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MG MGB Technical - Float bowl overflow

Can anyone refer me to diagrams or pictures of the SU float bowl overflow arrangements. I assume there must be pipes to prevent overflowing fuel getting on to the exhaust manifold but none of my manuals/books have diagrams or photos that show them.
BTW this is on a 1963 Mk1

John
John Minchin

Mine leads via a small length of flexi to solid pipe , both then route together until they are south ( Im in UK !) of the manifold. They pass through a retaining clip en route .If you get stuck I can take some pics and e mail them. I have owned the car since the 60s so I'm sure this is original.
S Best

That's correct Steve. The flex tube is only a couple of inches long and used as a joiner to steel or copper pipes which are bent and shaped. I have used the bolts which fix the mechanical fuel pump blanking plate and routed the pipes through P clips attached to them cutting them off below the sump joint face.
Iain MacKintosh

Steve, Ian
Great - a photo or two would be a great help in getting the pipes shaped / routed properly - I'm trying for as much originality as possible.

I assume the pipe is same diameter as the float bowl outlet. The flexible tube - I guess fuel resistant hose??

Thanks for the advice
John
John Minchin

That's right John it is same diameter. Rubber tube about 2" long is OK. Have a look at Clausagers book and you will see the routing. If worst comes to worst I"ll take my air cleaners off and send you a photo.
Iain MacKIntosh

Hi John , would be pleased to e mail a couple of pics, are you on dial up ? If so how many bytes can you stand, I can cut them down to about 40 Kbyte but the resolution is not great then of course . The tubes in my car are either alloy or galavanised steel , and I will measure to OD for you .
S Best

Couldn't find enough detail in Clausager - in fact in some photos it looked like no overflow pipes fitted.
On more recent cars, pipes looked about the same as brake lines?

Steve - I can tolerate 40kb pictures OK


Thanks
John
John Minchin

John , I E mailed 4 pics to you . Should do the biz , but let me know if need any more. This was not too hard as the K+Ns give lots of room. OD is 1/4"
S Best

I've been wondering about my own overflow pipes... look like copper brake lines, about 15 centimetres long, each one curves from the top of the float and just points downwards...directly onto the manifold!

I have other things to worry about though, the junction between the floats and the bottom of each carb leak constantly, no matter how much I try and reset or tighten it. So I am looking for a kit. And the banjo-fittings from the inlet pipe to the float seem to loosen: the fibre-washers seem very hard to get a good fit with. After putting everything together yesterday after a 5 minute drive I checked under the hood with the motor running: petrol was literally spraying everywhere. Any tips, beyond being more careful with reassembly, to make things more "fuel-tight"?
Tom

Still mighty surprised the all-knowing Les Bengston hasn't weighed in on this one with his snore-worthy condescension.
Graeme Anderson

Thanks Steve for the pictures - I can sort the problem now

John
John Minchin

Tom,

if your float bowls leak the rubber grommet in the junction between the bowls and the carbs needs probably replacement. This grommet holds the the gas tube in palce and seals it form leaking. I had the same problem last year. Replacing the grommets solved my problem. No hard job to do.
Bert Otten

If others would find them useful I could post the pics on an MG site. Any recomendations ?
S Best

About flow bowls leaks, I have one more question. Recently in EMG was a shot of HIF4 whose overflow pipes were blocked by a nut. If I test that on my car it stalls
and dies . Anay idea, Who can help ?
Renou

One of the great things about the BBS is the free flow of information from any number of sources and especially from those with a great deal of knowledge on the subject of the cars or about specific areas of the cars. The latter group include Chris Betson, Paul Hunt, Steve S. and Les Bengston to name a just few that come immediately to mind. These people take the time to freely share their knowledge of the cars in an effort to help others in need of a boast in the upkeep of their cars. When there is a differing opinion or a disagreement, people have always been able to state that they disagree and present their differing opinion or information in a civilized and polite manner, even when the discussions become quite lively. For the most part, people frequenting the BBS who don't care for the style of a individual presenting opinions just ignore it or don't bother reading what they have to say and go on their way. For this reason, I believe that the cheap shot taken at Les Benson by the individual from Lances was uncalled for, unnecessary and totally inappropriate. Les, along with the others I have listed above freely gives of his time on the BBS to help any and everyone who needs his help or advice. Even though we have never met face to face, I consider Les a friend and a contemporary on maintaining our cars. So I would say that Mr. (or Ms.) Anderson should put a cork in it or take his or her comments to the Flame Wars section of the BBS where their type of comments are more appreciated. FWIW - Dave
David DuBois

Dave,

The best way to deal with such comments is simply to ignore them - nuff said?
Chris at Octarine Services

Renou - blocking the float chamber vents is *not* a good idea, they must be left open to the atmosphere, except when the anti-runon valve on North American spec cars comes into play. Blocking it prevents the fuel level rising in the float chamber and so prevents the float valve shutting off the supply, so the pump keeps pumping fuel straight up the jet and into the engine giving a grossly rich mixture and petrol in the oil. Date and page of the article to save me looking?

Paul Hunt

This thread was discussed between 04/11/2004 and 15/11/2004

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