Wet Sumping AGAIN!!!!!!!

I've searched through numerous threads about this but can't really find the answer that defines "Wet Sumping" How much oil are we talking about here, the full tank, half a tank, and over what period?
I have a 73 and was curious to see how much oil was in the sump after sitting for 4 days since last start up, does 200cc's come under the "Wet Sumping" criteria? :?:

It can happen overnight, or it can take days or several weeks for the contents of the oil tank to drain to the sump (as it must-due to gravity) and it often varies between individual Commandos due to the condition of the oil pump, oil type and viscosity etc..

200cc over 4 days doesn't sound too bad.

I would say that technically any oil in the sump is "wet sumping"...however, I wouldn't think it should matter a bit unless it causes trouble starting the bike. A severely wet sumped bike is harder to start and you can blow out your crank seal by over pressurizing the the crankcase (usually from revving too high before the oil is evacuated). If you can't tell if there is oil in the sump when you kick it, then it is inside "normal". And no, I do not have data as to how much oil it takes before you have trouble starting, but I can tell on my bike when I have gotten there.

Russ

t can happen overnight, or it can take days or several weeks for the contents of the oil tank to drain to the sump (as it must-due to gravity) and it often varies between individual Commandos due to the condition of the oil pump, oil type and viscosity etc..

200cc over 4 days doesn't sound too bad.

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This is the sad facts of the critter, varies with moon phase and what neighbors were thinking last time they heard you. I've taken to pressing kicker till full resistance near TDC to leave crank throws at top to help stifle the gravity advantage - which sometimes works well but just as often don't, for smokeless warm ups or 30 sec smoking after a few seconds teasing smokeless. Check valves are a type of British Russian Roulette.

My Combat practice is start and throttle right up to 2000+ cam/lifter oil surf rpm and hold it there most a min to get sump sucked down before I idle down to leave. I've heard the tall tales warning of blowing out seals and such but think that a mother's story told to young children as no way to over pressure the crank case if there is any type breather factory to after market installed. Best time to check oil is on first shut down as if oil below the tank drain then dry running till sump refills tank or if adding enough oil to start may find it over filled a minute later. Or assume Cdo worship postures to drain sump by hand.
I fully expected to find worn cam-lifter faces after 7000 miles of this - only opened up d/t ring gap blow up error, to be nicely surprised that the cam/lifter surfaces polished better than first installed.

Just to be clear here, the normal amount of oil left in the sump after running can be as much as 200cc and 150cc, give or take, is normal. This is what drains down from the head and timing chest into the sump area. I can go for a drive (ride), pull into the garage, shut it down, turn off my oil shut off and the next morning drain off 5 to 7 oz (150 to 200cc). "Your results may vary."

CAUTION
Crying "Wolf" around here will gather many a woodsmen.

Despite what everybody says - if you are concerned then fit a tap with a failsafe feature - I personally don't like spring-loaded anti-drain valves. My engine was rebuilt with all new parts, it runs a treat but even with a new oil pump it still wet-sumped. I fitted an in-line tap in the oil tank feed equipped with an electric micro-switch that disconnects the electronic ignition if the tap is not turned on. This setup has been in place for about six years and works perfectly - I can leave the bike for months on end knowing that the oil in the tank will still be there when needed.

mwoo said:

Despite what everybody says - if you are concerned then fit a tap with a failsafe feature - I personally don't like spring-loaded anti-drain valves. My engine was rebuilt with all new parts, it runs a treat but even with a new oil pump it still wet-sumped. I fitted an in-line tap in the oil tank feed equipped with an electric micro-switch that disconnects the electronic ignition if the tap is not turned on. This setup has been in place for about six years and works perfectly - I can leave the bike for months on end knowing that the oil in the tank will still be there when needed.

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I totally need that setup...

Do you have a recommended source for the tap?

Cheers,

- HJ

How about an explanation or pic of your micro-switch setup. I've been trying to come up with one that doesn't look like rube goldberg.

A 1/2" PEX fitting works fine.



Dave
69S

Rube Goldberg, you mean like this....hey it works, and yes there have been a few times that I have tried to start the bike WITHOUT TURNING THE VALVE ON.

It's totally dependant on the phases of the moon (gravity fluctuations) and oil pump health (mileage ?) and oil viscousity after shutting off the motor (hot ?)and piston position after shutoff and choice of oil and it's BRITISH ! oops ,tea time.

Why does piston position at shutdown affect this? Just wondering.

seems as though on mine if I can get the pistons right at TDC I'm golden. If I stop just short she'll sump a bit. I took her out yesterday after a 2 month sit and the oil tank was still full. I usually hit this about 75% of the time. Every onece in a while though she leaks through. I attribute that to not having things quite at TDC but I might be wrong.

MikeG said:

Why does piston position at shutdown affect this? Just wondering.

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Basically, with the crankpins left at, or near TDC, the head of oil (in the tank) is reduced to its minimum, so the rate of drain will be slowed as the oil must climb back "uphill" for a short distance in order to finally escape from holes in the big end journals.

If the crank is left with the crankpins near BDC then the oil can simply travel "downhill" all the way-so drains more quickly.

DogT asks:

How about an explanation or pic of your micro-switch setup. I've been trying to come up with one that doesn't look like rube goldberg.

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I see the picture of the one way mechanical valve and I see a wire.....

so how does the wire involve itself in the valve, is there some contact made with the lever and the wire that sends a signal to the ignition that it is now ok to turn the key?

for many years I ran with just a mechanical valve, and at times a tried a fishing leader line between the lever and the ignition key so that I could only turn the key to on if the lever was in the open flow position

this works well in "theory" but in actual practice the wire and its connections stretched.........

so, I am very interested in hearing more about safe guarding the lever being on with an electrical solution?

It would be a lot easier to make one with a contact that grounded out the ignition when it was closed. It would depend upon your ignition system as to whether or not this was practicle.

Some ignitions, yes...some no!

Russ

Following on from my contribution the details are as follows:
1) The tap I used is a UK gas tap (gas as in gas - not gasoline) that accepts microbore central heating copper pipe. I bought it from B&Q in the UK. I fabricated a small bracket to fit the tap below the oil tank and then fitted a small spring to the tap lever that attached to a microswitch bolted to the same bracket. The microswitch energises a 30 amp relay that connects the entire 12v supply to the bike's wiring loom thus if the the tap/switch is not set to the 'on' position no electrics work i.e. no lights, ignition etc.
2) It's rather pointless specifying parts etc. for this as, depending on where you are in the world, components will vary. All I can say is that, as Norton Commando owners you will be used to improvisation etc. thus if you feel inclined to try this solution to wet-sumping give it a try - as I stated the principle works perfectly.

That helps.

So the microswitch is a contact switch separate from the tap.

Cheers,

- HJ

lrutt said:

seems as though on mine if I can get the pistons right at TDC I'm golden. If I stop just short she'll sump a bit. I took her out yesterday after a 2 month sit and the oil tank was still full. I usually hit this about 75% of the time. Every onece in a while though she leaks through. I attribute that to not having things quite at TDC but I might be wrong.

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I'm going to try this next time I come back from a ride. I always leave it up on a compression stroke, but it's hard to get exact TDC. Sitting for a week it will usually drain down to the very tip of the dipstick if the oil is at the "high" mark when I park the bike. To ensure that I'm exactly at TDC, I'll pull the plugs and check the piston position. It will be an interesting test.

Recently I had the condition mentioned above, where oil had drained from the tank to the point where it was just barely registering on the dipstick. I've got a CNW breather installed and I'd heard that this will facilitate returning oil to the tank if wetsumping has occurred. I started the engine and let it idle, looked into the oil tank and saw a very steady and strong stream of oil returning from the breather pipe. Oil pressure was strong from the moment the bike started. No smoke, no leaks, no issues. It took a minute or so and the stream from the breather pipe tapered off and quickly stopped completely. I wouldn't do this if the tank had completely drained into the sump, but as long as the oil pickup in the tank was fully covered with oil I thought I'd give it a try. The CNW breather returns the oil to the tank quickly...

mwoo said:

Following on from my contribution the details are as follows:
1) The tap I used is a UK gas tap (gas as in gas - not gasoline) that accepts microbore central heating copper pipe. I bought it from B&Q in the UK. I fabricated a small bracket to fit the tap below the oil tank and then fitted a small spring to the tap lever that attached to a microswitch bolted to the same bracket. The microswitch energises a 30 amp relay that connects the entire 12v supply to the bike's wiring loom thus if the the tap/switch is not set to the 'on' position no electrics work i.e. no lights, ignition etc.
2) It's rather pointless specifying parts etc. for this as, depending on where you are in the world, components will vary. All I can say is that, as Norton Commando owners you will be used to improvisation etc. thus if you feel inclined to try this solution to wet-sumping give it a try - as I stated the principle works perfectly.

Click to expand...

That's pretty much what I was thinking, a spring attached to a switch, kind of like the universal brake stop light switches, I just haven't found a very elegant way of doing it. I wasn't even going to use a relay if I could find a switch that will handle the 4 or so amps of just the Pazon. If the Pazon isn't energized, it won't start. Jay Leno has a setup that includes a buzzer, but I don't see any details.

Dave

I've tried to upload a couple of photos but I'm damned if I can work out how to do it !!!. All I've managed so far is to open a Photobucket account and upload the photos to that (as per the help section of this website). There MUST be an easier way to do it (I have a copy of Photoshop - could that help ?)