Aug 4, 2014

Can someone explain to me the BIG problem with oil leaking back into the sump, I have never heard of it being a problem except on this forum. As far as I understand and experienced, if it has sat for a while you just start her up and the oil goes back to the tank, end of problem.

auldblue · Aug 4, 2014

Bernhard said:
john robert bould said:

Velocette type, ball and spring.

Click to expand...

Velocette type, ball and spring; if using these it is essential that you use clear pipe below the ball valve and look to see if oil is in there every time before you start ( after being left overnight) and prime it full of oil before connecting up.
The ball valve worked a treat on my Venom.

I have an RGM valve fitted . Checked oil level left bike for six weeks and checked oil again and found my dipstick was too short, started bike and oil return was fine.

J

Wet sumping

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