Well what a disastrous rebuild this has been

[stu.andrews]

Hi bikerboy
I take your comments. Nothing much can go wrong, but it's just one more tiny thing that can, & I'm all for eliminating anything that can cause a problem. I was shown the anti sumping valve that was in my machine when the previous owner had his disaster. It was actually quite corroded. Shouldn't have been, being in oil, but it was & it seized shut, possibly after standing a long time of non use. Which ever way you go- best of luck.

Stu

[chaterlea25]

HI All
Bikerboy,
 What goes wrong is this !!!!!
The standard BSA oil pumps leak through the end joints, spindle and even through the porus alloy while the bike is standing idle
Then the pump is not oil filled it cannot easily suck through the anti sumping valve
BAD NEWS!!!!
The original design means the pump is always oil filled

HTH
John

[bikerboy]

John

I can see your point but I don't see as the wet sumping valve will affect that one way or another. If all the oil drains from the pump then even emptying the sump and starting the engine will leave a little amount of time before the pump is refilled. Having the valve will have the same affect I would assume

[chaterlea25]

HI
the valve stops the pump priming!

John

[trevinoz]

Then the engine blows up!

[bikerboy]

Sorry but I cant agree with that.

When I fitted mine it was wet sumping badly so I dropped the sump and drained it overnight. I also took the oil lines off to fit the valve the next day. This obviously means there was no oil in the line and none in the pump or line when the valve was fitted and the engine was started. The feed line at the bottom of the engine points downwards as well so that had to be empty.

When I started it the oil circulated after a few seconds without me having to prime the pump or do anything else to the engine. All I did was half fill the empty oil tank with oil nothing else.

[muskrat]

The "feed" line in the bottom of the motor is the scavenge pipe and it has a ball in it to try to keep that side of the pump primed.
Your convinced your mod will work and I say best of British luck to you. I honestly hope your valve does work in the long term with no problems.
We just don't want to see another topic with a similar heading.
Cheers

[mayes]

I had same when i rebuilt my Triton many years ago,all seemed right spark fuel etc checked everything in desperation had a mate tow me after heating plugs up fired and run from then on always started well sods law? John

[chaterlea25]

HI Bikerboy,
""

Sorry but I cant agree with that.
When I fitted mine it was wet sumping badly so I dropped the sump and drained it overnight

""

With all due respects, I would be surprised if the pump body emptied overnight???
If the bike sits for several days /weeks/ months then the pump will be empty and then will NOT suck through the ASV
Your opinion, many others very expensive consequences !! including my friends Vincent
My brothers A10 threw a rod out of bed due to a porus pump body, the old pumps in my opinion, experience is the weak link
My own SR will stand for months without wet sumping, It  has a new pump and the A65 type mod with the ball behind the pump, no shortage of oil flow around the ball.
The customer engines I build all have this set up done to them, money well spent!!!

Regards
John

[bikerboy]

With all due respects, I would be surprised if the pump body emptied overnight???
----------------------------------------------------------------------------------------

I said I drained the sump overnight. The bike had stood for a fortnight and the oil tank had emptied virtually completely. I then drained the sump overnight and left the pipes off. I was actually concerned that the pump would need priming but all I did was fit the valve, refit the feed pipe and fill the tank with oil.

Yes I would prefer to not have a valve but I am not prepared to strip the engine down completely again to mess about with that ball and spring when it has taken me over a year to get the thing on the road. For the minute I will rely on the valve and when my other projects are finished I will strip this one back down for a couple of reasons and then I will sort out the spring but until then I will just monitor the oil circulation every time I start it up.

As for the A65 mod I was giving this serious consideration until an article on here last week which disputes that is such a good idea after all.

[RichardL]

This has been a very long thread and one of the most discussed topics, so, I hope I haven't missed or forgotten someone else mentioning my idea. Specifically, once the valve is closed, emptying of the feed line and pump seems quite unlikely due to having no vent, absent a leak in the line. Of course, I'm neither endorsing nor poo pooing the valve, but just thinking about the circumstances.

Richrd L.

[chaterlea25]

HI
Richard,
In an ideal World you would be correct, however my experience is that the pumps are not oil or air tight and so will empty over time, the asv will prevent further oil reaching the pump

Bikerboy,
Draining the sump has no effect on the feed side of the pump which is the critical side

End of topic as far as I'm concerned 

John

[RichardL]

Please, John, let me just continue this study for a bit more.

Would an empty pump matter, in terms of priming, if the line is full?

This issue with the porous metal in pump has me puzzled and I'd like to learn more about it. Can you steer me to any articles?

In my last post I think I should have said, "Due to continuing ignorance, I am neither endorsing nor poo pooing the valve."

Richard L.

[chaterlea25]

HI Richard,
The collective wisdom and probably bitter experience suggests that the empty pump will not suck through the asv
if the oilway/pipe between the asv and pump are air filled
If the oilway/pipe to the pump is full of oil then the pump will work

I have as I said personal experience of the autopsy on my Brothers SR after the blow up
I have set up a standard pump on an engine with the oil feed connected and washed off the outside of the pump with brake cleaner, come back later and wipe a tissue on the surface and it will be oily
on a bad pump you may even see the oil appearing on the surface

I had some more thoughts on the asv things, they were probably introduced over 25 years ago and the bikes would have been + -30 years old ?
The pumps are now much older and the material degenerates over time are in a worse state than when the asvs were originally tested
(my 2 cents worth)

I know from work on the single cylinder BSA's that the pumps are equally crap
If a BSA single has been left idle for a long while its well known that the pump drive may strip if the engine is turned over or started,
Best to remove the pump and make sure its free to turn before recommissioning
I first had a problem with a BSA single pump in 1983, which was free to turn when removed and tightened when bolted up,
The single pump is a sandwich with the layers additionally held by the holding in screws, in my case the alloy of the pump was compressing when the screws were tightened

On a current customer (budget) A10 engine rebuild, I sent the oil pump to SRM for reconditioning and testing
It still failed on their test rig after reconditioning !!!

When I served my time in the seventies it was standard practice to fit a new oil pump on every car engine rebuild
Good practice then and now!!!!

John

[RichardL]

John,

Thanks for taking the time in creating the interesting read. So many cost bullets to bite during rebuilding that I'm wondering if I'll survive the lead poisoning.

Richard L.