When to fit the Anti Drain Valve

Dear All,
I read the comments, all very interesting, about Anti Drain Valve on one topic now locked.
But I would ask you to explain to me what is the anti drain valve and why is appropriate to fit on.
Please use terms not too difficult to understand, unfortunately I can't translate everything easily.
Thanks.
Ciao

P.s.: wet sump is the same?

The Norton oil pump design can allow oil to pass - by gravity - from the tank to the sump - over time - if left standing, unused.
The valve provides a switchable barrier to prevent this occuring.

Just to answer the last part of your question:
Yes, it is the leakage past the oil pump gears that causes the oil to collect in the sump when the bike is not used for some time. That is what most Norton owners experience as "wet sumping" and it is not a serious problem although it can be annoying. It does mean that you must start the engine and run it for a minute or two before checking the level of oil in the tank so that you get a correct reading. Other than that, many owners simply live with it, while others prefer to drain the sump and put the oil back into the tank before starting the engine.
If the engine "wet sumps" while it is running, that is a different matter completely and it means that the pump is not returning the oil to the tank as it should. That would be a serious problem.

Regarding your question about reducing the clearances in the oil pump, the workshop manuals give instructions on how to do this. It is quite simple. However, some owners still get wet sumping even with NEW oil pumps. It seems to be a matter of luck. Leaving the engine with pistons at TDC is recommended to make wet sumping less likely.

Opinions vary about the fitting of anti drain valves. Some people say such a valve should NEVER be used. I don't have one and I don't intend to.

Cheers
Martin

Thanks, i understood it.
But, How do I know if my Commando's engine No. 1422 ... can have an anti-drain valve fitted inside the timing cover?.
I would like to revise well the oil pump, but inside there are only mechanical parts, how do I know which will work just fine.
I am grateful for the information that you can give me.
Ciao

pierodn said:

But, How do I know if my Commando's engine No. 1422 ... can have an anti-drain valve fitted inside the timing cover?.

Click to expand...

I think the ball valve modification is suitable for all Commando timing covers.
http://www.amr-of-tucson.com/nortech.html

http://atlanticgreen.com/norton.htm
http://atlanticgreen.com/images/oilpumpmod.gif

I can say that after installing my ball valve and safety ignition cut off switch, my bike has never been this dry on the bottom. I can actually run my hand over the bottom of the engine and come up clean. I can only attribute it to lack of oil collected in the sump while sitting. No more drips and oil all over the center and side stand. I think that was a bigger benefit than the bit of smoking it would do on start up.



I have heard the AMR ball solution is not always effective, no? Comments on that one too, please.

I think Nortonspeed is looking for a solution without the external valve and no electrical components though in the other thread (topic).

Dave
69S