7.3 headers....

Hotrodtractor · Oct 5, 2012

OSCS said:
Yes it did..

Perhaps if they gave you a center to center distance on the exhaust ports you could infer enough info to make it happen - but NO you do not have enough information on that drawing to build a flange. You have a flange port diameter, the center to center of a typical bolt spacing (assuming they are symmetrical about the port), and an overall length which depends heavily on how much material you want around the bolt holes.

powerstrokenstang · Oct 5, 2012

A 5/8" flange or more would be nice. I had a flange twist to the point it wouldn seal.

OSCS · Oct 5, 2012

Hotrodtractor said:
Perhaps if they gave you a center to center distance on the exhaust ports you could infer enough info to make it happen - but NO you do not have enough information on that drawing to build a flange. You have a flange port diameter, the center to center of a typical bolt spacing (assuming they are symmetrical about the port), and an overall length which depends heavily on how much material you want around the bolt holes.

Your correct I am missing one measurement to complete the flange. I could pull it off the spare manifolds I have lying around

farm boy · Oct 5, 2012

OSCS said:
Your correct I am missing one measurement to complete the flange. I could pull it off the spare manifolds I have lying around

Missing more than one. But yea, you could take it off of a spare manifold.

OSCS · Oct 5, 2012

So why do header makers go with stainless steel if it continues to fail? What is a better material to use? And what would be the max temperatures they would be suseptable to on a truck making 500-700 rwhp and short burst egts seeing 13-2000? I know most steels start to change there composition around 2k. Are these manifolds seeing those kinds of temps?

DBQLSC · Oct 5, 2012

Had to reply. Stainless is fine to make a manifold out of. 304L stainless is a good comprimise between strength and affordability. 321 is ideal but expensive. Jesse warrens manifolds have seen extreme heat and pressures and they are holding up just fine. It all comes down to the welds and material thickness. It seems as though some people go with a thick flange and then use thinner tube. It you make the tubes thicker they become structural and are less prone to cracking and warping. Stainless also requires special considerations to be welded correctlly in a high heat/ pressure application. Full pen./ 100% fusion is were its at.

farm boy · Oct 5, 2012

DBQLSC said:
Had to reply. Stainless is fine to make a manifold out of. 304L stainless is a good comprimise between strength and affordability. 321 is ideal but expensive. Jesse warrens manifolds have seen extreme heat and pressures and they are holding up just fine. It all comes down to the welds and material thickness. It seems as though some people go with a thick flange and then use thinner tube. It you make the tubes thicker they become structural and are less prone to cracking and warping. Stainless also requires special considerations to be welded correctlly in a high heat/ pressure application. Full pen./ 100% fusion is were its at.

:whs:

Our shop builds vessel internals. 321 is where its at. Most all process internals are made out of 321. 304 is junk material for us.

Carbon content has alot to do with withstanding heat FYI. Alot of our customers specify .04% Carbon Content. Higher heat rating.

There is always Inconel... LOL

DBQLSC · Oct 5, 2012

Or hastelloy$$$$$ I build biogas compression systems so everything has to be stainless, or is disappears in a matter of weeks.

OSCS · Oct 5, 2012

So what is a good thickness for the tubes? What is the industry standard

powerstrokenstang · Oct 5, 2012

Di's were 1/8" thick iirc. All the cracks i had were on welds not pipe but one side was starting to droop, but at the time egt's were around 2200.

OSCS · Oct 5, 2012

Curious to hear failure points from others

dietoremain · Oct 6, 2012

This is why I love PSA, I start a thread about one thing and it turns into a FULL discussion about how to make them, who makes em, opinions, ideas, i love it haha.

steedspeed · Oct 6, 2012

powerstrokenstang said:
Di's were 1/8" thick iirc. All the cracks i had were on welds not pipe but one side was starting to droop, but at the time egt's were around 2200.

At 2200 I'd think any manifold would have trouble. I always try to keep my minimum thickness to .2 inch. I use hot rolled mild steel which is stable and has very little "tension" in it so it retains its shape when cutting it and when it is heated. Some materials and especially stainless usually have a lot of tension in them from being formed at the factory. When you cut them you get distortion as the tension is released on the side being cut. Heat also makes the material "relax" which again makes it move and distort.

Best way to explain it is that the material is crushed on the outside as it is formed. The outer surface is hardened by the crushing where the inner material is left soft. So you have a material with a soft inner core and a hard skin. Cut the "skin" on one side and the skin on the other side will contract and "pull" the material into a curve. When machining materials which are cold rolled you always have to remove material from both sides to keep it flat.

Derek@Vision Diesel · Oct 6, 2012

steedspeed said:
At 2200 I'd think any manifold would have trouble. I always try to keep my minimum thickness to .2 inch. I use hot rolled mild steel which is stable and has very little "tension" in it so it retains its shape when cutting it and when it is heated. Some materials and especially stainless usually have a lot of tension in them from being formed at the factory. When you cut them you get distortion as the tension is released on the side being cut. Heat also makes the material "relax" which again makes it move and distort.

Best way to explain it is that the material is crushed on the outside as it is formed. The outer surface is hardened by the crushing where the inner material is left soft. So you have a material with a soft inner core and a hard skin. Cut the "skin" on one side and the skin on the other side will contract and "pull" the material into a curve. When machining materials which are cold rolled you always have to remove material from both sides to keep it flat.

Do you have intention of making anything for 7.3s in the near future?

Blowby · Oct 6, 2012

:whs:
Ready to install a set if available.

steedspeed · Oct 7, 2012

Derek@Vision Diesel said:
Do you have intention of making anything for 7.3s in the near future?

Quite possible. I have some stock ones to measure. Just need some time to get it done.

Groomzybanshee · Oct 7, 2012

Blowby said:
:whs:
Ready to install a set if available.

Why no headers?

Blowby · Oct 7, 2012

Running OEM, coated at the moment. Heat was causing distortion.

silverpsd_06 · Oct 8, 2012

I figured a good stainless flange and using schedule 10 316l would be a good starting point but I have a way different idea than most of the other headers seen from the sponsors.. Whether it will work or not who knows

Groomzybanshee · Oct 8, 2012

silverpsd_06 said:
I figured a good stainless flange and using schedule 10 316l would be a good starting point but I have a way different idea than most of the other headers seen from the sponsors.. Whether it will work or not who knows

What's your idea?