Wet sump question?

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kn0ck4times

kn0ck4times

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How much oil drained is too much? I intentionally let my commando sit for a week to see how much oil would drain into the sump. Started with oil line between low and half and after a week oil was off dip stick but could not see the oil strainer/filter. Could/should I kick start it at that level or drain and refill? Really want to do away with ball valve and know there are other options but was just curious.
 
Drain and refill.

Alternative to the ball valve is the AMR mods to oil pump and timing cover and you block off a hole in the crankcase before reassembly.
 
Well the more oil in sump, the harder to kick and greater chance of blowing out the crank seal. Certainly not good to try starting it with level below tank strainer. So, got to do the sump drain and tank top up routine unless you use an anti wet sump solution.
I have a manually operated ball valve with ign cut out failsafe. No more worries.
 
Last year I went away for an extended cross Europe jaunt in my motorhome and returned to a puddle under the bike. It had wet sumped enough to force oil past the crank seal and into the dry belt case, then out via the airways in the CNW inner ‘chaincase’ onto the steel ramp.

This time, in advance of my heart operation, I syringed out all of the oil from the oil tank, and it now sits empty with a large ‘no oil” notice on the fuel tank and the keys are similarly marked up as well.

It took next to no time to remove the oil and there’s no way it can be started empty.
 
Drain the sump and see how much oil comes out to be sure, some bikes will wet sump quicker than others, mine only wet sump when left for 5 months or more I just drain the sump and put the oil back in the tank if its not due for a oil change.
 
kn0ck4times said:
How much oil drained is too much? I intentionally let my commando sit for a week to see how much oil would drain into the sump. Started with oil line between low and half and after a week oil was off dip stick but could not see the oil strainer/filter. Could/should I kick start it at that level or drain and refill? Really want to do away with ball valve and know there are other options but was just curious.
Click to expand...

kn0ck4times said:
Most of us keep oil level at the lower mark, FYI. If you fill it to the top mark, oil will blow out the tank breather. If you only lost oil half way between the marks you are in good shape.
Click to expand...
 
"I have a manually operated ball valve with ign cut out failsafe."

This sounds perfect. Have you shown us that work here on Access? Very interested.
 
Jdub said:
"I have a manually operated ball valve with ign cut out failsafe."

This sounds perfect. Have you shown us that work here on Access? Very interested.
Click to expand...
Though there are a few commercially produced ball valves with ign cut out available (Feked as one for example), I just made one from a hardware store Dahl water shut off valve:

Wet sump question?



This had the correct hose barb diameter and the ball valve opens to that same full flow diameter. For the ign interrupt, got a micro push-button momentary, Normally Open switch and mounted it to a bit of Alu flat. The Flat had a hole to pass over the valve barb, right up against the body flange (left side in this pic). Epoxied it to the valve body plus the feed hose butts up against it. The switch position adjusted such that switch is actuated only when the valve is in fully open position, closing the micro switch contacts, which are on the ign power line from main switch.

Older thread on this topic:

Anti wet sump valve sieze (2015)

Hi, I purchased an oil cut off valve for my 1974 Norton Commando which has two wires that have to be connected to the ignition switch to preclude starting the engine with the valve in the closed position. John D. Could someone post a link to one of these valves? Thanks!
www.accessnorton.com www.accessnorton.com
 
Last edited:
If the level of oil in tank is below the dipstick after a week your pump has excessive clearances inside and needs attention. Fitting a valve will only mask the issue of your oil pump not being able to provide enough oil pressure.
 
I recently rebuilt my 72/73 MK2A Combat Commando using a new MK3 timing cover, new AN oil pump and reground crank with new shells.

So far I have not had any wet sumping, even after 4 weeks of standing. I believe the factors which help include the following:-
- the MK3 timing cover uses a piston arrangement with a spring behind it. The cover piston seals against the oil pump outlet, via a rubber grommet. This arrangement will only allow oil to pass into the timing cover and into the big end when there is oil pressure.
- the AN pump is built selectively and doesn't leak oil
- with a fresh ground crank and new shells, there is much less opportunity for oil seepage past the rod shells.

So a new MK3 cover and pump seemed to do the trick for me, at least for now.
 
kommando said:
If the level of oil in tank is below the dipstick after a week your pump has excessive clearances inside and needs attention. Fitting a valve will only mask the issue of your oil pump not being able to provide enough oil pressure.
Click to expand...
'cept my oil pressure gauge show great pressure right from start up & while riding, yet the bike will fully wet sump 10-14 days after standing.
 
kommando said:
Drain and refill.

Alternative to the ball valve is the AMR mods to oil pump and timing cover and you block off a hole in the crankcase before reassembly.
Click to expand...
"you block off a hole in the crankcase before reassembly."

A couple of questions if I may.
Is this hole the 1/4" X 20 tpi threaded hole between the oil feed and the pressure relief valve? If this is the hole and it is blocked of, where does the excess oil from the pressure relief valve go to?
As this hole is the same thread as the timing cover screws, can an old screw be used with the head cut off with a screwdriver slot cut in the end?

Thanks David
 
Changaroo said:
Is this hole the 1/4" X 20 tpi threaded hole between the oil feed and the pressure relief valve?
Click to expand...

Yes.

Changaroo said:
If this is the hole and it is blocked of, where does the excess oil from the pressure relief valve go to?
Click to expand...

The timing cover needs to be drilled so the oil then vents into the timing chest.
www.accessnorton.com

Is This Part Of The AMR/Nortec Pressure Relief Valve Mod?

Last winter I left myself a "to do" note and now I'm trying to figure it out. It was with my oil pump and timing cover that AMR had modified and returned. I must have printed that photo, but I'm not sure where it came from. Maybe a forum post? I wrote the note, got the 1/4-20 set screws, then at...
www.accessnorton.com www.accessnorton.com

Changaroo said:
As this hole is the same thread as the timing cover screws, can an old screw be used with the head cut off with a screwdriver slot cut in the end?
Click to expand...

Yes.
 
L.A.B. said:
Yes.



The timing cover needs to be drilled so the oil then vents into the timing chest.
www.accessnorton.com

Is This Part Of The AMR/Nortec Pressure Relief Valve Mod?

Last winter I left myself a "to do" note and now I'm trying to figure it out. It was with my oil pump and timing cover that AMR had modified and returned. I must have printed that photo, but I'm not sure where it came from. Maybe a forum post? I wrote the note, got the 1/4-20 set screws, then at...
www.accessnorton.com www.accessnorton.com



Yes.
Click to expand...
Thanks L.A.B.

My timing cover has not been drilled so I will leave it as it is and not block the threaded hole.
David
 
OP question is how much is too much? Has anybody done some evaluations or scientific estimate to come up with an answer in oz or ml?
 
kn0ck4times said:
How much oil drained is too much? I intentionally let my commando sit for a week to see how much oil would drain into the sump. Started with oil line between low and half and after a week oil was off dip stick but could not see the oil strainer/filter. Could/should I kick start it at that level or drain and refill? Really want to do away with ball valve and know there are other options but was just curious.
Click to expand...
You will get lots of answers. I have two depending on if you have a reed valve breather. With a reed valve breather I don't even look I just start the bike. Yes, there a chance that the main seal could still be pushed out, which would be a PITA, but I don't consider that very hard to fix and it's never happened to me. Without a reed valve breather, I drain the sump if I can see that the oil in the tank is down to the screen.

One of my bikes wet sumps fully in two weeks another in around 5 weeks. Both have reed valve breathers and I simply start them.
 
If you have a reed valve breather you can kick the engine over a bunch and enough oil will get pushed past the valve and out of the crankshaft that you can start the bike safely.
 
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