balance pipe on a set of kadron 40 carbs

[advinnie]

Hi all I have a 1699cc engine with a set of dual single chock kadron 40s. Now should j fit the balance pipe to link them together or not? What's the point of the balance pipe? I've never used one before on me empi or weber carbs. I've heard rumours that running without one increases performance is this true? Any information would be great cheers
Adam

[FJCamper]

Hi Adam,

One way to explain this is the balance pipe is a "communication line" between two otherwise isolated carbs so that they can sense by manifold pressure what the other side is doing and act together as a team.

Porsche 356's had a very similiar setup with twin single bbl Solexes back in the day, and VW has used crossover pipes on twin single bbl systems.

A crossover pipe really smooths out idle and up to midrange running.

Webers, which are very different technically, don't need a crossover.

If you run Kads, you should run a crossover pipe 9mm to 12mm inside diameter.

FJC

[Piledriver]

It helps to prevent idling on two cylinders, which is normal on dual singles otherwise
(due to the firing order/charge stealing)
As FJCamper noted, ITB setups (dual IDFs,Dells/IDAs/ITB based EFI) do not have the issue.

[advinnie]

Thanks for the replys. I think i will fit the balance pipe between the carbs.

[Marc]

Any dual 1-bbl setup needs the balance tube for street use, regardless of the brand name (Weber ICTs use one also). Note that the tube is subjected to full manifold vacuum which can collapse it when it's needed most, so if you use a hose it needs to be a stout one such as is used on power brake servos, or you can insert a screen-door spring inside a "soft" tube. Also, ensure that it's routed/secured to prevent it being drawn into the cooling fan.