MG Car Repair: 78 mgb carb change, rubber hoses, manifold vacuum

Question
hi i have a 78 us spec,B. i want to put hif su's on it. i have an intake, exhaust manifold for older B's also complete exhaust for older B. what do i do with the side engine breather tube? run it to manifold vacuum? also i will need to run the carbs breathers to the carbon canister? any help or diagrams available for this procedure greatly appreciated. thanks joel

Answer

HIF Pipework Hi Joel
The breather on the side of the engine should be a metal pipe about 12mm diameter.  On each HIF4 carb there is a brass tube coming out at the side and pointing up about 45 degrees.  On the front carb, the pipe is to the left.  On the rear carb, the pipe is to the right.  No need to fit a carbon canister, you just need to connect  these 3 pipes together.  The MG Factory used 3 rubber hoses and a plastic Y piece.  See Moss parts manual, page 54, parts numbered 32 through 37.  The Y piece is part # 12G2134.   

The attached diagram should help you.