BSA Owners' Club Workshop Discussions

The BSA Workshop => Singles => Topic started by: Crazy Mike on 06 May, 2020, 17:21

Title: B40 - Wet Sumping - Oil tank tap
Post by: Crazy Mike on 06 May, 2020, 17:21
Hi All

After researching this Wet Sumping issue, I find this is more common and affects many older British Bikes, including BSA's. In an effort to minimise this on my 1961 B40, I decided to fit a valve tap which hopefully will reduce it's incontinence, save a bit of oil and keep my garage floor clean'ish.

I couldn't find too many pictures from others who have done the same so I attached 2 pictures showing the finished modification. I want to keep my B40 as near to it's original spec so I was in two minds about this but as it's turned out, it looks ok for me.

There are 2 parts I used. The valve itself is a 1/4" BSP male to 1/4" BSP female full flow ball valve and the second part is a 1/4"BSP female hose tail (8mm) which fits nicely to the flexible oil supply hose of 5/16" id. Total cost about £8 off t'internet. If anyone is considering this mod, I am happy to give details of supplier and part no's etc if you PM me.

As a reminder to me to make sure I switch the tap on before starting the bike, I remove the ignition key and hang this from the new tap (providing I remember !)

Hope this may help anyone considering this mod.

Cheers !
Title: Re: B40 - Wet Sumping - Oil tank tap
Post by: berniej on 06 May, 2020, 18:15
Hi Colin,

I've fitted something similar - although in the hose line so a bit lower than yours.
So far I haven't forgotten to open it but there's always that worry about next time....

One thing I thought of but haven't yet done is to turn the body of the valve so that the operating arm sticks out sideways and to then extend or replace the operating lever with something a bit longer.

This would still fold down out of the way when in the 'open' position but would stick out and interfere with the swing of the kickstart lever when in the 'closed' position - or at least be very obvious to the eye as you prepare to start up....

I've also recently installed an automatic 'on-demand' valve on my M21 - I swear that wet sumps more oil than there is in the tank!
This is just a spring-loaded valve which opens under suction. Velocette installed them as standard screwed into the the tank where your valve is. (I prefer to get it as close to the pump as possible to reduce the amount of air in the line after an oil change which might make priming more difficult).

It works perfectly for me but I always check the return flow to the tank after starting just in case.

There are those who would consider it too much of a risk and maybe that's right for an engine with white-metal big ends that will be wrecked even after a moment's oil starvation but with the roller big-end engines I'm relaxed enough to use it - at least I can't forget to turn it on and there are already enough other pre-flight checks with an M21 that have to be gone through before applying the boot!!

Cheers,
Bernie


Title: Re: B40 - Wet Sumping - Oil tank tap
Post by: Blackthou on 06 May, 2020, 20:54
Nice neat job. I've thought of it too. Also thought about the check valve berniej mentioned. What opening pressure did you choose berniej?

I suppose we never forget to turn the petrol on, just need to condition ourselves to "Petrol on, Oil on"
Title: Re: B40 - Wet Sumping - Oil tank tap
Post by: Mike Farmer on 07 May, 2020, 08:57
 :) :) :)

I put an "on demand" valve on my A50. No probs and no wet sump.

Mike 8) 8) 8)
Title: Re: B40 - Wet Sumping - Oil tank tap
Post by: Phil C on 07 May, 2020, 09:18
That's a neat job, Crazy Mike. A bit more subtle than mine perhaps (see pic.) But I guess the bright colour of mine might help me remember to turn it on. That and the penant on a string I hang between it and the choke lever when I park the bike in the garage.  Phil
Title: Re: B40 - Wet Sumping - Oil tank tap
Post by: Blackthou on 07 May, 2020, 09:25
Re on demand, NRVs or check valves, what opening pressure are you all going for?
Title: Re: B40 - Wet Sumping - Oil tank tap
Post by: berniej on 07 May, 2020, 10:13
I haven't been able to find the receipt for my automatic valve and can't remember where I bought it from but I don't remember any pressure values being specified.

As it only has to resist the pressure exerted by the head of oil in the tank I would imagine that they are all set to be very low so that the slightest drop in pressure will cause it to open.
I think I remember sucking through mine to test before fitting it!

Cheers,
Bernie
Title: Re: B40 - Wet Sumping - Oil tank tap
Post by: Greenfield on 07 May, 2020, 11:04
I fitted automatic anti wet sumping valves to both my A50 and B40. I fitted one first of all to the A50 which used to dump most of the oil in the sump if not ridden every day. I got fed up with draining it off before starting. They work perfectly and its impossible to run without turning on. Worth considering.
Title: Re: B40 - Wet Sumping - Oil tank tap
Post by: Mike40M on 07 May, 2020, 12:18
My 1967 B40 Mk1 wet sumps about a litre in two weeks. There is no obvious place for a valve as it has high level exhaust. Any ideas? So at present I use a https://bprtrading.co.uk/bluespot-3pc-flexible-hose-clamp-set-clamping-pliers-radiator-brake-fuel-pipe-1761-p.asp under the tank outlet. Can't kickstart it without removing the hose plier.
The 1970 B44 VS don't seem to wetsump much, so I have no immediate need for a valve. Anyone fitted a valve on one?
Title: Re: B40 - Wet Sumping - Oil tank tap
Post by: Blackthou on 07 May, 2020, 20:46
I'm probaybl over thinking it as when we use them at work we either specify them in a few psi up to 1000s of bar.  Looking on the internet just now i'm sure a simple commercial one would do. I've changed the spring and ball in sumps before and they have no major resistance.