xf weber on a fuego?

[renaulturbo]

Having already worked my cam and a port and polish on my fuego, i wanted to increase the fuel delivery. I was thinking of fitting a bigger weber carb off an xf falcon. This carb has same base dimensions so will bolt straight on the manifold. Some mods would be necessary including throttle linkages. Can anyone comment on this idea, would it increase performance? Would having unconnected vacuum hoses (there are heaps on the fuego weber) be a problem?

Cheers

 

[Stuey]

The first question would be whether all the extra work is necessary. A bigger carb. is generally only needed if the air flow has increased so much that the existing carb. cannot provide enough air - the corresponding fuel requirement can be catered for by jetting. So, if the existing carb. has some leeway here, then rejetting by a competent carb. shop with a dyno would do the trick. Note that this has to be done on the Falcon carb. anyway. Also, I'm pretty sure the Weber has removeable venturis as well, so these can be changed for bigger ones by the same specialist if required.

Be careful of thinking bigger is necessarily better, as you may find that the air velocity drops to such an extent that you have driveability problems and torque loss at lower revs.

Hopefully someone on here with Fuego experience can advise on whether or not the standard carb. is sufficient for you're modifications and the resultant airflow increases...

As for the vacuum hoses, well, they must do something...

Cheers

Stuey

 

[davemcbean]

The standard Weber fitted to Fuegos does not have removable venturis and is a little on the small side for any mildly modified 2 litre engine (although it's not too small by any means).

The Falcon Weber is not all that big either. It's actually very small for a 4.1 litre engine and not big at all for a 2 litre engine. The Falcon Weber has 34 mm throats with a 27mm venturi on the first throat and a 29mm venturi on the second throat. I have heard that they work well on Fuegos, but be careful because some Falcon Webers are known for tuning problems (there are atleast 2 variations of the Falcon Weber, XE or XF, I've been told the XF is the better one, but I'm not sure about this).

A Falcon Weber should only set you back about $60 (plus jets, about $6 each, 2mm or 2.1mm needle valve, and dyno tuning time), so it's probably worth a try.

Dave

 

[Frans]

I don't think you will gain anything because you will lose some of your air velocity which is very important. I would suggest that you first play around with jet sizes before you go to that extremes.

<font face="Verdana, Arial" size="2">Originally posted by renaulturbo:
Having already worked my cam and a port and polish on my fuego, i wanted to increase the fuel delivery. I was thinking of fitting a bigger weber carb off an xf falcon. This carb has same base dimensions so will bolt straight on the manifold. Some mods would be necessary including throttle linkages. Can anyone comment on this idea, would it increase performance? Would having unconnected vacuum hoses (there are heaps on the fuego weber) be a problem?

Cheers

 

[davemcbean]

As the first venturi of the Falcon Weber is only slightly larger than that of the Fuego Weber there shoudn't be a significant drop in air speed, drivability, etc. I've tried a similar increase in carburetor size on my 2 litre 504 and there was no loss in drivability or low end performance (but there was no noticeable increase either). That Fuego sounds more modified than my engine, so it is more likely to benefit from a larger carburetor than mine.

Dave