Sorry if this stuff has been answered, I searched but couldn't come up with definite answers:

I'd like to make the header flange from 3/8" thick 304 SS, is that thick enough?

I'd also like to use 304 .065 wall SS for the tubes, is that enough or do I NEED to use sch 10 or 40?

I have seen numerous flanges cut between the runners and Corky Bell states that it's a good idea to cut the flanges in between the runners to eliminate problems with thermal expansion, is this correct?

What is the best way to brace the turbo, I've seen a few setups using heim joints, is that the answer?

Should I use a slip collector or will a 4-1 using the tubing welded to flange be OK?

Thanks a bunch guys, I love this forum.

D.


Modified by Masta at 12:03 PM 11/9/2004

 

Anybody?

 

I personally suggest the use of 1/2" flanges because they are more heavy duty and do not warp as much during the welding procress. We sell 304 Stainless flanges as well at http://www.exploitedracing.com

16 gauge (.065") tubing is rather thin for a header holding a 20lbs turbocharger and will most likely crack, Schedual 10 or 40 is much mroe highly suggested due to its thicker construction. As for the flange being cut between ports, its definently helps prevent cracking, but is most efficive on log manifolds, lately i myself havent been stress cutting tubular headers because they usually flex more throughout the tubing.

 

ok here we go

3/8 material is plenty thick, if you are inexperienced in welding or dont feel comfortbale use mild steel. otherwise weld as normal and give the flnage a quick surface on a face grinder

The recommended materail for turbocharged application is 321 16.ga or .065 wall.

You should be ok with 304 as long as the weight of the turbocharger is well supported.

We have not experienced any problems with one piece solid flanges. Most times when the flanges are cut it is too relieve stress that is induced into the flnage after welding.

You want to fabricate a Tripod mount using heim joints would be the preffered type

You should preferrbaly use a double slip collector or at least single slip (no it doesnt have to be ours either ) This way the manifold can expand and contract without an obstruction by the collector

Hope this answers your questions

 

What is a tripod mount using heim joints, any pics? What is a single slip collector? I assume I should mount the turbo and collector to a tripod mount(whatever that is) and then fit the header into the collector with a slip fit, is that correct? My plan is to weld the header while its attached to an old cylinder head to keep it from warping, will this help? I am an experienced SS Tig welder, but this will be my first attempt at a tubular turbo header, is there a certain way to weld it? Should I tack it all in place then weld it or can I tack it all then break the tacks at the flange and weld the runners individually. I will be backpurging as well so no sugar One more thing, after welding I was planning to mill the surface of the flange to make it flat, is this a common practice?

Thanks

D.

 

321 stainless really is not needed for a turbo setup so ignore that... hes just trying to sell the stuff (i noticed the burns-stainless link in his signature)

The thermal condutivity of 304 stainless steel is 113 BTU-in/hr-ft²-°F

while the thermal conductivity of 321 stainless steel is 112 BTU-in/hr-ft²-°F

odd... i see very little difference. Which means both materials hold in nearly the exact amount of heat! 304 is perfectly fine for a setup and will work just the same as 321 only a lot cheaper. Not to mention the 304 peices are thickers than 16 gauge 321 so will acually hold in even more heat due to the thickness increased.

Material information was taken from http://www.matweb.com based on AISI Standards for annealed sheet (tubing information not avialable)

 

exploited racing

I'm glad that you looked into all the properties that matter at elevated temperatures.

321 has a lower coeficient of thermal expansion as well as lower coefiecent of thermal conductivity it also had a better lb/in tensile strength rating. The material itself is simply a better choice at elevated temperature

Comparing materials different thickness and grades is apples to ornages compare 321 of the same thickness and it is still superior. thats like saying well this pushrod V8 does this and this quad cam v8 does this.

Cost wasnt listed as a factor so i didn't take it into account.

You or anyone else can buy your stainless where you choose im not trying to sell him anyhting he asked a question i gave my educated opinion.


As far as a tri pod mount using heim joints i don't have a picture. the mount should hold the center section of the turbo firmly and mount to a secure location on the black and or the head in at least two places.

a single slip collector is this




The double slip looks like this



The double slip allows for an extra sealing surface and allows the header to expand and contract

When we do headers here we make the fab the header tacking as we go tack everyhting in place and check for fit. Break the tacks on the flange and weld the tubes. Then we fixture the tubes back in re-tack it and do a final weld on the flange.

We dont mill we just resurface on a face grinder so a mill is even better


I hope this helps

and for exploitedracing im glad helping somebody means im trying to sell something. As i even told him above it doesn't have to be our collector or our material.

Thanks Casey

 

sorry to come off like an *** and everything, i have ordered from burns before acually. I ordered some 321 stainless tubes because i myself wanted to try it out. Now yes if you were to take schedual 10 321 stainless and compare to 304 then 321 would have a higher Ultimate break point and less thermal conductivity, HOWEVER 321 does meet its yielding point at a lower stress amount.

And for those curious of the strength levels between 304 and 321 here it is..

304 Stainless:
Tensile Strength, Yield 37,700psi
Tensile Strength, Ultimate 84,800psi

321 Stainless
Tensile Strength, Yield 34,800psi
Tensile Strength, Ultimate 89,900psi


Yield Strength represents pressure at which materials begins to deform, Ultimate strength represents pressure at which material breaks.

 

Thanks guys for the very technical responses, very interesting. Now how about SS 316L, I never see it used, how come? As far as cost goes, it is DEFINITELY an issue so a Burns collector is out of the question. I know it's a good piece and I'd love one, but it would be more than my entire turbo budget

So far I've decided:

3/8" SS header flange
single slip collector(don't know how yet, but I'll figure it out)
turbo mounted to the block with collector attached
tack all in place, break tacks weld all runners then weld to header flange while attached to a head, then mill flange
304L or 316L SS .065 tubing for runners
2.5" SS IC piping
3" SS downpipe with internal wastegate vent tube routed back into DP downstream

Thanks for all your help guys, I hope I'm on the right track.

D.

 

https://honda-tech.com/zerothread?id=1042726

sorry had too our collectors here for cheap!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ExploitedRacing &raquo;</TD></TR><TR><TD CLASS="quote"> We sell 304 Stainless flanges as well at http://www.exploitedracing.com</TD></TR></TABLE>

who tried to sell something first?

 

Ive thought about using 304 for the flange, and 316 for the runners, anyone know the properties of 316?

 

I believe that's the route I'm going to take, it can't hurt to use 316L, it is very nice stuff and I just happen to have a bunch of it laying around.

D.<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jmckeone &raquo;</TD></TR><TR><TD CLASS="quote">Ive thought about using 304 for the flange, and 316 for the runners, anyone know the properties of 316?</TD></TR></TABLE>

 

316 contains the same properties at 304 stainless steel but is more corrosion resistant to salt water which is why 316 stainless is used for outboard applications such as boat exhausts.

 

Good to know, I can save a few bucks then and use 304L.

D.

 

I'm thinking of using 1.5" bends and tubing to keep velocity high in the manifold? Any thoughts?

D.

 

1.5" should be perfect...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ExploitedRacing &raquo;</TD></TR><TR><TD CLASS="quote">316 contains the same properties at 304 stainless steel but is more corrosion resistant to salt water which is why 316 stainless is used for outboard applications such as boat exhausts.</TD></TR></TABLE>Isn't it better at handling high temps?

 

1.5 is fine

 

the deal with the L designation in 304L and 316L is for ELC, extra low carbon in which the carbon content is .03% max. there is also S designation which is .08% max.

the reason for low carbon is this. the 300 series of stainless steels is like 18-25% chromium and 8-20% or so of nickel. the chromium offers exceptional resistance to corrosion, however at 800-1500 degrees the chromium likes to bond to free carbon atoms creating "carbide precipitation" which leaves the material vulnerable to "intergranular corrosion" from lack of chromium in the areas adjacent to the fusion line where the temperature was in that critical range for a significant period of time.... basically stainless steels thats not so stainless anymore.

youve got some options. first, get rid of the extra carbon that the chromium attracts to. hence 304L and 316L. second, you can alloy in some titanium, which is what 321 does and i suspect the reason why its more expensive. 321's ideal use is in highly corrosive environments. im not sure how much an improvement it is over 304/316 for a turbo manifold, provided that you can compensate for the carbide precipitation alternatively. you could also use 347 if you really had $$, im not entirely sure what alloys are added in 347.

another option is to weld rapidly with high heat and quench. this will minimize the duration that the adjacent base metal is in the precipitation temp range.

another consideration is yield strength AT ELEVATED TEMPERATURE, not ambient. i need to do a little more reading on material properties first, but i do know that the 200 series stainless was developed as a replacement for 300 series by reducing nickel and adding manganese, since nickel has critical shortages during wartime. probably significantly cheaper.