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thx138
12-02-2007, 12:30 PM
Are the turbo manifolds and the wastegate swingvalves cast iron or cast steel? Just curious as if they are cast steel then welding is fairly straightforward.

Directconnection
12-02-2007, 01:53 PM
cast iron

contraption22
12-02-2007, 04:14 PM
Judging by how they can be welded, I would say they are cast steel.

thx138
12-02-2007, 04:34 PM
Judging by how they can be welded, I would say they are cast steel.

That is what I was wondering. It sounds like they weld up allright so I was leaning towards steel for the swingvalves. Not sure how to tell.

johnl
12-04-2007, 11:30 PM
Aren't they a high nickel iron? Lots of em have been welded without issues. The problem, of course, is that as the steel of the weld shrinks it tears/separates some of the cast iron that is adjacent to the weld - creating a crack that you may not see. So, a series of stich welds with a nickel rod helps since the cracks are not continuous, instead they are like the stair step zig zag of the joints in a brick wall.

Best method I have heard of is - immediately after each stich, while it is still yellow and orange have an assistant use many many blows with a pick hammer to expand the metal adjacent to the bead and also to expand the bead itself - all to mechanically expand the metal while it is shrinking/cooling - sort of a race to expand it as it shrinks. Those multiple pick blows will minimize shrinkage cracking/separation of the parent casting from the weld. Pre-heating of the casting is assumed as that too reduces the amount of shrinkage.

t3rse
12-05-2007, 03:29 PM
called peening...

Clay
12-05-2007, 03:35 PM
as well as post heating, and nice, slow, controlled cooling.

jre97
12-08-2007, 02:52 AM
Do the spark test. Hit it lightly with a grinder if throws lots of sparks it's steel, if not many it's cast iron.