265 Hemi to efi

[heff0018]

I spoke with the fabricator and he advised that I would experience problems if a steel plate was welded to the cast iron manifold. Basically the welds would crack and keep cracking. He reckoned he would need to fabricate a new bottom section out of mandrel bends.

[slewinson]

I spoke with the fabricator and he advised that I would experience problems if a steel plate was welded to the cast iron manifold. Basically the welds would crack and keep cracking. He reckoned he would need to fabricate a new bottom section out of mandrel bends.

His approach will also flow better.

Simon

[Charlescrown]

I am surprised it cannot be welded. Being the inlet manifold it is not subject to the extreme hear from the exhaust. I have used a mig with steel wire to weld exhaust manifolds and they don't crack. I know it's not best practice and I understand the consequences but it works.

[heff0018]

Thanks, it can be welded I guess he is just covering his arse. Maybe I might give it a shot with my mig. I have a couple of manifolds lying around so no real loss if I stuff up. Another option could be using an aluminium version of the original manifold, I didn't ask him about welding cast aluminium to aluminium plate.

[vlad01]

cast alloy should be a hell of a lot easier.

[Holden202T]

yeah if you have an alloy one he'll be happier with that I reckon

[v6bucket]

There's no problems welding an alloy plate onto an alloy manifold.
A steel plate can be brazed onto a cast iron manifold, but don't weld with a MIG, it will eventually crack at the edge of the weld, due to different expansion rates & the cast will be crystallized at the weld edges.

[heff0018]

Thanks for the replies guys, that's good to know. Now I have a much cheaper option

[HQ355]

You ( fab man ) can weld cast alloy to alloy much easier, your original way can be done but it's not really ideal and not the best flowing, joining, etc etc way of doing it. Also if you go alloy you'll get a lighter set up which with the extra weight if the turbo and stuff will help equalize it out a bit.

[Charlescrown]

I was told years ago by a welder there is two types of cast iron grey and white and I think (might be wrong) the white cannot be welded.
I have attached a pic of my Pajero manifold I welded 15 years ago. It looks like it is just starting to crack in the weld though not the side where it joins the cast iron.

IMG_0883.JPG