my friend has an old cast iron exhaust manifold that i was planning to mess around with soon. my original idea was to use it as a free flange, by cutting off the piping and welding my own. however, if i plan to make my pipes of the usual stainless steel, how will i attach the stainless to the iron flange? i don't think they can be welded together? is there a way around this? just wondering

btw, this is nothing urgent, just a fun/cheap/ghetto 240sx turbo mani to practice welding

 

I would try silicon bronze filler for that.

 

Honestly, I'd just buy a flange.

 

haha i know i COULD buy a flange, but i was trying to do this on the cheeep. if it comes to buying a flange, i'm not going to do it

 

to cheap to buy a flange but you're going to use "the usual stainless"? lol

 

You can buy exhaust flanges for like $20.

 

It probably makes perfect sense in his head.

 

lol you guysssss are missing the point! a $20 flange is $20 that i don't want to spend if there is a way around it! haha

 

an ebay flange will cost less than the filler rod you plan on buying.

 

no we are not missing the point. Even if it was cheaper, which it isn't, you would have fun times cutting those flanges off.

 

You're assuming the OP has a TIG.

 

which he doesn't. i got a MIG, reason #230728959 this a just-for-the-hell-of-it project. simple as this: if i can't reuse the cast iron flange, then i won't bother making a mani. it's more for fun than anything, which is why i'm trying to keep costs down

 

BUT if you can use the flange you are going to buy stainless pipe/tube? If you are trying to do this cheap then why stainless?

 

I used to have a 1999 Civic Si when I was in college that I built and installed a turbo kit on. I was broker than broke, everything I bought had to be on a credit card. So, jaysgottavtec, I hear what you're asking, I've been there.

I ended up taking a 1st-gen Eclipse 4G63 turbo manifold, cutting the head flange off, then welded it to a stock B-Series exhaust manifold flange. Cast-iron welded to cast-iron using mild steel MIG wire. It fit perfectly and let me run a big-16G turbo with the factory DSM O2 housing. And it cost me ~$25, total.

For what you intend on doing with it, go for it. Weld stainless pipe to the cast iron with stainless wire or mild pipe to the cast iron with mild wire. It may not be as strong, and it may not please the true fabricators, but it will meet your needs.

 

In the ghettoooo...

 

You're missing the point in that if he is going to be THAT ****ING CHEAP, why stainless instead of mild? And I'm not yelling at you. I'm yelling at the OP for being STUPID. If he doesn't care what happens and what it looks like, why not save money on all cheap materials? ****, mild piping and flange would be cheaper than the stainless piping alone.

 

you can weld it together... i hope you aren't going to try to file it or do any kind of machining to it, i figure you're not since its just a manifold... the weld will be hard as hell, which doesn't always mean strong

 

on a cold and grey chicago mornin'......

 

chill! haha, no you're right, mild is much cheaper. the reason i stated stainless was because i thought there was some extra in dad's garage. if there isn't enough extra stainless piping laying around, yes i'll use the less expensive mild steel for sure. until then, free stainless costs less than brand new mild steel

 

oh, and thanks for the input, fuhsm1!

 

cast expands this much |----| @ 1000f

stainless expands this much |------------| at 1000f

guess what will happen to the weld

 

exactly what i was going to say.

it will weld together fine but i betcha it cracks.


if you used some mild steel elbows it would be a lot more likely to last.

 

ok that's very helpful, thanks for the input guys

 

I've mig welded SS to cast years ago and it never failed, but that was a downpipe not a turbo manifold

 

ok, i got my friend's turbo, he got it off some old farm equipment of something, i dunno. big T6 twin scroll. it won't be able to spool worth anything, but we don't care. this is all for ***** and giggles, boosting until the KA blows up, then he'll swap in his built KA waiting in the garage with a more conservative boost setup