SU Carb Ports

HS carb 4-cylinder front:

HS carb 4-cylinder rear:

The front float chamber lid on North American emissions-controlled cars may have three ports like this - fuel in, fuel out to rear carb, and overflow: (SU Burlen)

The vent/overflow pipes. Short hose and clips 13 and 14 joining pipes 12 to the carb ports. Clip 16 (AHH7355) attaching the pipes to bracket 15 (AHH7382) with washers and nuts 17, 18 and 19. Bracket 15 (AHH7382) looks like it should attach to the left stud hole or blanking plate bolt of the moulding or aperture for the mechanical fuel pump, with the step clearing the right-hand stud and nut of the blanking plate. The Parts Catalogue indicates this arrangement ended at chassis number 258000 on export cars i.e. with the introduction of HIF carbs on those cars: Image from MGPartsUK

However the above drawing gives no clue whatsoever as to how the pipes are orientated on the car. The front pipe goes straight down and under the edge of the heat shield to meet up with the pipe from the rear carb, then both go through the mounting bracket on the engine mount (as here) or on the block bracket (as below):

The rear pipe goes down from the carb then turns forwards at a right-angle under the carb linkages to meet the rear pipe before going down through the bracket:

AHH7382 remanufactured by Ashley Hinton:

The mounting point for the plate (circled), which seems to be on all engines, largely obscured by the engine mount when in-situ:

Chrome bumper engine restraint bracket AHH7890 that fits round the left-hand engine mount (earlier cars had a mirror image round the right-hand mount as well). The two holes on the left go behind the bracket attached to the engine front plate, on the mount studs. The hole in the flange is a bit of a mystery as it is not shown in drawings, but is suitable to mount the carb vent/overflow pipes clip with a P-clip, nut and bolt and avoids getting the special bracket and messing under the engine mount:

Vent/overflow pipes attached to the chassis side of the mount as I'd seen on a concourse winner (also shows the countersunk bolts and stiff-nuts, arrowed) ...

... so moving the pipes on their hoses as the engine rocked. Also shows the mechanical fuel pump blanking plate (arrowed), used for mounting the original crankcase breather draught tube:

Restraint bracket mounted ...

... limiting the forward movement of the engine to about 1/4", with the carb pipes attached to it using the convenient hole so they move with the engine:

HIF carb 4-cylinder general view (paper bungs in the throats prior to removing the engine for a clutch change). The pipes leave the carbs pointing forwards and backwards, but the remainder of the routing is the same as for HSs:

HIF carb 4-cylinder front:

HIF carb 4-cylinder rear:

A general view of the V8 plumbing:

Detail of the left-hand V8 carb, mixture screw under the fuel inlet port:

Detail of the V8 right-hand carb:

V8 overflow pipe BHH1570 and tee-piece GWW401: (Brown & Gammons)

The pipe attaches to the upper right bell-housing bolt, with a short hose to the Tee-piece above, which has two hoses to the carbs, and a long hose leading down past the bell-housing. Because of that it needs to be fitted before the engine and gearbox are installed ... which probably explains why they are often missing, like Vee's. It's attached to the right-hand side of the bell-housing to be clear of the exhaust. Vee came to me without anything on the carb overflow ports which I wasn't happy with, but decided to put the Tee and long hose on that side as it seemed more logical. No supports in my case, but it's never become detached from anything: (British V8)