6 replies to this topic

[BJDavis]

I've purchased the "original shape of petrol feed pipe for twin HS" carbs as fitted to all the Coopers" that's sold on Minispares: http://tinyurl.com/aegxelg I wanted to convert from the current rubber hose connections to the solid pipe and braided hose combination. However, now that I look at it . . .I'm not sure how the connections are made. I'm either a complete idiot (possible!) or I've got a mismatched combination of carburetor and connections.

Here's my engine bay as it stands now. A metal line from the tank comes up on the right of the picture where a rubber hose connects it to a fuel filter, then a line from the filter connects to the top of the SU float bowl. That's where my question arises.

 SU Carburetor Fuel Lines.jpg   84K   81 downloads

The new metal connection pipe has three connections. The two that link the SUs together are a given . . . but where does the third connect to? Am I missing a connecting part?

 Fuel Line SU HS4.jpg   87.76K   67 downloads

I've looked at tons of images online, searched the forum, and gone through my Haynes books and just can't SEE the same comination that I've got. Any suggestions?

[A-Cell]

The intent of the metal link pipe is to connect to carbs that only have one inlet on the flat bowls, so the metal pipe connects the 2 carbs together and the 'third' connection is the inlet from the fuel filter in your case. To use the metal pipe you will need to change the top of the flat chamber to a single inlet one.

[BJDavis]

The intent of the metal link pipe is to connect to carbs that only have one inlet on the flat bowls, so the metal pipe connects the 2 carbs together and the 'third' connection is the inlet from the fuel filter in your case. To use the metal pipe you will need to change the top of the flat chamber to a single inlet one.

Ahhhhh . . . .That makes perfect sense now. Thanks for solving my mystery.

Do you think there's a simple (clean) way to simply block off the inlet where the filtered line is currently connected? Or would it be best to find a replacement float bowl lid.

[Dan]

Why are you making the change? What you have now will work fine. If it's in the name of originality then you should change the float bowl lids. Your current lids also have the overflow outlet pipes, although they aren't connected to an overflow system. The original lids used with your new pipe would have simply had the plated overflow outlet rather than the overflow pipe outlet. What you have now is superior in many ways to the brazed pipe section.

[BJDavis]

Snipped: Why are you making the change? What you have now will work fine. If it's in the name of originality then you should change the float bowl lids.

Dan - I was looking for more of an original and tidier look. You've got me re-thinking again (wink).

I'm not sure I've seen any detailed images of the "overflow system". I'll have to do a search. THANKS to all for the suggestions.

Edit: Hey . . Look what I found now that I know what to look for: http://www.theminifo...ing-pipe-issue/

Edited by BJDavis, 24 February 2013 - 07:52 PM.

[A-Cell]

Only overflow piped up I have seen was on single carb. Just a rubber joiner and a piece of metal pipe to direct the overflow down past the exhaust manifold onto the road. The float chamber lid without has a hole covered with a domed passivated zinc plated piece covering it to prevent dirt entering.
I too like the look of the link pipe and the braided flex pipes. Also as you clip the metal pipe to the throttle cable abutment bracket it makes a tidier installation than using a rubber flexible pipe to link the 2 carbs.
Maybe you cold source some 'ordinary' float chamber lids ( they are just standard HS ones), or modify yours. Remove the extra fuel feed pipe and make a plug that fits flush and bond it in with araldite.

[Dan]

No I don't think multi carb Minis ever got an overflow connection, those float lids were for other models and to be honest probably for California and other territories requiring fuel vapour emission controls. There are about 30 different HS float lid layouts. If you aren't going for originality you can choose any lid to sort out the plumbing however you want.