brabham

[dave hc692]

Will brabham carbs fit on a 1256cc engine and would it make a lot of difference than staying standard, thanks dave

[Fred Dukes]

They will fit - should be able to set up with the original needles but I am no expert - seems an expensive way forward - would have thought twin choke weber would be best option

[Retro morgs]

I fitted the Brabham twin carb set up to a 1256 before,There is very little if any performance gain. Looks good but a bit pricey for what it does,a Weber set up would def be a better option

[Johnboy HB]

If fitting to a HC, I believe you'll have to fabricate a throttle linkage as it's different to a HB

[1972nail]

Yes, the Brabham carbs will fit with a modified linkage, and a Weber DCD is a better option. But in my opinion, and that of Mr Blydenstien in 1976, a single bigger carb is the best option on a standard engine. WBB started fitting a 175CD Stromberg as a performance mod to the 1256 Chevette from 1976 instead of the Weber DCD. He also fitted a DCOE to the 1256, but only with far more extensive internal engine work.

After seeing the 175 CD mod in the DTV SportPart manual I fitted a 1 3/4" SU from a 1300 Marina on a modified and opened out Viva manifold to a mates Chevette.

I was running a DCD on my Viva at the time and his Chevette was every bit as fast, more econimical and nicer to drive.

[Fred Dukes]

What needle was fitted to the CD175 then David?

[rattlyolddt]

What needle was fitted to the CD175 then David?

Also intrigued, as I have a Janspeed manifold in the shelf. I would quite like to try a 1 3/4 SU or CD next year.

[1972nail]

What needle was fitted to the CD175 then David?

Don't know, that was a Blydenstien secret..... The SU I fitted retained the standard Marina 1275cc needle, spring and jet setup. I can't remember if I originally fitted the Marina airbox but my mate modified the standard Chevette one to fit.

We choose the SU over a 175 CD as we guessed that if we used a 1275 Marina one then the needle etc would be pretty close to being right. There weren't many 1300cc cars with a 175CD so it would probably be a poor match without trial an error modification.

[rattlyolddt]

See that was my logic too; I had a MG metro engine in my mini which was good for 70 ish hp. The janspeed is the equivalent of my old mini LCB manifold, so figured I'd go down that route rather than faff with guessing the jetting on a cd175 from an 1800 or whatever.

Does anyone know if the bolt pattern for the engine side of a cd175 is the same as a HIF 44 SU?

I already have a CD175 adaptor for the cd150 manifold

[1972nail]

40 years and my memory is clouded on the fitment of the SU but I did open out the manifold throat and did some mods to the carb. The HIF44 is a 4 bolt fitment and so is the CD Stromberg (or is it diagonal 2 bolt?) so maybe it wasn't too hard.