I Need M42 exhaust manifold information!

[bmwman91]

Just wondering what type of stainles steel it is made from. I would guess just 304/304L, but could it be 316/316L or 321? Does anyone know (I figure you guys deal with custom header jobs more than anyone, so hopefully you know!)? Thanks.

I bought a manifold from a wrecked E30 M42 & want to go through & re-weld all of the seams on it (as well as my currently used one). The things are very prone to cracking, & I cannot have it leaking for 2 reasons:
1) It sounds bad
2) The MegaSquirt WILL be going in in the next 1 1/2 months...with a Wide-Band O2. Any errors in my readings will prevent me from getting the most benefit from it. Once the MS is in, the stage is set for me to "contribute" in this part of BF.c

[ZeroG]

Just wondering what type of stainles steel it is made from. I would guess just 304/304L, but could it be 316/316L or 321? Does anyone know (I figure you guys deal with custom header jobs more than anyone, so hopefully you know!)? Thanks.

I bought a manifold from a wrecked E30 M42 & want to go through & re-weld all of the seams on it (as well as my currently used one). The things are very prone to cracking, & I cannot have it leaking for 2 reasons:
1) It sounds bad
2) The MegaSquirt WILL be going in in the next 1 1/2 months...with a Wide-Band O2. Any errors in my readings will prevent me from getting the most benefit from it. Once the MS is in, the stage is set for me to "contribute" in this part of BF.c
The OEM Mainfold is cast iron not SS.

-Chad

[943184dr]

i have one off a e36 m42, and that i know is not cast iron. i dont knwo about being stainless but its definatly not cast iron. as for the e30 m42 manifolds i have only seen those in pictures so i couldn't say for sure. but i'm still leaning towards something other than cast iron.

Tom

[cuansbmw318is]

e36 m42 is forged so...

[TheNeek]

i have one off a e36 m42, and that i know is not cast iron. i dont knwo about being stainless but its definatly not cast iron. as for the e30 m42 manifolds i have only seen those in pictures so i couldn't say for sure. but i'm still leaning towards something other than cast iron.

Tom

The e30 M42 exhaust manifold is not cast iron. I cut off the end and made it single exit welding it with a MIG. That would be hard to do on cast iron.

You can make it out in this pic:

http://www.bimmerboys.com/silverstreak/M42/exhaustnopaint.jpg

[943184dr]

The e30 M42 exhaust manifold is not cast iron. I cut off the end and made it single exit welding it with a MIG. That would be hard to do on cast iron.

You can make it out in this pic:

http://www.bimmerboys.com/silverstreak/M42/exhaustnopaint.jpg


Dude, that thing looks exactly like the E36 manfiold. but why do that to the manifold when you are turbocharging your car?

Tom

[toyosupr]

Id guess its steel, just use steel rod.

take a magnet and it it sticks its steel if not its stainless.. most of the time lol

and if stainless just use 308 rod

[TheNeek]

Dude, that thing looks exactly like the E36 manfiold. but why do that to the manifold when you are turbocharging your car?

Tom

This is when I was swapping the M42 into the E21. OLD picture.

[bmwman91]

Thanks guys. Cast iron manifold...lol this isnt an M20 (well, some M20's anyway).

[zorba]

Thanks guys. Cast iron manifold...lol this isnt an M20 (well, some M20's anyway).

(This is RocknE30 on my dads username)

Do you plan on turbocharging the 318is soon? I am just curious because I am looking for more information and pics on custom manifolds for a top mount setup. I pm'd a member who has a daily driver 318is that is turbocharged, so hopefully that will yield something :)

[needle332rur]

I'm doing the same thing right now. I just bought a OEM manifold and soon i am going to rework it into a turbo mani. The only thing to look out for is i think (not sure) the reason for the lack of welds on the stock mani is to alow flex from being hot and cold all the time.

Also are you doing this to a e30 or e36?

Last are you planning on runningthe turbo high of low?