im intrested in 2x 5-piece one(alloy inlet,stainless exhaust). dont u think it would be a better idea to get them the same thickness so that that torque up the same???

Good point - Dattoman, why not 12mm alloy for the inlet?

My guy cuts mild steel up to 12mm (maybe more i havnt asked) and SS and alu to like 5mm.

To get thicker alu he said i need to get it water cut.

I never looked into this further.

Obviously it depends on how powerful the machine they have.

why is everyone wanting 12mm. that is quite excessive for the a series. i would think 10mm would be more than enough concidering manifold builders that i know use 10mm for much bigger engines. if it was rotary putting out a stupid amount of heat that would be understandable.

I agree Picko 10mm plate would be fine for both.
I would be up for a set to suit oval port. I still have tyries old coupe a A12-14 bottom end and a oval port head and plan T28 with basic injection.

most places are helpful down here esp. if doing a bunch of them, ahum dont go to mitchell laser unless you want to pay stupid money and wait a month!

10mm will be fine for the 5 piece flange.... But I would highly suggest doing the one-piece out of 12mm...... the problem is not the heat the engine generates.... it's warping, while you manufacture the manifold...

on short 2-runner flanges it's not a problem, but the longer the flange get, the more it will warp as you weld it up....

i just rang a place here in perth and he said if he had to do nothing to the drawing (using the ones from here) then you are saving $45 straight away. i said i only wanted 2 and he said $40 and less for more quantities. why would anyone want a 1 piece when the intake is ali?

Exactly
Alloy for inlet steel for exhaust
Keep some temp out of the inlet
12mm for the exhaust so when its done you can mill it square.... hence the extra 2mm
Just a thought you see
Depends how good your welder is I guess

Maybe we should get a bit of a roll call going? I am keen on getting one as well.