Author Topic: anti syphon valve  (Read 2797 times)

Online Triton Thrasher

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Re: anti syphon valve
« Reply #15 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?

Offline kiwipom

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Re: anti syphon valve
« Reply #16 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   
A10.G.Flash(cafe racer)Honda 250 vtr. Yamaha Virago XV920.

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Re: anti syphon valve
« Reply #17 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
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
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Offline kiwipom

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Re: anti syphon valve
« Reply #18 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
A10.G.Flash(cafe racer)Honda 250 vtr. Yamaha Virago XV920.

War! what is it good for?Absolutely nothing, Edwin Star.
NewZealand

Online KiwiGF

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Re: anti syphon valve
« Reply #19 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*
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Offline ralph

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Re: anti syphon valve
« Reply #20 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.
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Online Triton Thrasher

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Re: anti syphon valve
« Reply #21 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.

Offline wardleybob

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Re: anti syphon valve
« Reply #22 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.

Offline olev

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Re: anti syphon valve
« Reply #23 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

Online Greybeard

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Re: anti syphon valve
« Reply #24 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?

Offline coater87

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Re: anti syphon valve
« Reply #25 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*
Central Wisconsin in the U.S.

Offline hdawson

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Re: anti syphon valve
« Reply #26 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.

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Re: anti syphon valve
« Reply #27 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*
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
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Offline bikerbob

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Re: anti syphon valve
« Reply #28 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.

Offline peter small

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Re: anti syphon valve
« Reply #29 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
BSA ROAD ROCKET 650cc 1954
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