SU Carb Refurbishment

[hkp57]

Hi
We decided to have the twin carbs rebuilt as I can't get them to hold a setting, think it is a problem with sucking in air along the butterfly spindles combined with general wear and tear.

Went to all the usual suspects that do more of a job than cleaning them and changing gaskets and the turn around time is stupid long like 18 weeks in some cases.

Any contacts in this area??

I am seriously considering though changing it to a single Weber carb such as the DGV twin choke down draft on a 1.8 Series B. Anybody got experience of this?

[stevejgreen]

Re: SU Carb Refurbishment

Sucarb.co.uk do an exchange service, not sure of the current details. They are not in Scotland but the other end of the country, Wiltshire!

For fitting alternative carbs check with the MGB world, there are many options but space in a Marlin engine bay is obviously limited.

[greyV8pete]

Re: SU Carb Refurbishment

Gower & Lee have been around for years and do a rebuild service on various makes including SU. I have used them for Weber parts and always found them very helpful. Maybe worth giving them a ring, or use the link below.

http://www.gowerlee.dircon.co.uk/rebuild.html

[hkp57]

Re: SU Carb Refurbishment

Steve
I have seen you say before about Marina axle limits for power, what is the assumed limits?

[dogoncrazy]

Re: SU Carb Refurbishment

Caterham used the marina axle in some of their 'sevens' and reckoned that 130 - 140bhp was about the limit I think. Too much torque will also kill it - think early Rover v8 which was about that bhp but a lot of torque

[lil_red_roadster]

Re: SU Carb Refurbishment

Driving style will have a significant bearing too...full-bore starts & kerbing the rear wheels round a track will kill it pretty quickly...broken half-shafts being a common occurence.
Touch wood, so far mine is standing up pretty well to significantly higher power levels...but then I only use it for fast A-B roads & not on a track.

[stevejgreen]

Re: SU Carb Refurbishment

All the above are pretty much spot on. Raceway made some beefed up half shafts with a different bearing arrangement, but only for the deep pocketed. The best solution for more power is to fit a Dolomite Sprint axle something that the Caterham racers were not allowed to do.

Simply swapping your carbs will not jump your power output by 30-40%. There is one roadster I know of with an efi 1.8 Zetec that still uses a standard Marina rear axle.

[hkp57]

Re: SU Carb Refurbishment

All the above are pretty much spot on. Raceway made some beefed up half shafts with a different bearing arrangement, but only for the deep pocketed. The best solution for more power is to fit a Dolomite Sprint axle something that the Caterham racers were not allowed to do.

Simply swapping your carbs will not jump your power output by 30-40%. There is one roadster I know of with an efi 1.8 Zetec that still uses a standard Marina rear axle.

I am considering an engine swap over the coming winter.

Two options now on the table are:-

1 = MX5 1.8 with its Auto box

2 = Zetec plus type 9

[stevejgreen]

Re: SU Carb Refurbishment

Both of those engines are around 115 Bhp in standard trim, the original B series around 95 Bhp.
The standard Marina axle, in good condition should handle that sort of power quite easily.
The biggest problem will be possible overheating certainly if you use the stock Chevette radiator that most roadsters were built with.

[lil_red_roadster]

Re: SU Carb Refurbishment

Don't underestimate the time, effort & cost involved of converting a very compact car designed for a simple, 8v carb-fed engine to 16v efi and a 5spd or auto box.
You will be chasing problems from one end of the car to the other and back again...
It's great when it eventually comes together but you look back and wonder where all the time & beer tokens disappeared to.

[philcoyle]

Re: SU Carb Refurbishment

On the subject of power, I have just been out in my Roadster 2ltr pinto engine having fitted my serviced injectors by www.Mr Injector.co.uk, so I have been previously driving around blissfully unaware how out of sorts my old motor was. The injectors are 30years old at least, but now it's like driving a different car and so so easy on the right foot, well worthwhile having the injectors serviced and returned with a complete log of each one. ear to ear grin factor.

[stevejgreen]

Re: SU Carb Refurbishment

Don't underestimate the time, effort & cost involved of converting a very compact car designed for a simple, 8v carb-fed engine to 16v efi and a 5spd or auto box.
You will be chasing problems from one end of the car to the other and back again...
It's great when it eventually comes together but you look back and wonder where all the time & beer tokens disappeared to.

The world of Kit Cars! One of the quickest ways of reducing your bank balance!

[andyf]

Re: SU Carb Refurbishment

If you like the look of the SUs why not try http://www.classicfuelinjection.co.uk

[hkp57]

Re: SU Carb Refurbishment

Does anyone have photos of a Zetec installed in a Roadster, cant find anything on it.

[lil_red_roadster]

Re: SU Carb Refurbishment

Try this...

http://www.marlinownersclub.com/forum/showthread.php?2271-Zetec-Inside-finally-finished!&highlight=zetec