Anti wet sumping valve with combined kill switch

[muskrat]

Yes Trevor, it all sounded like good sense. With my old race motor I did away with the timed breather and vented through the oil tank to atmosphere. Now what I've done is cut off the end of the timed breather to expose the hole. From where it exits the cases i have fitted a hose, valve and filter. This is now the inlet. The exhaust is from the rocker box to the oil tank then out to atmosphere via valve.
Cheers

[Tom23]

I fitted a BriTie anti-wetsumping valve, its simple to fit and as its a ball and spring you don't need to turn it on and off.
See ebay uk shop bsa unlimited, or email britie.motorcycle@virgin.net

[olev]

Muskrat,
With your Bunn breather, I see you vent through the rockers.
I would have thought there isn't much of a path from the crankcase to the rockers for relief.
Do you get much air coming out?
I've been interested in these for a while. (even posted the OBA article somewhere on this forum)
I was thinking of boring out the hole in the timing cover for extra relief.
Your trick of cutting the end off the timed breather sounds good as it shouldn't be needed with his valve. Can you post a pic showing how you set up the intake?
Interesting stuff, this
cheers

[muskrat]

G'day Olev,
                the two oil return holes in the ex valve wells seem to cope but would probably retard oil returning a little. I can hear the valve working. I didn't want to drill any holes in the cases, like the one on Rex's web page. So thought of using the original breather hole. I opened it up a tad and inserted a hose fitting and plumbed it to the filter and valve sitting near the genny. By cutting the timed breather thingy I am able to still use the cork to stop cam end float. All works well, I might re-position the filter higher up to get away from front wheel spray.
I knew I should have taken pictures. Doh !
Cheers

[lawnmowerman]

Thanks Groily. I have called AW Dove and he does a tap complete with a mag kill switch combined for £38 inc hose adapter for the engine side and a tail for the tank side which can be fitted to the solid pipe tail from the tank with a hose clamp or a compression adapter which I will probably go for. Price includes UK postage. I will order one and post some pics when it is fitted.
Thanks for the suggestion re the non return valve Tom. The PO has fitted one but having read a few previous threads about these valves there seems to be mixed opinion about their safety. I seem to remember reading somewhere that fitting one with a SRM pump invalidates warranty although I may be wrong - memory is not so good nowadays! I have decided to remove the one way valve for safety's sake and go for a manual tap.
G'day Muskrat. Like the sound of the Bunn breather kit - not quite sure how the crankcase breathes at present without spending some time looking at the engine books but it seems that there can be intermittent pressure build up with the timed breather from what I have read here and also build up of exhaust blowby. Probably a job for next winter though.
Thanks everybody else for the advice - this forum is absolutely superb.
Jim

[BSA_54A10]

The Bri-Tie anti wet sumping valve is just a larger version of what BSA fitted as standard.
So you are just duplicating what is already there.
Lesser marques do not have the spring valve fitted so either just trusted things to luck ( Notrun) or fitted a trust to memory tap ( Velo ).

[Triton Thrasher]

The Bri-Tie anti wet sumping valve is just a larger version of what BSA fitted as standard.

Are you sure? Don't BSAs have a valve downstream of the feed pump?  I've been wrong before, though.

a trust to memory tap ( Velo ).

Are you sure?  At least some velos have a ball valve on the tank outlet.

[BSA_54A10]

To the oil it is the same.
Ball bearing spring loaded on a seat in oil line or in crankcase behind pump.
Only real difference is the aftermarket item uses a bigger ball & the actual position.

And no I am not sure exactly which models of the lessser marques had what fitted or not fitted.
An associate with a Vello removed his factory fitted tap under the oil tank after he forgot to turn it on .
Not sure which model, if it is not a BSA then it is just "some other motorcycle " to me.

I do know that Commandos do not have any sort of valve as we used to run with the NOC for many years and I have seen many of them drain the sump before trying to start their bikes and got the whole sob story.
If you think a sump 1/2 full of oil makes an A10 hard to kick, try the same thing with a Commando !

[trevinoz]

Late Commandos have a check valve in the timing cover to stop wet sumping.
I can kick my Atlas with a full sump except in Winter when the oil gets a bit viscous!
  Trev.

[Triton Thrasher]

To the oil it is the same.
Ball bearing spring loaded on a seat in oil line or in crankcase behind pump.

There's a big difference between a valve before the pump and a valve after the pump.

And no I am not sure exactly which models of the lessser[sic] marques had what fitted or not fitted.

Fair enough.

[olev]

I've heard of a modification where the oil non return valve (spring & ball) is moved so it can be got at behind the pump, instead of from inside the cases. Does anyone know how its done?
I think the A65s did it this way.
cheers

[trevinoz]

Olev,
            This is possibly a SRM mod.
I gather the hole behind the pump is drilled through and a new spring and ball fitted.
Sounds easy enough if the engine is pulled down/
  Trev.

[bsa-bill]

Ah a mystery solved, I read an article in Real Classic where the guy remarked about the fitting the spring and ball behind the pump before fitting the pump and there was a picture as well that confirmed it, mind you the engine had an end feed conversion also.

[chaterlea25]

Hi All
I have an engine on the bench with this mod caried out I will take some pics tomorrow
and post them, its simple enough looking, I will measure how deep the hole is or how far the plug inside is away from the pump face,
My SR has this mod done since the end fed job was done, you have to be especially careful that fibres from the gasket do not interfere with the ball seating against the pump body, my SR was wet sumping away even with a new oilpump until I figured that out
No probs since though
Cheers
John O R

[chaterlea25]

Hi All
Some photos of the modified ball valve assembly
I am not sure if the same ball and spring are used or are they from an A65 ???? ????
The hole is drilled out to 8mm and the grub screw fitted from the inside is faced flat
The grub screw end face is just under 25mm from the oilpump face
hopefully the photos will explain!!
Cheers
John O R