MGB: Plumbing HS4 carbs

I'm mounting a pair of HS4 carbs that came with my 67 motor and am a little confuzzled as to what is supposed to plumb where.

Here are the fuel bowls as they are mounted:

Front Carb:


Rear carb:


Which goes where? Are these bowl lids on backwards? They came this way.

Also I am using the carbon canister, which one goes to that?

Thansk

OK I did some searching and I think I have it figured out...

On the front carb, the two top nipples are for fuel feed, feeds into one from the pump and out to the rear carb. Am I right in thinking it doesn't matter which one is in and which one is out to the rear carb?

I believe the lower nipples are the carb overflow/vent to the carbon canister. Right?

First pic the brass nipple on the right is inlet, the nipple on the left feeds rear. and yes on the overflows

Scott,

Here's a couple of pics of the HS4's on my '67 engine (don't mind the mess). They're not quite the same as your's but it may give you some ideas.

Jimmy will be able to tell you for sure what you've got.

These may help. I attached the C canister tubing to be under the carbs.

Great, thanks guys.

Michael, what the advantage to using the vacuum ports on the carbs for the PCV instead of the stock PCV valve thingy?

On my 1971 the carb overflow/vent to the carbon canister line runs over the manifold. The rear carb airfilter can has a bracket that a pipe strap mounts to, to hold the vent line in place.

I have a '71, but I bought AUD405's from Jimmy. They were from the 1970 models that used ported vacuum, so that is how I installed them. When Jeff S. worked on my dizzy, I specified ported vacuum.

Mike

There are a kazillion different designs when it comes to SU float lids, different stylr vents and different angles of fule supply tubes. I think you fiquired it out that the three tube lids are designed to bring the fuel into that carbs, then tranfer fule to the oter carb, and the third tube is a vent then on a two tube lid, on is always fuel supply and the other a vent. If you remover the lids, and insepcet them is easy enough to fiquire what tube is for waht and with a flaot and neelde valve in palce it east enough to blow into the fule supply tube and move the flaot up and down by hand which open and shutrs the needle valae and confirm what is fuel supply or not. There a bunch of way you can confiquire fule dievery on on a car like ours whether it the way the facotry did it or not, you can make the rear carb the tranfer carb or the front, whichever suits you, some folks follow the book and do it just like the factory , other redesign thier set up to suit them, on race cae we normally use tow two tube float lids and bring fule to each carb separately, there's many ways to skin this cat. Hope this helps.

Hi Scott, here is my 67B with HS4 135s.

My 1967 GT is the exact same as Lee's, and I'm guessing that is stock routing for a 67 (I'm not much of a stock historian), which is two, tow tube lids ( two tube lid = one fuel supply tube and one vent tube) coming from the rear teeing off to the rear carb, then continuing to the front carb. Later cars use one three tube lid, and one two tube lid, mostly from what I seen on the crossing over form the front carb, but there again this cat can be skinned many ways.

I once built a set of carbs for a guy, that he had sent me his actual cores, so his same float lids were used, a three tube lid on the front carb, and a two tube lid on the rear carb. he called me all upset, said the needle and seats were stick open on the front float lid, demanded I sent him another lid, with a good needle and seat to him pronto, because he needed to get his car on the road, I did so, then he called back with the same gripe. Turns out he was plumbing the carbs differently than he took them off, teeing the supply line and feed each carb without a cross over hose, which ment the tree tube lid had one fuel supply tube open to the air and everytime he would turn the fuel pump on fuel was sraying everywhere. Finally after I got him to send me a picture of his carb plumbing and I fiquired out his mistake, he changed his hoses around and all was fine.

Fuel supply hose is done a little differently fom early to later MGBs, so Scott, you could use the tree tube lid on the rear carbs, crossever to the fornt, and use what you have and accomplish the same thing as Lee and my car is doing.

Just realized that I am missing the choke cable holder (btw what a bass ackwards way to set THAT up). Can I just make something out of steel or is it special.

Looks like it bolts to the carb front plate?

Nevermind, I figured it out.