gt37vgt

Last night I went to a friends work shop to weld up a 16v inlet manifold I moked up .
I was starting with about 4" of runner from a 2.5 S manifold when we tried to weld it went super brittle and would fall apart if you grabbed it with pliers .
so any eperiance posted would be great?
I was using the early 2.5 16v runner wich I've never seen done others tend to use S2 or 968 manifolds to start with .
should I have preheated the intire thing ??
we had no trouble melting it we turned the welder right down .
we tried 5% silican and 5% magnesium rods but the parent metal always crystalised and went bad .

while we're on the subject does anyone know of someone who has a measured drawing of the flange or were i can buy one

95ONE

pics?

2bridges

sorry never tried. Some aluminum compositions just don't weld well. what type of welder are you using? tig, or outfitted mig? I know from my own efforts mig can be a bit more challenging with aluminum.

TRP951

Im interested in this also since im working on making another flange for my intake manifold.

Chris Prack

Yes you must pre heat the part prior to welding. I assume you are Tig welding and aluminum rod should work ok.

Done this before with good results.

gt37vgt

so preheat then to about 300/350 C then keep some heat on it to stop it cooling to quick ?
it seemed there was about 4mm of glass like matial on the perimeter of the weld implying it has done this my cooling to fast as the heat would be tranfered in to the cold parent metal.
I'm tempted to throw it all in and make the manifold from stainles at home.
I have to track down this nocternal friend of mine to get him to open up another guys workshop were he keeps his AC tig to do the Alu . jobs but I'm up set for Stainles DC at home .
I'll get some pics up in the next couple of days

FRporscheman

I read somewhere that 968 intake manifolds were magnesium... is that true?

It gets brittle mostly because it cools too quickly - preheating would help get your welds going but keep them post heated too.

JET951

nope, only the 944 S manifold was magnisium. along with the S and S2 cam cover.

gt37vgt

"ta da" thanks sean so it is the magical antiweld that I've chosen .
so If i take to my S2 manifold things should come good

JET951

were you using the 944S manifold Adam? this makes a lot of sense now

333pg333

Yeah, and don't try and flog me that pos 'S' intake now that it's full of holes lol

95ONE

Nope, you're getting flogged. You ruined a Magnesium intake!!!!!!!!
; )

lart951

Cup car's intakes manifolds weren't they magnesium also?

fortysixandtwo

Yes, those were magnesium (Mg) also.

As well as the cam pully housings, on I think both, the S2 & 968.

Easy way to tell, is if the part has a beige paint on it, its Mg. Also the color of bare cast Mg is a very dark gray color.

TurboTim

Magnesium can be welded just as nicely as anthing else if it is don right.You have to be careful with Magnesium though becasue it can catch on fire and nobody can put it out till it burns itself out.