13 replies to this topic

[Shiney005]

Apparently, Bob Forbes ran a pair of side draught SU's on the 308 in one of his L34's.  I am just wondering if anyone would have any info or pictures of them in situ? Or just a pic of a manifold would be great if there was an aftermarket one available back in the day. Nothing on Goggle.

[RallyRed]

Never heard of that...interesting

[V-SLR5000-P]

The MG B V8 had a pair of SUs on a hideous manifold which must have done nothing for breathing. The 308 would demand a couple of big jugs (3" is about as big as they came) could there have been more than two carbs? Jag and Austin Healey six cylinder engines ran three and triples were common on hot grey and red motors. Would be an interesting set up.

[AbsynthHatch]

Could you adapt the twin Weber setup to take 4 SU's

[Shiney005]

Bob said there were two carbys.   Twin 3" would have a huge CFM rating I would have thought.

The 4.6 Range Rover motor ran with two of them.

 

 Rover_4.6_V8_on_SU_carbs.jpg   238.59K   2 downloads

[AbsynthHatch]

If you wanted a unique induction set up, that would be the way to go.

[Dr Terry]

Is there such a thing as a 3-inch SU ?

 

Dr Terry

[Shiney005]

No. 2 inch was as large as they got, however with two of them you could potentially be up around 900 cfm.

[V-SLR5000-P]

Common SU imperial sizes found on Pommy cars include 1-1/8", 1-1/4", 1-1/2", 1-3/4", 1-7/8", and 2", although not every type (H, HD, HS, HIF) was offered in every size. There were also H models made in 2-1/4" and 2-1/2", now obsolete. Special purpose-built carburettors (Norman) were made as large as 3".

Edited by V-SLR5000-P, 29 December 2025 - 03:20 PM.

[rodomo]

Common SU imperial sizes found on Pommy cars include 1-1/8", 1-1/4", 1-1/2", 1-3/4", 1-7/8", and 2", although not every type (H, HD, HS, HIF) was offered in every size. There were also H models made in 2-1/4" and 2-1/2", now obsolete. Special purpose-built carburettors (Norman) were made as large as 3".

Great research! 

[Bruiser]

 IMG_1070.png   159.15K   3 downloads

[Shiney005]

Is SU a brand of is it a type of carb?

[S pack]

Is SU a brand of is it a type of carb?

SU is the brand name = Skinner Union. They are a constant depression (CD) type carburetor.

[V-SLR5000-P]

The SU carburettor company was purchased by Morris (owner also of the MG Car Company) around 1930 and later became part of the BMC and British Leyland group. A more widespread adoption of SU carburettors beyond British marques was inhibited by being part of the Morris conglometate rather than an independent entity.