Anti-Drain Tap

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mwoo

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Hi Guys - I'm getting fed-up with the wet sumping on my Commando. The engine has been rebuilt and has only 500 miles on the clock. It runs beautifully and burns very little oil however it still wet sumps (I know, I know it shouldn't with a recond oil pump) but what the hell !!.
I don't like the idea of an external anti-drain valve but rather fancy an oil tap (with it's inherent dangers - I intend to cope with this). Have any of you fitted such a tap and where can I get suitable item(s). It needs to be fairly compact to be accessible. Any tips greatly appreciated.

Cheers
 
It seems there is a safer but more expensive solution, the MK3 timing cover. I consider going for this since I'm getting fed up with wetsumping.

/Per
 
Mark
British Bike Connection in Rochester, NY http://www.britishbikeconnection.com/
Jim has an anti sump check valve for Norton’s. Your idea is ok until you have a brain fart...(" Momentary Laps of Reason" for us older folk) :lol:
You may remember every time...but you have allowed "Murphy's Law" to saddle up behind you.
The INOA Tech digest has a mod for the oil pump but it entails pulling the timing cover off and getting the pump out again. This is a great book for $20 US. IMO
CCN
 
It seems there is a safer but more expensive solution, the MK3 timing cover.
Click to expand...

Per,
Dont' bother. The stock Mk3 check valve is aluminum riding in aluminum. The valve sticks in the open position rather often and the engine wet sumps anyway. I have toyed with the idea of fitting a brass sleeve, but it is so far down on my list of projects I may never get to it.
 
I've had good results with the AMR
mod. Send them the oil pump and your timing cover and what you get back stops the wet-sumping. It's a check ball on the pump output and the pump is fitted with oil rings. Seems the pump itself leaks, as well as oil passing through the pump.

I agree totally with Ron. Anything in the feed line is an invitation to disaster, IMO. Tried the spring loaded in-line check valve. Had zero oil pressure at idle when the oil was hot and that's with a new oil pump.
 
Ron L,

The stock Mk3 check valve is aluminum riding in aluminum.
Click to expand...

Has your Mk3 got an aluminium non-return piston? I've taken one or two Mk3s to bits and they are all steel. My old high milage Mk3's non-return has never stuck. I know I shouldn't have said that, it'll probably fail tomorrow just to put me in my place.

Cash
 
Mark, Mick Hemmings advertises an anti drain valve on page 12 of his catalogue.
 
Thanks Ron, I'll save the timing cover money and spend a portion of it restoring the oil pump instead. A fresh pump combined with always leaving the pistons at top would probably redice the wetsumping to a "manageable" level.

Cheers, Per
 
Since the pump is lower than the oil tank gravity does it's job of feeding the pump at rest. Unfortunately, the oil will seep through the gears even though they are unmoving. I believe oil also seeps out the body of the pump as well. I tried a new oil pump with negligible results. Somewhere before the feed to the crankshaft the oil must be stopped to prevent wet-sumping. Also the pump must not leak oil into the timing case. As I mentioned before AMR does a very good job of this for a very reasonable price. I''m not hawking AMR, it's just that I've tried all the other measures you mentioned and they didn't work.
 
My 74 850 used to drain all its oil into the crankcase if the bike sat for over 2 weeks without running. I got tired of draining the crankcase and refilling the tank everytime I wanted to ride, so I installed the anti wetsump valve offered by Colorado Norton Works. Cost about $80 and eliminates the wetsumping completely. No problems at all. CNW told me that they install this valve on all the bikes that they rebuild.
 
Fitted a Velocette anti-wet sump valve into the oil pump feed line of my Commando and it has worked perfectly. The valve is directly below the tank and out of view so you don't even notice that it is there.
 
Has your Mk3 got an aluminium non-return piston? I've taken one or two Mk3s to bits and they are all steel.
Click to expand...

Uhh...Cash, you could be right, my Mk3 timing cover hasn't been off in a few years. I remember polishing the bore, but the piston may be steel. In any event, it wet sumps as bad as my pre-Mk3's.
 
My MK111 wet sumps pretty quickly too. I got fed up with having to drain the sump before riding if left sit for a few weeks. I thought I would just run the bike and let the pump return the oil to the tank. This can be OK if the quantity of oil in the sump is not too great and if you keep the RPM down below 3000 for the first fifteen or twenty minutes of riding. You should also check right off to see that oil is returning to the tank OK.

I got a bit heavy on the throttle and blew out the crankcase seal which is a lot more work to deal with than draining the sump is.

I'm back to draining the sump if the bike sits much more than two weeks.

My rule for now is if the oil tank dipstick still shows some oil then I ride slowly for fifteen minutes but do not drain. If the oil is below the bottom of the stick then I drain the sump and dump the oil in the tank.
 
I got a bit heavy on the throttle and blew out the crankcase seal which is a lot more work to deal with than draining the sump is.
Click to expand...

If you have a crankcase with positive pressure that will happen when it's filled with oil. With a negatively pressurized crankcase the seal will remain intact. Breather check valve is a must, IMO.
 
Reggie said:
Mark, Mick Hemmings advertises an anti drain valve on page 12 of his catalogue.
Click to expand...

Catalogue? Does that guy even have a website yet? I've never seen a Hemmings catalogue.
 
Coco said:
Does that guy even have a website yet? I've never seen a Hemmings catalogue.
Click to expand...

There's certainly been a Hemmings paper catalogue available for quite a few years now. And it has also been on the Internet for a while: http://www.mickhemmings.com/ >Latest Catalogue. Presumably it is sponsored by Mick Hemmings? Before it appeared on line I did ask Angela (Mrs. Hemmings) some while ago if they would consider setting up a website and was told, in no uncertain terms: -"NO...they would not!"

I thought I'd give Hemmings a call to find out the latest information and spoke to Angela, she said the website is sponsored by Mick Hemmings and the 2005 catalogue is still current as far as parts availability is concerned, and if anyone wishes to place an order (Mick Hemmings Norvil parts are his own so best to contact Hemmings about them) but she said to use the ANIL website prices as a guide as the ANIL prices are continually increasing at the moment. I did hint about a "proper" website but that didn't go down too well again! So don't expect one in the near future.
 
Is wet sumping really all that big a deal? If you ride your bike regularly it won't have time to wet sump. If you leave it for a few weeks, just drain the oil out of the crankcase, put back in the oil tank and you're good to go! It seems like all the "fixes" are imperfect or downright dangerous to me so why bother? Maybe I am missing something?

mwoo said:
Hi Guys - I'm getting fed-up with the wet sumping on my Commando. The engine has been rebuilt and has only 500 miles on the clock. It runs beautifully and burns very little oil however it still wet sumps (I know, I know it shouldn't with a recond oil pump) but what the hell !!.
I don't like the idea of an external anti-drain valve but rather fancy an oil tap (with it's inherent dangers - I intend to cope with this). Have any of you fitted such a tap and where can I get suitable item(s). It needs to be fairly compact to be accessible. Any tips greatly appreciated.

Cheers
Click to expand...
 
In my youth I'd just start the beggar and hold it at 3000 until it stopped smoking, by then the tank level was up and I'd ride off. Nothing ever went wrong, never blew a seal, nothing.

Cash
 
I basically still do this! Am I doing something wrong :?:

I have never drained the sump to sort wet sumping, and whilst I am revving it,, it never smokes.

I'll probably blow the main bearing oil seal now for being so smug.
 
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