New header

[importwarrior]

and what type of loan would you need to get Inconel ? tubing and flanges?

[Chad]

If you are comparing 1-5/8" 180* mandrel bent tubing, 1018 mild steel is ~$12, 304 stainelss is ~$20, 321 stainless is ~$35, and 625 Inconel is ~$120.

 

For pipe, I'm sure the cost differences are similar, I found a place that sells inconel pipe elbows, so I know they exist, but thy are not replying to my quote requests.

 

The material alone is $600 for a simple inconel headder, over $1000 for a long tube race headder. Labor is ~$250-400 on a headder depending on design.

 

I actulay purchased a huge lot of mandrel bent Iconel tubing from ebay, I'll be making some race only inconel headders this winter. Possibly a few street versions as well.

[TopDawg_43]

The more you use it, the harder it gets, but eventualy it will become brittle and that will cause it to fail.

 

How long, do you think, before this happens.

[heefner]

The more you use it, the harder it gets, but eventualy it will become brittle and that will cause it to fail.

 

How long, do you think, before this happens.

 

lol as the panic sets in. Hopefully later than sooner but everyone that participates in this forum needs to realize that when you start making 2x+ the stock power you WILL be replacing parts.

[importwarrior]

my opinion a header is not the best for a daily driver. if it was a weekend driver id say no problem. but everyday driving will kill a header 10X faster. my .26 cents !

[Chad]

It all depends on the material used, external forces (vibrtions and weight of turbo/exhaust), time at specific tempertures, frequency of the thermal cycles, peak and nominal opperating temperatures, and a few others.

 

It's all terribly varriable, but if you do any of the above excessivly, you will be replacing it more often that not. A steet car with "normal" boost, a flex section in the down pipe, and cooled off after hard runs will live far longer than a car that has 1700* EGTs, runs no flex, runs hard and gets put away hot, and has no exhaust hangers (exhaust weight hanging on the turbo/headder).

 

take a piece of metal and bent it back and fourth in one spot, eventualy it will break. A headder is no different. Heat cycling metal causes molecular changes to it, those changes compound with time. Some alloys have additives to minimize these changes, but they still happen.

 

Keep in mind, even the stock manifold cracks at stock power, don't think it's because they were made in someones garage, they were made by a $multi-billion$ dollar company with limitless R&D at their disposal, and they still crack. It's the nature of the part, not a design flaw.

[Boosted_One]

...everyone that participates in this forum needs to realize that when you start making 2x+ the stock power you WILL be replacing parts.

 

Yup!! The chances increase more and more the more ya make.

[jinx]

weld els not as pretty and end up heavier but thats all we make/use around here... never seen one crack. Inexpensive also

Most of a top mount manifold is out of view anyhow and should have some sort of a heatshield. Can look nice when coated too.

[ALANFROMPDX]

This is why cast manifolds are better.

But before i get into a long drawn out reply to this post i will read it first.

And respond again if needed.

[lionbull]

This is why cast manifolds are better.

But before i get into a long drawn out reply to this post i will read it first.

And respond again if needed.

for durability perhaps.

Lets keep it real here for a second the very reason this thread was started is because somebody wanted something better suited for performance. If you want to end up with burnt exhaust valves and cracked heads on the exhaust side of your "PERFORMANCE" ( if you are making 280 whp and up) motor then the stocker manifold is the right choice for you(everybody).

[TopDawg_43]

Just as long as Chad is still around in 20 years or so, or whenever it decides to crack, so I can buy a new one. No problem.

[Starcon88]

John and I use weld Els and yes they are heavier but we also weld bracing from the header to the block but the bracing need to be thin enought where it will want to flex with the header when it is under heat. Its kinda crazy not too, you have the weight of the turbo and part of the exhaust system on just what 8 studs into aluminum and the heat they put out. Thickness and brackets are the best rough IMO

[ALANFROMPDX]

I have 13 years of experience and a degree in Investment casting.

Am I an expert, NO.but i can give some insite.

 

This is a great post.

 

Heattreating , cast vs fabricated.

I don't want to get this post off topic but here we go

 

Cast is better in my opinion because you can choose a better alloy than stainless. You can get away from heattreating it too.

Ideally I would heat treat it but for stress relief.

A part casting that has been straigtened requires heattreat or it will go back to its orginal shape.

 

I would cast inconnel which is the material the impellers are made of.

The company i worked for is still the leader in investment casting in the WORLD and does the impellers for garrett.

 

Lionbull I am glad you countered me on my statement as it needs clarification.

 

316 is great to work with but inconnel is what i would cast if casting.

 

316 would be good for welding and inconnel tubing would be awesome.

 

Airforce 1 is a boeing plane for the president. Its parts for the GE engines were identical to the boeing commercial engines.

the boeing version for planes you and me fly on were inconnel 718 i think.

but Airforce 1 parts were a special grade of titanium.

the engines were close to half the weight but parts were changed more and the performance of the turbo props was not the same. And all of our cast parts were heattreated.

 

I am losing my job in Telecom and running back to investment casting.

I thought communications would be good for me but my 6 years on these boards i have realized manufacturing and metallurgy were in my blood.

 

May of next year i should be back to Casting Industry for good.

 

You will all know when this happens.

 

-Alan

[TopDawg_43]

On my job,

 

Aluminium- $.05/lb

Stainless Steel- $.38/lb

Inconel- $5/lb

 

That's how much we pay for scrap pieces and we buy it in bulk.

[ALANFROMPDX]

1.5 inch ID tubing has a home with me.

 

you are sitting an a good side business.

[lonestarion]

heat treating isnt the same as stress relieving.

321 stainless doesnt require heat treat but the closer you get to 300

the more it needs to be heat treated.

when a material is welded you change the structure around the heat affected zone, heat treating brings the the material to the same

structure, thus eliminating the chance for stress fracture.

 

stress comes from a material(header for example) that is locked into a set positon and is cycled through a heating/cooling process. when any metal is heated(welded) its gona bend,twist and move. this process inturns locks a set amount of stress into a header. then without stress relieving and heat treating, the weld area will prematurely crack. stress relieving unlocks this set amount of stress.

 

so you see heat treating "IN A WAY" is the similar as stress relieving.

but they have 2 different definitions and shouldnt be consisderd 1 in the same process. i have been fabricating,welding metal (mild steel,aluminum,stainless)in fabshops,machine shops,shipyards,aircraft for 18 years. yes i do know the difference between the 2, and whoever told you that both where the same thing is wrong. not try'n to degrade you or the work your doing, just letting you know the difference and that both are not the same nore have the same process. so everythings kosher with me, keep on keep'n on....

[heefner]

Wouldn't the process be negated the first time I run 1600 degree exhaust gas through the manifold bolted to the head?

[Chad]

That is my point hefner, you heat threat the part every time you use it, including the weld areas (HAZ) and the main sturctures (non HAZ).

 

the parts of the manifold all reach the same aproximate heats, and are kept there in some cases for extended periods, and they all cool at about the same rates, sounds like a quasi heat treating process to me, which is why I don't see the need for the added expence of heat treating it before it's put into use.

 

Heat treating to remove built up stresses makes sense on a parts that is used and opperated below ~800 degrees, but a headder is no such part.

[emagdnim]

Page 5 and no pictures/products.

 

This thread sucks. :wink:

 

keep yapping on, not getting any work done.

[Boosted_One]

Page 5 and no pictures/products.

 

This thread sucks. :wink:

 

keep yapping on, not getting any work done.

 

 

Page 1 of this thread , the very first post, contains the pics of the header in which this thread is referencing to.

[emagdnim]

My computer didn't load them that fast so i skipped right over it.

 

My fault.

 

You guys still yap too much.. lol

[eeaston]

Heat treating to remove built up stresses makes sense on a parts that is used and opperated below ~800 degrees, but a headder is no such part.

 

As usual, Chad knows what he's talking about. Heat treating is a generic term that can denote any number of processes, including hardening, tempering, stress-relieving, carburizing, etc. etc. etc. Without tightly controlled conditions, you're more likely to hurt the part than to inprove it. The bottom line is that for most alloys of iron any proper heat treatment will go away as soon as the header sees a hard run and cools under non-controlled conditions. The material will be left in some unknown condition and there's nothing you can do about it.

 

Headers made from 321SS and inconel can be made from mandrel bends as thin as 18 ga and still hold together as long as the weight of the turbo is properly supported by bracketry. Any other readily available alloy will need to be thick enough that the mechanical and thermal stresses don't exceed the reduced fatigue limit of the material.

 

Lots of people have gotten excellent results with sch. 40 weld els in mild steel or 304SS(me included). Casting is fine, but for a garage builder and with complicated equal length runners it's just impractical.