Stainless Turbo Header

[Capnbondo]

Hey guys,

thought I'd share some pics of a turbo header i am building for a guy.

Plan is to make a jog to I can make a few copies.

I've made a few headers, but all one offs. Any suggestions or sample pics of header jigs? Thanks!

Not much actual welding yet- just tacked together, but I will update.

Collector:

http://www.pbase.com/capnbondo/image/95854758/large.jpg

http://www.pbase.com/capnbondo/image/95854770/large.jpg

http://www.pbase.com/capnbondo/image/95854764/large.jpg

http://www.pbase.com/capnbondo/image/95854777/large.jpg

http://www.pbase.com/capnbondo/image/95854778/large.jpg


Tacked together:

http://www.pbase.com/capnbondo/image/96028064/large.jpg

http://www.pbase.com/capnbondo/image/96028065/large.jpg

In the car:

http://www.pbase.com/capnbondo/image/96028068/large.jpg

http://www.pbase.com/capnbondo/image/96028067/large.jpg

Runner #1 needs a little tweaking but overall I am hppy with the design.

[David R]

If your welding skills are as good as your layout and fitup, its gonna be awesome!

David :)

[Kinger]

I love turbo bricks, cool!

Nice cuts/fitment. Is the center of the collector welded from the inside?

[DesertRider33]

Nice notching and fit-up!

It looks like some of those joints will be very hard to get to for welding, with all of the pipes already tacked into place.

[Capnbondo]

Thanks guys!

Yeah, now that it is all tacked together, I will remove one runner at a time, weld that runner solid, and then weld it to the collector. There will still inevitably be a few spots that are tricky to get at, but it is much easier this way than if I tried to to weld it up as it is right now- that would be next to impossible I think. :realmad::dizzy:

[MicroZone]

That's the way to do it ! This was an n/a Volvo that he's turning into a turbo Volvo?

[chopper5]

thats nice your gona post more pic's :D

[Rojodiablo]

HOLY OCTOPUS BATMAN!!!!!! That is the best looking set of headers I have seen in a while. Great taper work, really nice looking flares and fitup!!!

[malich]

Thanks guys!

Yeah, now that it is all tacked together, I will remove one runner at a time, weld that runner solid, and then weld it to the collector. There will still inevitably be a few spots that are tricky to get at, but it is much easier this way than if I tried to to weld it up as it is right now- that would be next to impossible I think. :realmad::dizzy:

I am not a professional by any means, but I would weld as much as I could on the tubes before I remove them to help with holding positioning.

Just an idea...

[Capnbondo]

Thanks guys!

I just got my 14" vertical bandsaw set up with a 1.5hp treadmill motor- it does a great job on the collector parts.

I'd be nice to have a horizontal so I can "set it and forget it" for simple cuts,
but when you are cutting miters with a really small included angle the vertical rocks!



I am not a professional by any means, but I would weld as much as I could on the tubes before I remove them to help with holding positioning.

Just an idea...

Sorry, I didn't mean to imply that I had any issues regarding how to weld it up. :cry: I've made a few of these and I have a pretty good system down in terms of the order of operations with welding them- my main issue is with respect to building a jig so I can make copies at a later date.

I've seen some jigs for simple NA headers and some of it carries over, but it is going to be tricky I think.

I may need to build the jig so that I can bolt the guides on for individual runners since different guides weill interfere with others....

In som way I'd like to make it from steel or aluminum, but I also think that making it from 2" thick dimensional lumber might be good, and fast.

Any thoughts?

Thanks again for the feedback, guys. :drinkup:

[shott8283]

after all the joints are welded.. are you going to weld the tubes on the head side of the flange and then machine it down?

im just wondering how you would go about welding an air tight bead around the pipe to flange joint when you put the 2nd 3rd 4th pipes on...

the fit up and fabrictation looks top notch!

[Shox Dr]

Looking good, what's the wall thickness and type of tube, it looks to be too thick to be Dairy Bends/tubing.

[Capnbondo]

Basically you remove one runner, weld it solid, tack it back onto the collector and flange, then weld it to the collector, then weld it to the flange. Rinse and repeat for the reast, so there is never less than 3 runners tacked tgo the flanges at one time, so nothing ends up moving around on you.

The runner is welded on the outside of the flange, not the head side.

Here is a pic from another header I did:

http://www.pbase.com/capnbondo/image/87867199/large.jpg

Hope that makes sense. You do end up having to start/stop once or twice to re-position. But in my opinion with TIG you can do this and still have an air tight joint provided you pay a little attention. :)

The material is 1.5" Schedule 10 (just under 1/8" thick). So you can easily get good penetration without going all the way through. This is nice because it avoids the whole backpurge situation.

16 gauge would be a little lighter but I would have to charge way more for 'em.

[zapster]

:cool2:

You get all the fun jobs...

...zap!

[papasloan]

Very nice job. Fit up is great. Looking forward to seeing it completely welded.
By the pics I could tell that was a lot thicker than the 16ga I use.

[Skwerly]

Very nice work, I couldn't do that in a million years lol.

[tresi]

Looks great but someone tied your tubes in a knot. How many hours will you have in a job like that when finished?

[Me!]

Wow...
How long did it take to fit it up?

[Capnbondo]

Thanks guys!

Papasloan,

do you 16 gauge 304? if so, do you use it for turbo headers or just normally aspirated? Interested to know how it is working for you.

Some people have issues with 304 cracking, even with schedule 10, so I'm interested to see how it does. i don't see why it shouldn't be fine, but who knows...


Microzone,

actually the car is already a turbo, this is just an upgrade. But, since the car came with the same motor but NA, it is common to turbocharge them.


Everyone else,

the fitup is not that bad- the bandsaw is they key factor here. Once you have some decent fixtures for the saw it's cake.

The time consuming part is planning the runners. To actually fabricate one now that I have the design might take 6 hours or so.

The first one took more like 30 hours, but I had to rework it several times to get the layout right so everything fit in the engine bay.

Pics of it all welded up tomorrow!

[papasloan]

I do custom exhaust systems for Moto Guzzi motorcycles. So far I have not had any of the stainless I have welded crack. I make headers, crossovers, and a 2 in to 1 system for several models complete with muffler. And a right side conversion with muffler on another model. So far with no cracks. ( I hope it stays that way.)
However the factory and some aftermarket pieces look to be mig welded and they crack along side the weld.
I use 304 16 ga exclusively. Prior to using stainless I used 18 ga mild steel bends. With no cracks after 5 years.
Always figured the vibration would eventually crack anything. But so far all pieces are holding together.
Hope this answers your question.

[Capnbondo]

Cool ,thanks Papasloan.

You hear a lot of conflicting information with respect to what works and what cracks with this stuff.

This header is the prototype after which 4 more will be built for te first "run".

I am more than a little paranoid about cracking, as I doubt I am able to do a good job of undertsnading the different stresses involved (heat, vibration, etc).

I am going to build a brace so that the header is not having to support all of the weight of the turbo.

Between that and it being fairly heavy gauge stainless, I am hoping it'll be ok.

I'll post some more pics later today!

[Capnbondo]

Ok all welded up:

http://www.pbase.com/capnbondo/image/96266669/large.jpg

http://www.pbase.com/capnbondo/image/96266670/large.jpg

http://www.pbase.com/capnbondo/image/96266668/large.jpg

http://www.pbase.com/capnbondo/image/96266667/large.jpg

The butt-welds are pretty much just fused at around 60-80 amps, a few drops of filler per weld maybe and that's all it seems to need.

The welds to the flanges were more like 100 amps and required a standard amount of filler.

As I mentioned before I am going to try to brace the header to the turbo weight is supported. I am also going to machine the head flange flat.

Basically I am trying to avoid any unnecessarty mechanical stresses to give it the best chance possible of having a decent life span.

It seems like with sched 10, no backpurge and less than 100% penetration shouldn't be a big deal... the big thing I don't understand well is what the thermal cycles will do.


Any thoughts?

Thanks guys!

[chopper5]

nice work looks good

[disepyon]

Nice, im in the process on practicing on this type of material as well,

I have a question, Is it necessary to leave a gap in between each fit up for full penatration? or is it ok to fit the tubes close as possible with no gaps?

Im using sch.10 tubing, im assuming that one pass on sch.10 tubing is all that is needed? since it is not as thick as sch.40 it does not require a root pass just one pass and done?

[Capnbondo]

I just got in from road testing the car with this header i have built...
:D:D:D:D:D:D:

Completely changed the attitude of the car. Man it is a beast now, I am so happy. All of the flanges sealed and everything seems rock solid. I am so stoked right now.

Disepyon,

Absolutely do NOT leave a gap. The gap will let air get at the backside of the weld and contaminate it. The fit up needs to be as close to perfect as you can get it. I have been welding the pipe using very little filler rod and around 60-80 amps. This gives good penetration without metling through to the backside of the material, again resulting in contamination.

Technically this stuff should be welded with more like 110 amps and be back purged with argon for 100% penetration, but I am hoping the fuse with 80% penetration does the job, if it does then it makes the process much easier/cheaper. And yes for a full-on sanitary sort of weld you would bevel it and run 2 passes at 50 amps or so.

I guess I'll know in a few months when the header is either still going strong, or cracked. :cry::help:

[shott8283]

that makes sense.. reason why i asked is i once saw a program where the fella welded the runners to the head side of the flange and then used a very large belt sander to flush down the face of the header flange


i like your method better.

[A_DAB_will_do]

Capnbondo,

I've done some metallurgy on stainless exhaust systems for the automotive industry, so maybe I can shed some light on this for you.

Stainless steels go through some changes when heated up to temps between 800-1600°F. Being this is a part of turbocharger, I'm going to assume that it gets at least this hot. If you used a low carbon grade of tubing and filler, you should be alright. The changes I referred to are in part driven by the presence of carbon in the steel. No carbon = no changes.

The bad news, and the thing I don't like about using Stainless in exhaust systems upstream from the catalytic converter(where temps are very high), is that the exhaust gas stream is full of carbon(CO, CO2, and a soup of partially burned hydrocarbons). There's also a lot of water vapor. If the steel spends a prolonged period of time in the critical temperature range, the carbon in the exhaust gas will slowly move into the steel. This in turn will degrade it's corrosion resistance. Combine this with heat and water vapor and you'll see corrosion of the stainless.

Generally speaking this corrosion is widespread and progresses slowly from the inside out; so that most people are satisfied with the lifespan of the components. But weld them incorrectly, and you can see much more rapid failures. Everything you've done looks good to me, so I don't see you having any problems. I'm assuming from what you've said that you don't have any sugaring on the back sides of the welds. This would be the best indicator that you could have durability troubles with the weldments.

If you do see cracking, and you didn't go looking for low carbon tubing or filler, try switching to low carbon grades. I'm confident you'll have better luck with these.

There's a whole lot of other factors that influence how fast this corrosion can occur. Better grades of stainless hold out longer(300 series are good), but a lot of the OEM and mass produced aftermarket stainless exhaust components are 409SS; which is a poor man's grade of stainless. It's cheap, because it's got barely enough chromium in it to be called stainless steel.

The 304 you're using is much better than 409. But if you need more longevity you could look at using 316SS, or on of the better Ferritic grades like 436SS or 446SS. These grades are better for high temp corrosion, but will be much more expensive. I don't know if these are available in the right size tubing either...

The other factor that's important is that if you heat the stainless up above 1600°F, but don't melt it, you can actually reverse some of the degradation. This is dragging on, so I'll skip the explanation for why. What's important to know is that holding temps between 800-1600°F for extended periods of time, and introducing carbon, will hurt the material. How much damage and how long to failure is a function of time, temp, and carbon availability.

That's probably way more than you wanted to know, but I hope it helps somebody at some point...

Ok all welded up:

It seems like with sched 10, no backpurge and less than 100% penetration shouldn't be a big deal... the big thing I don't understand well is what the thermal cycles will do.


Any thoughts?

Thanks guys!

[cell]

awesome post on the stainless metalurgy. thanks.

[Capnbondo]

Thanks DAB!

Definitely not too much info, I love metalurgy.

I welded it with 309L filler, so that should help.

No real sugaring anywhere- as mentioned I shoot for ~80% penetration so I know I am avoiding it.

There might be tiny spots at some of the flanges, but the flanges have pretty healthy fillets that are burned in well.

You can get 316 in the same tubing, it's roughly 50% more expensive I suppose.

Ideally I'd like to be using backpurged 16 gauge 321, but I would have to charge way more thna most poeple would be willing to pay. :confused:

Thanks for the input!

[DynoDave]

Capnbondo,

Very nice work! I recently learned how to Tig weld just to do this type of work. I work with a lot of turbo charged cars and want to build my own headers, but making that collector is very hard! I can't imagine how you did that? Any hints for a newbie?

Thanks.

[Capnbondo]

Hi Dave,

I use a vertical bandsaw that has a miter slot in the table.

I use a miter gauge with a block clamped to it that is cut to the angle I want to cut the taper at. Put the piece of tube against the block, push it through the saw.

It is a little slow but it works very well. You would need a fairly elaborate/expensive setup to do a better job than the vertical bandsaw and simple jog do.

Best of luck!

[DynoDave]

Would it be asking too much to see a picture of your Bandsaw, Miter Guage and block clamp so that I can get an idea of what you are doing? I think I picture it in my head but want to be sure.
Do you cut each tubing it the same spots?

[lish189]

Any updates?? Did it crack?

[Capnbondo]

Nope, no cracks as of yet.

Over time I'm sure the material will gradually degrade, but I have a feeling that time will be measurable in years, not months, which is good enough for me honestly.

At this stage of the game it seems that well thought out bracing is key- because regardless of if the material degrades or etc, if you have minimized the amount of mechanical load and vibration it sees, you will have a hard time getting it to fail even if the material degrades or the welds aren't the best.

The one exception might be if you do something reall goofy and make one runner way shorter than the rest and crate ways for it to fatigue due to thermal expansion. But, if the runners are reasonably long and equal I think they tend to be able to "breathe" and just expand and contract as they need do without introducing crazy stresses.

Brace the turbo flange itself back to the cylinder head somewhere and you're good.

[89coltgt]

The header looks great and turned out very well. I too would like to see the bandsaw setup, I plan to fab up some headers for my 4g63t powered cars/truck. Are you able to get into all of the tight places while finish welding with a full-size torch? I have aways wondered how guys get the runners welder completely, but you approach would work great, when you tack everything up, I am going to assume it is all simply fused at multpile points on each joint

[jk35]

Quite impressive workmanship! This is EXACTLY what I was hoping to find here, and you can count me in as a third request for photos of your setup, ~in fact ANYTHING that you care to share regarding your awesome headers.

I also came here looking for some advice/direction over what to use to weld stainless (schedule 10) headers. I have used my trusty Hobart Handler 135 MIG for years now, but am expecting I need to purchase/learn/practice TIG before I can even hope to obtain successful results on my own turbo headers. Correct? or is it possible to build something like this with only a MIG?

[Capnbondo]

Thanks,

check out this thread for a video of how I cut them these days:
http://weldingweb.com/showthread.php?t=24007

This is roughly 5x faster than the bandsaw. If you don't want to spend the cash for a dry cut saw, you should be able to do something similar with a standard chop saw.

In terms of welding, you could technically buy stainless wire and a 98/2 ar/co2 gas, but it would deifnitely be less than ideal.

I would either use mild steel or look into a TIG machine if you really want to do stainless.


:drinkup:

[Rojodiablo]

Quite impressive workmanship! This is EXACTLY what I was hoping to find here, and you can count me in as a third request for photos of your setup, ~in fact ANYTHING that you care to share regarding your awesome headers.

I also came here looking for some advice/direction over what to use to weld stainless (schedule 10) headers. I have used my trusty Hobart Handler 135 MIG for years now, but am expecting I need to purchase/learn/practice TIG before I can even hope to obtain successful results on my own turbo headers. Correct? or is it possible to build something like this with only a MIG?

It's one of those things; it takes a good dose of figuring out which tube needs to be welded first, and where, and then putting it all together. A mig could do the job, but I would say the visual appearance will not be tip top with a small machine. (It's the lack of features, not the power.) When I mig SS, I don't buck up for the tri-gas mix, so the welds are not quite as pretty as they could be. To practice, I agree with Capnbondo, start with mild tube to learn on, then move up to SS. You can get decent mig welds on mild tube, and so long as you have a thicker wall tube, you won't see failures. Not to say there will never be cracks; there very well may be a few. But it is easy enough to learn on mild tube, and then move up to the SS.