MK3 engine oil change with an ant-wet sumping valve

Niagara850 said:

lol

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LOL until it goes boom!

@Soundbite don’t listen to anyone else, or any of our horror stories.

Take your valve off, hold it up to your mouth and suck on it.

Then make the decision for yourself about whether you’re ok with an oil pump that was designed in the 1930s and hasn’t changed much that is pumping air instead of oil has got sufficient pumping ‘oomph’ to pull that ball bearing open.

Fast Eddie said:

You n me both!

I fitted the Comnoz sump plug breather now sold by NYC Norton. Not only is it an excellent breather, is also helps to rapidly dump excess sump oil back into the oil tank. Well worth a look:

Reed Breather Kit

The Norton twin cylinder engine creates a serious amount of pressure in the crankcase as the motor spins. Over the years the factory attempted several methods to reduce this pressure – from a timed breather off the end of the cam on earlier motors, to a crude straight pipe from the timing chest on

nycnorton.com

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Great website and quality products! Thanks for the heads-up.

My MKIII takes many weeks to wet sump but not always. It took me a while to put it all together but mine has had the conical seal from the pump to the timing cover fail twice. I have an oil pressure gauge fitted and that catches it. What I now have surmised it that when I see the bike start to show signs of wet sumping after only a few days the seal has probably begun to split. It's not enough to loose much oil pressure but it's enough to let oil drain back past the stock valve because the split starts at the seal face where the valve seats.

I highly recommend an oil pressure gauge because oil returning to the tank is NOT an indication of good oil pressure. If the conical seal fails it simply dumps oil into the timing chest and the sump pump dutifully returns it to the tank. Plenty of oil circulates but not to where it really needs to go.

lazyeye6 said:

Yes, combine this the Reed Breather Kit

Engine & Transmission :: Engine Upper :: Oil Feed Pipes :: Anti Wet Sump Oil Pipe Tap With Switch - Magneto or Coil Ignition Systems

Anti Wet Sump Oil Pipe Tap With Switch - Magneto or Coil Ignition Systems A solution to a frequent problem of wet sumping. Available in two types - please selection option MAG TYPE: Magneto ignition engines - closed circuit - Tap OFF (to earth the magneto

www.feked.com

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On a mk3, I have an automatic anti sumping valve in the oil feed, about 4"-6" after the oil tank. I'd like to replace it with one of these, but am unsure how it would be wired in. I still have 2 x 6v coils with a Boyer ignition. Is it simple to do and in a way that avoids the new wiring being obvious?

On a MK3 with the non return valve already in the timing cover dump the current extra valve completely and fix the MK3 valve issue by doing the oil pump mod with O or X rings.



The kill switch gives enough issues without adding more electrical problems with another switch in the ignition problem and adding a second anti sump valve with the second one being the wrong side of the pump.

Mart UK said:

On a mk3, I have an automatic anti sumping valve in the oil feed, about 4"-6" after the oil tank. I'd like to replace it with one of these, but am unsure how it would be wired in. I still have 2 x 6v coils with a Boyer ignition.

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Not disagreeing with what kommando said but it has to be safer than an auto-valve so from the Fecked page...

"Coil Type explained: Simply use the two wires on the switch to interrupt the power supply to your ignition system. This can be wired in series with the coil low tension wire..."

That would be for points ignition.


"..., or a power feed wire to the ignition switch (care with amperage use)..."

That would be connected in series somewhere between the battery(-) main fuse (for standard positive earth) and the ignition switch ('NU' brown/blue wire).


"...or a power feed to the electronic ignition unit."

The "power feed to the electronic ignition unit" (Boyer in this instance) is the 'WY' white/yellow from the kill switch (assuming the kill switch is connected) so connect the valve between WY and the Boyer box white (for positive earth).

Mart UK said:

Is it simple to do and in a way that avoids the new wiring being obvious?

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Going by the Feked picture the valve wires will need to be extended to reach where WY connects to the Boyer box but should not be difficult to hide.

IMHO - I would always fit an oil pressure gauge. The mechanical gauge doesn't lie, and whether you have an AWS valve installed or not, it provides a lot of prognostic information. Knowledge is power.

I also run a digital voltmeter, but that is another story for a different topic...

76 Mk 111 , purchased with a rebuilt motor.
The ball check valve had stuck closed on the previous owner.
Damage was : Thrown timing side rod hitting the upper case. Welded up.
Both crank journals scored / damaged. Undersized regrind with shells.
Scored cylinder liner where rod nut piece was dragged about. Oversize rebore and pistons.
Camshaft replaced.
So... don't go there.

I rebuilt a MK3 motor for someone because of an inline valve.
No great damage because it was caught in time. Rod bearings were down to the copper plating and the crank needed to be reground.

I will briefly install an oil pressure gauge on any new motor. You'd be surprised how often the rocker spindles are in backwards.