welding aluminium and fuel reg questions

[cplux]

Is it ok to weld a normal piece of aluminium to an aluminium manifold?? need to mod the way the input flange on my supercharger is.

also does anyone know of any boost referenced fuel regulatorss for carby applications??

cheers

craig

[Fathillbilly]

is the manifold cast, extruded, fabricated, or what?, as if is cast it is realatively hard (expensive) to do. a decent TIG welder with the right stuff could do it no probs i think there is a guy on here Andrew W who might be able to help

[purefmx]

you're definately right about welding cast, its very porous and difficult to weld, talk to an engineering firm/workshop, fairly specialist stuff to be done right.

[cplux]

its cast, will be taking it to an engineering place to have it welded. just want to make the flange up myself, and have it welded on.

[ISUZUROVER]

It depends on the quality of the casting and the aluminium grade. Some has a high zinc content and is extremely difficult to weld.

I have cut and shut cast aluminium inlet manifolds and welded other (sheet) aluminium to it no problem. Most aluminium inlet manifolds are good quality and easy to weld.

I use a MIG with 1.2mm aluminium wire (not as neat as a TIG but does the job). The additional aluminium needs to be a grade that is easy to weld. I use marine grade (can't remember the number off hand).

[awill4x4]

Cplus, as Isuzurover said, castings with a high zinc content are a right bast**d to weld.
As a general rule, sand castings weld much more easily than pressure castings. Here in Melb, we TIG weld 99% of the casting repairs and I've found a filler wire of grade 4043 (5% silicon) seems to work best on castings. For normal sheet welding we use 5356 filler wire.
As far as plate is concerned my preference is for grade 5052, it is tougher than 5005 but is able to be bent through 90degrees which you can't do with grade 5083 which is harder again.
In your case try to find a specialist welding shop with lots of TIG welding experience. One that comes to mind in Sydney is Micks Metalcraft, they have a very good reputation for quality intercooler work there.
Regards Andrew.