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carbs on a 1.8 zetec silvertop
Fishface - 19/1/11 at 01:28 PM

i recently read somewhere that weber carbs dont run too well on a zetec and there is a flat spot. Ive had bike carbs on a pinto and loved them but am tempted to use webers this time.
Has anyone heard or experienced this?


whitestu - 19/1/11 at 02:10 PM

I've got ZX6R carbs on my Blacktop Zetec and they work great. They have a TPS and adjustable needles so are very adaptable. You can pick a set up for less than £40 on Ebay.

I respaced mine and fitted them using the rubbers from the bike so no manifold as such needed if you are doing things in a budget.

Webbers should work fine if set up properly but will cost a lot more.



Stu

[Edited on 19/1/11 by whitestu]


r1_pete - 19/1/11 at 02:19 PM

Bike carbs is the locost way, very effective and IMO just as good if not better than DCOE/DHLA.

But if you must have Webers then 45s with 5 progression holes are needed, the extra progression overcomes the flat spot.

I just took triple webers off my Jaguar, and returned to SU's which in principle are similar to bike carbs, the car is now far more tractable and drivable, plus I set them up with colourtunes and vac gauges, where as I spent a fortune getting the Webers set up by one of the UK's top Weber men.


prawnabie - 19/1/11 at 02:23 PM

I think the problem you are referring to is when using webers on a zetec. At light throttle the butterfly covers 1 or more of the progression holes just when the extra fuel is needed.


lewis - 19/1/11 at 03:01 PM

quote:
Originally posted by whitestu
I've got ZX6R carbs on my Blacktop Zetec and they work great. They have a TPS and adjustable needles so are very adaptable. You can pick a set up for less than £40 on Ebay.

I respaced mine and fitted them using the rubbers from the bike so no manifold as such needed if you are doing things in a budget.

Webbers should work fine if set up properly but will cost a lot more.



Stu

[Edited on 19/1/11 by whitestu]


I'm doing the same as you,any chance of some pics of how you have mounted the carbs if you are not using a conventional manifold pls cheers Lewis.


whitestu - 19/1/11 at 04:16 PM

Hi Lewis

There are some pics in my archive in the Zetec folder.

My solution was dead simple - basically I got some 5mm Aluminium plate cut to match the ports, ZX6R rubber manifolds and stud holes.

I then used some countersunk set screws through the back of the plate to attach bike card rubbers to the plate, cut a paper gasket and assembled the lot with planty of instant gasket.

The respaced carbs then just fit on using all the original clips plus a bit of flat bar to stabilise them.

I set the whole lot up with an AFR meter - main jets are 1.6mm.

The carbs are horizontal unlike on the bike but this doesn't affect their operation at all. I've done several track days and don't get any fuel starvation.

The respacing of the carbs is the tricky bit - needs access to someone who can turn some modified fuel fittings with 'O' ring grooves on a lathe that go between the carbs, but they aren't complicated.

The rest is just extending the throttle lugs and making some spacers out of aluminium tube.

Excluding the carb re-space it cost me less than £30 including the carbs.

If you need any measurements let me know.


inlet manifold
inlet manifold

Stu

[Edited on 19/1/11 by whitestu]

[Edited on 19/1/11 by whitestu]


lewis - 19/1/11 at 04:37 PM

Nice one stu thanks for that.


big_wasa - 19/1/11 at 06:17 PM

Ive had some 45's on my zetec. They where the five drilling zetec spec. They idled great and produced the top end but you just could not plant your foot down with out them bogging down.

Injection is the way forward.


whitestu - 19/1/11 at 07:28 PM

quote:

Injection is the way forward.



I'm not convinced - I quite fancy going efi but bike carbs are so easy and cheap, and seem to work at least as well as EFI what's the point on a fairly standard engine?