The BSA A7-A10 Forum

Technical => A7 & A10 Engine => Topic started by: ralph on 08.01. 2017 20:03

Title: anti syphon valve
Post by: ralph on 08.01. 2017 20:03
Hi, I have after many years noticed a decrease in wet sumping time. I have an aftermarket valve fitted into the feed line at the rear of the c case (CA10). has anyone had experience of dismantling and overhauling one of these valves?

thanks
Title: Re: anti syphon valve
Post by: trevinoz on 08.01. 2017 20:06
I would dismantle it and smash it with a hammer so it couldn't be used again. Then go and get information about the results when the valve fails in the closed position.
Title: Re: anti syphon valve
Post by: ellis on 08.01. 2017 21:11
I fitted a SRM oil pump a few months ago as my A10 wet sumped badly if left for more than a couple of days. After I fitted the new pump it does not wet sump at all. An expensive item but well worth the money.   *good3*  * *good3*

ELLIS
Title: Re: anti syphon valve
Post by: muskrat on 09.01. 2017 08:40
G'day Ralph.
I'm with Trev 100%. I don't care how many or what type of fail safe mechanisms people use to remind them to turn it on, sooner or later it or they WILL fail.
1: Fix the cause. You might be lucky like Ellis and a new pump will fix it. If not split the cases and renew the ball & spring.
2: Fit a sump plate with a drain plug and drain the sump before starting. That's what I do with my incontinent A7 plunger (will drop the whole oil tank into the sump in 3 weeks *eek*).
Cheers
Title: Re: anti syphon valve
Post by: ralph on 09.01. 2017 09:14
Yes, I'm inclined to agree a new pump would be the way to go. Possibly the shorter wet sump time would correlate with normal wear in the pump clearances. I have to admit, when I built the engine 25 years ago, I wasn't even aware the valve was there! *red*

Title: Re: anti syphon valve
Post by: terryg on 09.01. 2017 13:31
Many swear by the SRM pumps but there has also been discussion here of refurbished pumps, if I remember rightly. Also, when I needed a fix SRM had no stock.

I had some success reducing leakage through the pump by cleaning up the inner face of the pump clamping plate, removing the wear caused by the pump gears. I believe worn gear spindles also contribute to leakage, which is more difficult to fix.
Title: Re: anti syphon valve
Post by: peter small on 09.01. 2017 17:17
I fitted a SRM pump and still wet sumps.
 i asked them when i bought it if it stopped wet sumping they said no,
Fair enough its better as the pumps new and wear is minimal.

They were honest. 
Title: Re: anti syphon valve
Post by: Dean on 09.01. 2017 17:35
I fitted an SRM oil pump to my wet sumping bitsa A10.....still wet sumps.

Many years ago I fitted an anti wet sumping valve to the Super Rocket. Stopped wet sumping.

Overall I would probably recommend either the orignal BSA solution (ie ride the bike every  day) or a sump with drain plug (the option I've gone for with the Bitsa)
Title: Re: anti syphon valve
Post by: RichardL on 09.01. 2017 18:21
The oil retaining ball and spring should have been replaced and the ball re-seated along with the pump change or, at least, at the next splitting of cases. Obviously, less work to replace the punp than the ball.

Richard L.
Title: Re: anti syphon valve
Post by: scotty on 09.01. 2017 20:45
I fitted SRM pump to my A10 for perceived better performance rather than to cure wet sumping.

I'd say that mine wet sumps less compared to my re built original pump but it does still wet sump.

I don't have any external anti drain valves fitted

Come to think of it all of my bikes wet sump  *eek*

Draining the sump with the drain plug is just part of the pre ride ritual for me

S
Title: Re: anti syphon valve
Post by: Topdad on 10.01. 2017 12:03
My two penny worth, having fitted a non return valve and ever so nearly blowing my motor because the ball stuck   *angry*,mid season ,bike used regularly , working fine previous ride to absolutely not a drop coming back next time out  *dunno* I'd never fit another and am happy to drain the oil pre ride .
Title: Re: anti syphon valve
Post by: kiwipom on 11.01. 2017 08:46
Hi guys, has anyone ever thought about the possibility of installing an AAV (air admittance valve) 'Bunn' type on the oil tank breather. This would create a vacuum in the tank and would not allow oil to flow 'wet sump' until the pump created a suction thus restoring oil pressure when engine is started, cheers
Title: Re: anti syphon valve
Post by: muskrat on 11.01. 2017 09:02
G'day kiwipom.
That's a thought from left field. As a matter of fact my A10 Cafe breaths into the oil tank and then to atmosphere through a Bunn. Not exactly the same as your idea but she never wet sumps. Pitty the Bunn Breather is no longer available.
Cheers
Title: Re: anti syphon valve
Post by: kiwipom on 11.01. 2017 09:09
Hi guys/ Musky, just a thought and throwing it out there for comments, I thought you would like it. Now waiting for someone to rubbish it, cheers
Title: Re: anti syphon valve
Post by: ralph on 11.01. 2017 17:32
Hi guys, has anyone ever thought about the possibility of installing an AAV (air admittance valve) 'Bunn' type on the oil tank breather. This would create a vacuum in the tank and would not allow oil to flow 'wet sump' until the pump created a suction thus restoring oil pressure when engine is started, cheers

Amazing. for the past two days Ive had a cap head stuffed into the breather pipe based on the same thinking. come home from work today and it looks to have stopped the drip from the crank plug. I have also a rubber O ring that seals the filler cap which should help. The pipe is poking out the drive side under the seat, so unlikely to forget to unplug. Having said that, I'm not sure it would be totally destructive if one did forget. I'm basing this on there being a build up of pressure in the tank - given the scavenge side of the pump is of greater capacity than the feed. So, Kiwipom, i'm off to study your Bunn valve. Ill keep you all posted as to if I find a completely dry drip tray tomorrow after work.
Title: Re: anti syphon valve
Post by: Triton Thrasher on 11.01. 2017 18:00
Hi guys, has anyone ever thought about the possibility of installing an AAV (air admittance valve) 'Bunn' type on the oil tank breather. This would create a vacuum in the tank and would not allow oil to flow 'wet sump' until the pump created a suction thus restoring oil pressure when engine is started, cheers

What happens when that sticks shut?
Title: Re: anti syphon valve
Post by: kiwipom on 11.01. 2017 20:04
hi guys/TT, thought of that but a`fail open` valve could be fitted where valve is held shut by a correct tension spring but would `fail safe` if the spring weakened. Other design aav,s that fail safe could be used,cheers   
Title: Re: anti syphon valve
Post by: muskrat on 11.01. 2017 20:08
G'day Ralph.
I wouldn't block it off solid. What about fitting a duckbill ( http://duckbillcheckvalve.com.au/ ).
Cheers
Title: Re: anti syphon valve
Post by: kiwipom on 11.01. 2017 21:43
Hi guys, yeah Musky that would work if you could get one that would open at the correct pressure, also duckbill valves are generally used to open on outward force or fluid suction as on boats as opposed to inward suction however it seems like the simplest option, cheers
Title: Re: anti syphon valve
Post by: KiwiGF on 12.01. 2017 07:01
Is there any danger of a vacuum in the tank forming, that is enough to stop oil getting to the inlet of the pump with this plan ? *pull hair out* *pull hair out*
Title: Re: anti syphon valve
Post by: ralph on 12.01. 2017 18:11
G'day Ralph.
I wouldn't block it off solid. What about fitting a duckbill ( http://duckbillcheckvalve.com.au/ ).
Cheers


Hi guys, yeah Musky that would work if you could get one that would open at the correct pressure, also duckbill valves are generally used to open on outward force or fluid suction as on boats as opposed to inward suction however it seems like the simplest option, cheers


I do like the idea of the duck valve. Cheap and failsafe. It made me think of the outlet on a whoopee cushion. I can picture it now - "heres ralph ont beeza - the old fart".
Anyway, the drip tray has some in it this evening but a lot less than yesterday. Plus, ive been testing this on only half a tank of oil. IE a lot mor air space. With the oil level where it should be = less air space and less oil needs to drain to create ness'y vacuum. I love it.

These may not be set too high methinks    http://www.ebay.co.uk/itm/0-AVENT-BREAST-PUMP-SPARE-PART-WHITE-DUCK-BILL-VALVES-4-VALVE-PK-/182326929861?hash=item2a738829c5:g:wxsAAOSwXeJYDZWF
Just needs a bit of research.
Title: Re: anti syphon valve
Post by: Triton Thrasher on 12.01. 2017 18:15
Is there any danger of a vacuum in the tank forming, that is enough to stop oil getting to the inlet of the pump with this plan ? *pull hair out* *pull hair out*

Yes, I expect so.
Title: Re: anti syphon valve
Post by: wardleybob on 12.01. 2017 19:49
I fix A7 A10 engines as a part of my business and 50% of them have anti syphon valves fitted and they cause a lot of problems. Even if they work you get a reduced fĺow.
Title: Re: anti syphon valve
Post by: olev on 13.01. 2017 13:25
Here's one from left field.
Convert the engine to wet sump.
Fit an external sump and extend the pickup.
Fit a full flow filter across the old oil tank flow and return lines.
No more wet sumping.
oil is filtered on the supply line.
Low centre of gravity.
cheers
Title: Re: anti syphon valve
Post by: Greybeard on 13.01. 2017 16:04
Convert the engine to wet sump.
But unless you modified the cases the crankshaft would be running in the oil. Would that be ok?
Title: Re: anti syphon valve
Post by: coater87 on 13.01. 2017 16:22
 With only 6 inches of ground clearance, I dont see where their would be room for an external sump.

 You would have to mount it to the four small holes currently holding the sump plate on, which would not be strong enough given the vibration. Or mount it to the four small holes AND the frame, which would be way less than optimal (constant leaking because of different harmonics, if not cracking from metal fatigue.)

 I just cannot envision where a external sump would be even possible, or practical. *conf*
Title: Re: anti syphon valve
Post by: hdawson on 21.01. 2017 09:02
At the risk of being thrown off the forum and with much respect to the more experienced members ( *respect*) I cannot help giving my 2 cents worth.
Since fitting a (manual) inline ball valve to the BSA oil feed was so successful, I also fitted one to my Matchless with similar results.
Placing a reminder on my throttle grip seems foolproof. I use a dedicated colourful rag.
After a ride I leave the valve open overnight so I have some residual oil in the sump for a priming start up next time.

Cheers all, Hadrian.
Title: Re: anti syphon valve
Post by: muskrat on 21.01. 2017 09:41
OK I can understand all sorts of electro/mechanical safety cut outs but a colourful rag takes the cake.
 *bash* *lol*
Title: Re: anti syphon valve
Post by: bikerbob on 21.01. 2017 11:09
These things are always going to be controversial I have an A7 that wet sumps can only be left for no more than a week without draining the sump which has a drain fitted, the A65 on the other hand can stand all winter without wet sumping. I would never use an anti wet sump syphon because some people have had serious problems with them  as to the ball valve this is something I have considered but the problem is of course remembering to open it even with the afore mentioned electrical and manual and  coloured rag safeguards, I think I wiil stick to the drain valve until such times as the engine needs a strip down then I will look at trying to cure the problem if the A65 does not wet sump then the A7 should be fixable.
Title: Re: anti syphon valve
Post by: peter small on 21.01. 2017 21:02
Why not leave the bike with the pistons at top dead centre this would help wet sumping. oil way in journals upper most.


Pete
Title: Re: anti syphon valve
Post by: metalflake11 on 21.01. 2017 22:26
Why not leave the bike with the pistons at top dead centre this would help wet sumping. oil way in journals upper most.


Pete

There's definitely something in that. I did some work on a B33 a year or so ago. Wet sumped like a gud 'un it did, anyway I ended up having the use of it for a few months, and I found it stopped doing it altogether if I left it at T.D.C.

Different animal altogether, I know, but certainly worth a try.
Title: Re: anti syphon valve
Post by: duTch on 22.01. 2017 01:32
Quote
Why not leave the bike with the pistons at top dead centre this would help wet sumping. oil way in journals upper most.

  I've considered that ^^, but as I'm lucky I don't have wetsump issues, never pursued it; having said that, I also considered that ALL the oil in the crank gallery would drain back to the T/S Main bush and further, so would need to be primed some before startup.

 On the other hand, I also considered what would happen leaving it at BDC, or half way between but as I don't have an issue never bothered.

 I reckon if it'll be parked up long enough to wetsump, best option is to start up periodically (not ideal unless going somewhere), or even better drain the oil tank into a container and re-add it before riding(maybe even through a filter).

 I have to say, I'm getting fairly bored with this crap subject, even if some of the ideas are 'entertaining'


Title: Re: anti syphon valve
Post by: muskrat on 22.01. 2017 19:00
Yep, I've said it over and over. If it wet sumps either fix it (split cases and renew the ball & spring) or fit a sump plate with a drain plug and spend a few minutes draining the sump before startup.
Pete, I prefer to leave it at bottom so the crank is full for next startup.
Cheers
Title: Re: anti syphon valve
Post by: kiwipom on 22.01. 2017 19:12
hi guys, good on ya Dutch, I get amused by posts `prattling` on about Spark Plugs but whatever spins your wheels, cheers 
Title: Re: anti syphon valve
Post by: ralph on 01.04. 2017 07:57
Just an update for those who got interested.

Did an oil and filter change, got rid of the AS valve, and have fitted this   

http://www.ebay.co.uk/itm/121392722933?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

to the oil tank vent pipe. No probs to associate with excess oil tank pressure apparent after 150 mile run last sunday. Oil tank had warmed up after 20 miles suggesting good circulation. Have been laying up with pistons at TDC. Will get back with how much and how fast oil gets to sump.
Title: Re: anti syphon valve
Post by: duTch on 01.04. 2017 09:58

Quote
....to the oil tank vent pipe.....
yeah-might do it's stuff, but but I think it's a different issue (kettle of fish *conf2*) I'll stand by on the outcome ...

 
Quote
I did some work on a B33 a year or so ago. Wet sumped like a gud 'un it did

 
Quote
Different animal altogether,.............

 probably not so relevant, but; don't the singles run a roller big-end?? which would not affect whether or not to leave it at tdc/bdc/45bdc/57/46/21 a/b/t/bdc...or who cares?? *conf* *smile* *bash*
Title: Re: anti syphon valve
Post by: bikerbob on 01.04. 2017 14:09
Looking at that anti syphon valve I can see the theory behind it, you are in effect making the oil tank airtight assuming of course that the filler cap is air tight. So if air cannot get in then oil cannot leak out or at least  it will slow it down considerably. Not being any kind of expert on these things I would worry if it would affect the oil circulation when the bike is running. I have a similar thing fitted to my tropical fish tank air pump it allows air through to the air stone but when the pump is off it prevents water being syphoned back into the pump.
Title: Re: anti syphon valve
Post by: duTch on 01.04. 2017 19:42

 I guess it's the same principle as (from memory) Orabanda Richards'  'flap-valve' (whatever it's called), I run my engine and tank breather pipes into a vented plastic juice bottle below, and happy to say they don't catch much  *eek*, so also use a drip try *pull hair out*
Title: Re: anti syphon valve
Post by: muskrat on 01.04. 2017 20:43
G'day Ralph & all.
My thinking of the n r valve is that when the bike is started cold and the pump scavenges the oil level in the tank rises a little. This creates a slight pressure that the n r valve expels. Then the oil warms up and due to expansion (oil and air in tank) pressure increases and the n R valve expels it. Now when we take our girl to the flicks and come back to the now cold bike a few hours later, there could be a slight vacuum in the tank. Would this restrict flow to the feed side of the pump  *????*
Your thoughts on this?
Cheers
Title: Re: anti syphon valve
Post by: ellis on 01.04. 2017 21:24
Mmmmm

I think I will refrain from all types of none return valves, and just drain the sump if the bikes stood longer than a couple of months.
Much safer way to protect my precious engine.   *smile*

ELLIS


Title: Re: anti syphon valve
Post by: ralph on 01.04. 2017 22:18
G'day Ralph & all.
 Now when we take our girl to the flicks and come back to the now cold bike a few hours later, there could be a slight vacuum in the tank. Would this restrict flow to the feed side of the pump  *????*


Good day to yourself/ves , Quite right by my way of thinking, a theoretical vacuum would be present, but with the return side of the pump being of more volume than the feed, the vacuum would be lost on startup. It would be interesting to attach a pressure guage t't tank. I have a spare cap to drill...........
I need a girl....maybe my life's a vacuum......
Title: Re: anti syphon valve
Post by: bsa-bill on 02.04. 2017 10:01
Quote
I have to say, I'm getting fairly bored with this crap subject,

Fair enough but it's always new to someone
Title: Re: anti syphon valve
Post by: muskrat on 02.04. 2017 10:11
Ralph, you do have a valid point.Just waiting for Trevor to set us all straight.
Cheers
Title: Re: anti syphon valve
Post by: RichardL on 02.04. 2017 15:00
Oil tank had warmed up after 20 miles suggesting good circulation. Have been laying up with pistons at TDC. Will get back with how much and how fast oil gets to sump.

I assume that this test for a warm tank is not replacing watching for flow from the return tube in the tank just after startup. I try to practice this religiously.  It seems to me that the riskiest time is immediately after startup. So, if you've got the cap off to look in the tank, you are assuring one atmosphere present at that time. After that, with the valve, you start to depend on outflow and inflow maintaining a balance at approximately one atmosphere (under the circumstances described by Muskrat).

Richard L.
Title: Re: anti syphon valve
Post by: duTch on 02.04. 2017 15:09

Quote
I assume that this test for a warm tank is not replacing watching for flow from the return tube in the tank just after startup. I try to practice this religiously.  It seems to me that the riskiest time is immediately after startup. So, if you've got the cap off to look in the tank, you are assuring one atmosphere present at that time. After that, with the valve, you start to depend on outflow and inflow maintaining a balance at approximately one atmosphere (under the circumstances described by Muskrat).

 I tink i overdid the midication *conf2* *eek*
Title: Re: anti syphon valve
Post by: kiwipom on 02.04. 2017 23:09
Hi guys, not meaning to `Annoy` Dutch, I will continue the thread. Thinking on this subject. If the feed to the rockers were to be sourced from elsewhere and blocking off the oil tank breather, would an equal in and out pressure be created thus creating a pressurized oil system, experts opinion needed as this is only a bored persons thought, cheers   
Title: Re: anti syphon valve
Post by: worntorn on 03.04. 2017 04:11
This was my solution for wet sumping. This bike had a new oil pump in an all new engine  but liked to wetsump in about a week. Fortunately the SR takes about 2 or 3 months to wet sump, so it won't need an antisump valve.
With this one the ignition key is needed to shut the oil off. Once off, the key is captive in the valve until flow is turned on again. No wires or switches to fail. It works.
Glen

media/20150721_214936-1_zps7sgfcwjg.jpg.html](http://i1233.photobucket.com/albums/ff397/worntorn1/th_20150721_214936-1_zps7sgfcwjg.jpg)[/URL]
(http://i1233.photobucket.com/albums/ff397/worntorn1/th_20150721_214858_zpslicayryv.jpg) (http://s1233.photobucket.com/user/worntorn1/media/20150721_214858_zpslicayryv.jpg.html)
Title: Re: anti syphon valve
Post by: Tomcat on 03.04. 2017 08:39
That's a good setup WT.  *smile*
 I know this is a BSA forum but WE ARE gunna need more piccs of that Vincent
Title: Re: anti syphon valve
Post by: Zander on 03.04. 2017 10:27
And to think, that in the 50's we just used to buy a bike, put petrol and oil in and ride it, with the occasional necessary odd job carried out as and when! Ignorance is (was) bliss *eek*
Title: Re: anti syphon valve
Post by: Greybeard on 03.04. 2017 12:37
...I know this is a BSA forum but WE ARE gunna need more piccs of that Vincent
Just have a wander through his PhotoBucket gallery.
Title: Re: anti syphon valve
Post by: kiwipom on 03.04. 2017 23:23
yes Greybeard very impressive work he should be giving us advice, cheers
Title: Re: anti syphon valve
Post by: Black Sheep on 05.04. 2017 22:08
Velocettes have an anti-sumping valve as standard and they still wet sump - perhaps not as much as they might do without it. So if your Velo has been standing a while, you still have to drain the crankcases or you will never start it. My assorted BSAs all wet sump to a degree. Can't say it troubles me.
Title: Re: anti syphon valve
Post by: muskrat on 06.04. 2017 11:13
The simple answer is to ride'm often or take a minute to drain the sump (think of it as a constant oil change ((unless you put it back in the tank like me))

G'day BS, how about an intro in Pictures, Stories & Intros. We're a nosy bunch *lol*
Cheers
Title: Re: anti syphon valve
Post by: worntorn on 06.04. 2017 13:36
I think the problem today for most of us is too many motorcycles and not enough good motorcycling weather. We've had a particularly long and crappy winter here in Vancouver  with dismal rainy weather starting last November and still going strong in April!
I have managed to ride the BSA a couple of times and that was enough to keep the oil in the tank. It's amazing how well it holds the oil in the tank.

Glen
Title: Re: anti syphon valve
Post by: ralph on 16.05. 2017 22:54
well just to give some feedback re my fitting of a one way valve on the oil tank breather, to hold the oil in the tank. Not really a success until a significant mount of oil has left the tank, only then creating anything of a vacuum to hold the rest back.


thanks to all for their help, advice and consideration - I did however, as always, enjoy the messing about process *smiley4*