20v Turbo Manifold Build

[olsonjus]

For the time being, I will be making headers out of heavy wall 304SS. At a later date I may try building a 321SS header. Really, you have to look at what your getting with 321. One have of 1% of titanium content. Your paying a ton of money for a very small amount of titanium that helps stabilize the metal at elevated temperatures.

The thing you have to keep in mind is that a properly welded 304SS header wont crack at elevated temperatures if welded properly.

Regards,
Justin

[Billman]

What material is the 1.4541 ?
Weldwire 1.4948 (Mangan).

Is it good for Headers?

[Billman]

ok i found out it is the 321 (WNr. 1.4541 (X6CrNiTi1810))

[olsonjus]

Billman, 321 SS generally requires the use of 347 SS filler rod to join 321 to 321.

Regards,
Justin

[olsonjus]

Justin

[Azman]

Looking good there matey.

[olsonjus]

[Micky B]

Here is a picture how we made it here. It s only cracked after 3 years of testing and dragracing and road use. It holds the weight of the down pipe and wastegate and turbo
gt 35R, egt sometimes more then 900 C on ALS.

[olsonjus]

Micky B, what wall thickness and grade material were you using?

Justin

[Micky B]

I use 304, 2mm wall. allways costum, everybody use different setup, in different car s2/s4 ........... I sell it 750 Usd....

[olsonjus]

The material I'm using is 0.109" wall thickness or 2.77mm wall thickness. I went to this heavy material to allow more weld area, thus a stronger joint. IMO a thick wall 304L manifold will not crack on the tube. It will fail on the weld as i have previously stated. This being the case, it is the weld area that needs more attention to detail than the material. The amount and or volume of filler in our welds is much more than a thin wall tube manifold....they are different types of welds or beads.

I can use material upto 0.145" or 3.68mm wall thickness if needed for my manifolds. That is the material pictured at the beginning of this thread. The only issue with using this runner material is that you must weld the joints in 2 passes to get full penetration without undercutting the topside of the weld. As you can see from this picture I'm still not perfect on my welds. I need to move quicker to get rid of the pink color. Ideally, the whole weld will have a golden color to it.



Do you have any closer pictures of your welds as they look rather gray, telling me the chromium has precipitated out of the stainless. Which makes it well, not stainless in the heat affected zone.

Regards,
Justin

[Micky B]

I don't have better pics of the welds.I'm only assebly the pipes and then bring it to a proffessional welder.The picture was taken few years ago, who weld it to me was't the best, I'm working a more prof guy now. But as you said before it should be golden coloured, it looks nice.
I've seen all F3000 exhaust at the 2005 F1 race on hungaroring, they didn't filled the pipes with gas!!! It looked like icicle...

[Jamo]

What did the finished manifold look like?

[Flat on my back]

Olsonjus,
Sweet welds, any chance of a picture of the TIG setup you're using?

[james_bufkin]

Justin,
One thing I did modify on the S1 manifold I have is to slice the flange to the head between the 1 and 5 cylinders. Since it has 4 studs per cylinder, thermal elongation of the flange would leak to excessive strain on the outer cylinders. (1 and 5). Cutting in strain relief so that the flange is 3 individual pieces should eliminate a great deal of that stress. The Lehmann also has slip joints on all 5 cylinders which I would highly recommend.

Id recommend have extra studs put in the head. 4 per cylinder.