[Mgs] MGB carb question

[David Councill]

I managed to get a picture of my 72B setup (engine/carbs from a 71BGT) 
that shows some relevant connections, that I have attached.

Now on the original picture, I noticed a number of issues which I will 
describe, starting from the engine and working out.

The intake manifold where you have looped in two ports - the rear port 
should have a nipple to connect a vacuum tube to the distributor. Other 
port should be blocked using a fastener.

On the engine side of the carbs, each carb should have a port (5/16") to 
pull in crankcase gasses. This uses rubber tubing and a plastic-Y piece 
to then connect to the crankcase side cover. Moss shows this here:

https://mossmotors.com/mgb-017-emission-system-controls-1970-74

The front linkage for the choke - your picture shows it near the rear 
carb, should be moved towards the front carb. That is because the choke 
cable will connect to Moss 372-340 bracket so that brass lever needs to 
be close to the bracket.

And finally, the float bowl covers - they are reversed in your picture. 
The three port cover is for the front carb. That is because the 70-71 Bs 
had a steel fuel line running towards the front of the car and the fuel 
line ran off of it. Then you have another port to run a fuel line 
between the two carbs. The overflow port should point out away from the 
engine/carb. The 70-71B would run lines from these two overflows back to 
a charcoal canister. Since you are using the engine/carbs in a MGA, you 
could use the earlier piping method used on the 62-67 MGB. These are 
steel tubing bent downwards so that the tubes divert petrol overflows to 
the ground. There is a bracket that holds them to the engine block, 
available from Moss.

Steel tuning is part 67 - https://mossmotors.com/mgb-020-hs4-carburetor

No longer available but you can make your own which is what I did on my 64B.

I am not sure where the MGA fuel line would be to connect to the SU 
carb. If it is not practical to use the 71-72 method of fuel routing, 
you could use the 62-67 method, replacing the two port float cover with 
a 2 port and use a T fitting on the fuel line:

https://mossmotors.com/mgb-028-fuel-pipes-and-lines-1962-70

Hope this helps.


David Councill

64 B, 72B, 67BGT

On 4/10/2023 8:50 AM, dave northrup wrote:
> These carbs are on an mgb engine in an mga.  We acquired this project 
> in kit form so I'm not sure what i have.
>
> I suspect these are mga carbs?
>
> And i don't know what to connect where.   The engine runs as is but 
> I'm sure I'm missing something.  (Little joke there).
>
> Can someone send me a picture and/or help me out?
>
>
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