welding cast aluminum

[vanci]

i have a castt aluminum engine block from an artic cat snomobile(early 70's) that i need to weld some stock to.
i have no idea what type of Al it is made of. what are some common types of aluminum used for casting? what filler rod should i use. i plan on GTAW the block.

 

[bobber]

A lot of alum casting are A356. Not knowing what you've got I would try 4043, as it will give good results on a large number of alloys. Are you sure it's alum? It's common to find mag alloys on 2 Stroke Cycle engs . Find or make a bare spot and apply a mild acid like lemond juice if it's magnesium it'll turn black.