Recently, we were asked to weld a General Motors V8 cast alloy rocker cover. Going by appearance, it seems to be of a die cast construction.
Due to some inlet manifold changes we were asked to remove the oil filler neck from one cover and weld it in position on the other cover.
When removed we had a hole of approx 65mm (2 1/2 in) diameter.
We cut a disc of 5052 aluminium to suit and welded it in position with TIG welding with 5356 filler rods. When cooling, cracking could be heard and on inspection the parent metal was found to be tearing away from the weld metal approx through the HAZ. After numerous tries we eventually got it sealed but it's not a job that I would be happy with myself.
Any thoughts by anyone on a procedure that may work on die cast aluminium? Perhaps a different alloy on the filler wire or the disc to be welded?
Looking forward to reading your comments.
Regards Andrew.