A mate of mine has an MGB with knackered SU carbs.

Do we think it might be a reasonable option to fit a pair of bike carbs or are there other options?

Can't use 4 carbs as the inlet ports are siamesed like the A series.

Cheers

Mark

think bike carbs is a reasonable idea
can't remember what the mini ports were like, but wouldn't that cause a problem with bike carbs? might need some strange and clever manifold design?

Bike carbs are complicated SU,s. Both do the same job. The reason people are using bike carbs is that they come bolted together with there own linkage, SU carbs do not. However, there are manifolds and linkages for the Mini/SU combination easily available for you.
Use the SU. Infact I would recommend a single 1 3/4 SU carb for all road use. This carb will give enough BHP for most ROAD car use, and give very good MPG.

Rebuild kits for the SUs.

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Originally posted by atspeed racing
Bike carbs are complicated SU,s. Both do the same job. The reason people are using bike carbs is that they come bolted together with there own linkage, SU carbs do not. However, there are manifolds and linkages for the Mini/SU combination easily available for you.
Use the SU. Infact I would recommend a single 1 3/4 SU carb for all road use. This carb will give enough BHP for most ROAD car use, and give very good MPG.

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How about something off one of the big twins, they tend to be a larger choke size...

What is wrong with the SUs

the SU's are just worn out - pistons, spindles everything really

[Edited on 20/9/10 by mookaloid]

Use a single SU.
This will give you all the power and drivability you will need for a road car, even with a camshaft. We have fitted many of our customers with this setup and all are pleasantly suprised at the result. Even with a camshaft the "A" series will not pull peak power much beyond 6000/65000anyway.
Use the one from a Metro 1300 with a good inlet manifold and an LCB.
It works, I have proved it.

quote:

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Originally posted by atspeed racing
Use a single SU.
This will give you all the power and drivability you will need for a road car, even with a camshaft. We have fitted many of our customers with this setup and all are pleasantly suprised at the result. Even with a camshaft the "A" series will not pull peak power much beyond 6000/65000anyway.
Use the one from a Metro 1300 with a good inlet manifold and an LCB.
It works, I have proved it.

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Think I will delete all my replies to you.....sorry.....
For this set up, you would need a 2inch SU from a Jag to get any benefit, but the twin
1 1/2 would be a good set up for the 1800MGB. We have tried the 45DCOE on the MGB without much success. It would appear that the MGB prefers SU carbs.

How about using the bank of four bike carbs and doing a two into one manifold to bolt to the original manifold.Not sure whether there would be enough vacuum to pull through two carbs.

I think the bank of 4 carbs could work, at the end of the day the carb will only open to what it needs. Although it has 2 inlet ports it is still 1800cc.
Could work. But there already is a manifold made for the 1800 "B" series.

Mark
Bogg brothers do a manifold for mini's and use 2 r1 carbs they remove the 2 middle carbs from the 4
there may be a photo on there web
Graham

There were manifolds for the B series that used twin 40's i.e. Two chokes into one siamesed inlet port, no reason why you could not make an inlet manifold like that

Looking at my MGB performance book they used 1 weber 45 or 48 or split webers, there was also a 32/36 DGV conversion and if you google MGB manifold someone has done a twin throttle body conversion