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su carbs on zetec
terryroberts - 7/5/09 at 05:03 PM

hi guys thinking about putting some su carbs on my 1.8 zetec... have to make up a manifold for bike carbs so why not make one for su's!!! what do you all think. mad idea or doable??

terry


clairetoo - 7/5/09 at 05:08 PM

Mad idea .


cliftyhanger - 7/5/09 at 05:11 PM

No point. The SU's ARE a very good carb, but I doubt putting twins or even quad carbs is going to be easy. Either dellortos or EFI I reckon


jacko - 7/5/09 at 05:23 PM

twin SU carbs/1
twin SU carbs/1

twin SU carbs/2
twin SU carbs/2

twin SU carbs/3
twin SU carbs/3


jacko - 7/5/09 at 05:43 PM

Yes use bike carbs i did after the SU's but the SU carbs were very good but took a bit of setting up to get right
carbs on manifold
carbs on manifold

Jacko


goodall - 7/5/09 at 05:50 PM

bike carbs and su's are the same principle as far as i can gather, just bike carbs are a perfected jap version, thats why get better mpg over webers, so why not, if have them lying about, its low-cost



[Edited on 7/5/09 by goodall]


The Baron - 7/5/09 at 06:45 PM

I am currently doing a Pinto to Zetec conversion project.

I am going to use my old DGAV carb, on a cross flow manifold, then........ I have purchased an adaptor plate to convert a cross flow mnifold to a zetec head (aparently its quite popular in the banger racing world)

so...... if you can get a su manifold for a cross flow, what you are proposing is quite possible.....

HTH,

Cheers,

B


jpindy3 - 7/5/09 at 07:10 PM

i got load of those plates,my mate who i work with races stock cars,i would stick with bike carbs


big_wasa - 7/5/09 at 08:53 PM

ive seen one on a stock car.

The guy just wedged a 90 deg bend into the mondeo manifold and stuck one big Su on the end of it.


DIY Si - 8/5/09 at 10:46 AM

Whilst bike carbs are better, if you have the SU's and the stuff to make a manifold, then it will be cheaper. Personally though, I'd go bike carbs as they are essentially like SU's but better.


ss1turbo - 8/5/09 at 06:01 PM

I fitted an SU onto a CVH using an RSTurbo MFI manifold - ran fine until it got hot then wouldn't restart! Think the manifold volume was too big....

Twin SU's don't work as well as they should due to the firing order (sucks twice from each carb, then leaves it alone for a whole revolution).

A Single would do the job better..and i've seen one done to a 1600 Pinto using a twin weber manifold with a cover plate over the top, and a hole cut in the back for the carb. Apparently made a little extra power, and was loads better on fuel economy!


britishtrident - 8/5/09 at 07:59 PM

Having spent a lot of my life working with single, twin and triple SUs and Stromberg CDs ---

I would say SU are very good very simple carbs (although depends a lot on the exact sub type eg HS series carbs are cheap rubbish especially the Waxstat type. ----- but my advice is don't even go there bolt on a Rover M16 or T16 Manifold and Microsquirt it.




[Edited on 8/5/09 by britishtrident]


DIY Si - 8/5/09 at 10:23 PM

quote:
Originally posted by ss1turbo

Twin SU's don't work as well as they should due to the firing order (sucks twice from each carb, then leaves it alone for a whole revolution).



Really? How does that work with a 1, 3, 2, 4 firing order that I thought the Zetec had? Or have I missed something?


ss1turbo - 9/5/09 at 07:44 AM

quote:
Originally posted by DIY Si
quote:
Originally posted by ss1turbo

Twin SU's don't work as well as they should due to the firing order (sucks twice from each carb, then leaves it alone for a whole revolution).



Really? How does that work with a 1, 3, 2, 4 firing order that I thought the Zetec had? Or have I missed something?


I thought it was 1,3,4,2 - so 3, then 4, foloowed by 2 then 1..Certainly is on a CVH.


jacko - 9/5/09 at 08:02 AM

As you can see in my other post i had su's on my pinto 1342 and they worked great


terryroberts - 9/5/09 at 12:19 PM

hi jacko what size carbs were you using? im thinking some of a dolomite sprint 1.75" should do i think. are good on sprints for upto 150bhp.


jacko - 9/5/09 at 04:12 PM

Hi mine were 1 3/4 su's but as you can see in the photos i now use zx9r bike carbs and the difference is unbelievable
if you are looking for speed / performance
bike carbs is the way to go in my opinion