Steam pipe manifold construction

FJ RB25 · Mon Jan 20, 2014 11:17 am

Hi all

I'm about to attempt my first steam
Pipe exhaust manifold for a turbo 2.5L Nissan motor into my old Holden.

I have ordered the 6 into 1 collector with T3 flange and the manifold to head plate

Anyone attempted this before and what tips do you have.

Cheers
FJRB25

AFSATCOM · Mon Jan 20, 2014 11:35 am

Ok I'm not familiar the the term steam pipe manifold. Did a search and all results were Australia and New Z. Is there something that makes it different from a normal manifold or is it just a term you normally use? What material are you gonna try to make this out of?

FJ RB25 · Mon Jan 20, 2014 11:44 am

AFSATCOM wrote:Ok I'm not familiar the the term steam pipe manifold. Did a search and all results were Australia and New Z. Is there something that makes it different from a normal manifold or is it just a term you normally use? What material are you gonna try to make this out of?

I guess it must be an Australian term

Over here we call heavy walled mild steel pipe steam pipe.

Basically you weld together 90 deg, 45deg and straights to make a custom turbo manifold.

I have attached a picture of something I intent to make

: ImageUploadedByTapatalk1390232663.804793.jpg (77.86 KiB) Viewed 5919 times

FJ RB25 · Mon Jan 20, 2014 11:45 am

What does everyone else call these manifolds ?

AFSATCOM · Mon Jan 20, 2014 12:14 pm

Turbo manifold is fine but, from here on I'll know what someone is talking about when I hear steam pipe. I'm not the best source of info for this kind of thing but I have come across some good info on it.

http://www.stainlessheaders.com/headerfabrication
Here is a good set of videos on the process. I know it's with staiinless and it's not turbo but it shows a few key steps such as building a mock-up and a jig. Also, the better you make your cuts, the better everything will turn out. How thick is the wall on what you're using anyways?

AFSATCOM · Mon Jan 20, 2014 12:22 pm

And plan your joints out carefully or else you will end up with

FJ RB25 · Mon Jan 20, 2014 12:22 pm

That's great, thank you for the link to those videos, will be having a very close look in the morning.

Stainless or mild steel as you have said the basic process is the same.

It's making the jig etc that is a big part of getting the manifold accurate and as you said the joints are very important too, thank you for the tips.

I think the pipe is about 3.5mm thick and 32 mm ID.

Anyway off to sleep

Thank you once again for the tips and links

Much appreciated

Cheers FJRB25

noddybrian · Mon Jan 20, 2014 3:13 pm

Wow - that takes " Hill Billy " to a whole new level - is anyone owning up to making that fine " custom " manifold ! & can I ask what medication they're on !

Markus · Mon Jan 20, 2014 5:02 pm

Steampipe does not only stand as high temperature grade, but it is also seamless. It have to seamless due to erosion caused by fast flowing steam. To my knowledge a bit chromium added to plain carbon steel raises range of temperature area.

Just make sure you get the right steel grade. As we know exhaust have to stand very hot temperatures and stress, which is caused by continuous cooling and warming.

Due to stress, good root and penetration is one factor that should be considered.
Perhaps pipe wall thickness could be a little less than 3.5 mm, like 2.4 mm.

Bill Beauregard · Mon Jan 20, 2014 6:55 pm

noddybrian wrote:Wow - that takes " Hill Billy " to a whole new level - is anyone owning up to making that fine " custom " manifold ! & can I ask what medication they're on !

Have you never watched Gilligan's Island? The professor built it for the bamboo car.

coldman · Tue Jan 21, 2014 12:21 am

Here in Australia, "steam pipe" means pipe that conforms to AS1074 which has several common grades:
- light grade
- medium grade (also called water pipe) commonly used in fire sprinkler systems
- heavy grade (steam pipe) commonly used in saturated steam systems which is normally about 800kPa operating pressure.
- extra heavy (refrigerant pipe) which we are no longer able to use. We now must use sched 40 pipe for refrigeration.

This AS1074 pipe is available in black or galvanised, plain end or screwed and socketed. It is cold formed and electric resistance welded seam that is usually ugly and has not been skimmed, followed by eddy current test. It is cheap pipe and comes without heat certificates and is basically just a mild steel pipe for nominal applications. If the steam application is superheated, it probably could not be used legally or morally. Schedule 40 or higher pipe would be applicable in this case.

This size of pipe in question looks like 32NB (1-1/4") which is 42.4mm OD and 4mm wall which is therefore 34.4mm ID and has a rated working pressure of 1030 kPa (150psi) at 192 degrees C (378F).

The only butt weld fittings available here (elbows etc) are conforming to API5L which usually are slightly different in dimension. In this case it is 42.2mm OD and either 3.56mm sched 40 or 4.85mm sched 80 wall so there will be a high/low mismatch.

Is this the kind of pipe you auto guys use for turbo exhaust manifolds?

Tue Jan 21, 2014 12:48 am

I wouldn't plumb my crapper with pipe of that grade...

I suppose it works for a turbo, if you don't mind tieing an anvil or two to your engine...

Sorry, but that's just not how I'd do it.

Steve S

GreinTime · Tue Jan 21, 2014 1:56 am

Collin's (ToxicFab) new Evo manifold collector, albeit not welded, is some pretty beefy stuff, as are some of his other collector designs. Every RB25/26 I've ever worked on (or seen in person) had .065 wall 304 or 316 stainless I believe, which would be much lighter than boiler pipe. As Steve said, I wouldn't plump my toilet with that let alone the turbo manifold for my RB25DET.

What trans are you using by the way? I know it's off topic, but I'm always curious, as everyone seems to have a different preference for when they are swapping engines about

FJ RB25 · Tue Jan 21, 2014 11:44 am

I know you guys say you wouldn't plump your crapper with that pipe but over here in Australia as well as New Zealand everybody I mean everybody uses this pipe,

oh and these manifolds made out of this pipe are exported all over the place including the good old U S of A as well for roughly twice the price we pay over here so these manifolds must be sort of ok!

Tried and tested on many drift cars and race cars.

The problem with Stainless from what i am told is it cracks hence the reason they use steam pipe.

FJ RB25 · Tue Jan 21, 2014 11:46 am

GreinTime wrote: What trans are you using by the way? I know it's off topic, but I'm always curious, as everyone seems to have a different preference for when they are swapping engines about

Standard 5 speed manual box

FJ RB25 · Tue Jan 21, 2014 11:48 am

Just a few examples

: ImageUploadedByTapatalk1390319237.381008.jpg (149.95 KiB) Viewed 4655 times

: ImageUploadedByTapatalk1390319262.079202.jpg (37.47 KiB) Viewed 4655 times

: ImageUploadedByTapatalk1390319276.231026.jpg (76.23 KiB) Viewed 4655 times

GreinTime · Tue Jan 21, 2014 12:04 pm

Im not saying it doesn't have its purpose, because it does, its just not something I personally would do. Steam pipe definitely would retain thermal energy much better than thin wall stainless or steel tubing, but as Steve said, its heavy! And I know they are used the world over, I just giggle at the prices people pay for them. My buddy just payed $1800 USD for his. Its a well crafted piece for sure, I just can't justify paying for an emulated cast manifold. And stainless shouldn't crack if the right alloy is used, and it is welded properly. The problem is when stainless flips between austenitic and martensetic and ferritic. My dad just said a duplex stainless would work better, I believe he said something like a 2205, and that it has less creep, I.e. thermal expansion.

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AFSATCOM · Tue Jan 21, 2014 12:18 pm

With the temps that some of things get to, I can see why you would lean towards mild steel over stainless especially in racing applications as the heat would be too much for most grades of stainless. 304 would be my last choice for any turbo system.

FJ RB25 · Tue Jan 21, 2014 12:24 pm

GreinTime wrote:Im not saying it doesn't have its purpose, because it does, its just not something I personally would do. Steam pipe definitely would retain thermal energy much better than thin wall stainless or steel tubing, but as Steve said, its heavy! And I know they are used the world over, I just giggle at the prices people pay for them. My buddy just payed $1800 USD for his. Its a well crafted piece for sure, I just can't justify paying for an emulated cast manifold. And stainless shouldn't crack if the right alloy is used, and it is welded properly. The problem is when stainless flips between austenitic and martensetic and ferritic. My dad just said a duplex stainless would work better, I believe he said something like a 2205, and that it has less creep, I.e. thermal expansion.

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I agree they are very heavy indeed, and $1800 US is a lot of money to spend on a manifold, that's the whole reason I'm going to give it a go myself. Save the money and gain some new skills and because my project is not something you can buy off the shelf for.

We get a lot of those cheap Chinese SS manifolds over here which also gives SS a bad rep when it comes to a turbo manifold.

Manifolds here range for a good quality unit from $800 AUS to a well known unit with lifetime warranty $1260 AUS.

Postage would be the killer to the States.

I was looking at getting a Forced Performance turbo from Texas to Oz and it was not cheap, wish I got it last year when I was over there with work.

GreinTime · Tue Jan 21, 2014 12:52 pm

Forced Performance makes some killer turbos!

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WerkSpace · Tue Jan 21, 2014 4:01 pm

In Canada, titanium pipes are becoming popular. I've found some titanium headers at the metal recyclers and they are very, very light weight. The funny part is, that the recyclers think that they are stainless steel, so I buy them for a buck a pound. A quick spark test will tell you if it is stainless or titanium. (White sparks for titanium.) https://www.youtube.com/watch?v=Hfg2_DAaq2A

kiwi2wheels · Tue Jan 21, 2014 5:56 pm

See if you can locate .063" 321 stainless tube. It was the usual material for the turbo Indy cars ( CART era ) until the budgets went crazy( ier) and Inconel became the fashion.

Weld it with 347 rod.

GreinTime · Tue Jan 21, 2014 6:07 pm

+1 for that^^^ One of my teachers welded with Wyatt Swaim at the Indiana Oxygen Garage at the Indy 500 and had said that they (the manifolds) held up exceptionally well, as this was a question a different student had asked.

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FJ RB25 · Thu Jan 23, 2014 4:21 am

321 stainless hey, worth a look around I guess and would look a lot sexier than the old steam pipe.

I think that all these cheap Chinese manifolds have given the old Stainless a bit of a bad rap over here.

Wyatt Swaim is a legend, have seen some of his videos, be good to know half of what he knows

FJ RB25 · Thu Jan 23, 2014 8:59 am

WerkSpace wrote:In Canada, titanium pipes are becoming popular. I've found some titanium headers at the metal recyclers and they are very, very light weight. The funny part is, that the recyclers think that they are stainless steel, so I buy them for a buck a pound. A quick spark test will tell you if it is stainless or titanium. (White sparks for titanium.) https://www.youtube.com/watch?v=Hfg2_DAaq2A

Hi Werkspace

That's very handy to know, it's something I have never thought about really because majority of the materials I have worked with are mild steal and Ali

That's one I will be remembering, thank you once again