cast steam pipe bends

[Dreamkiller]

1. Sorry I was referring to "CAST" steam pipes.

2. I didnt mean to say normal mandrel bent pipes

you will find that their manifolds are made from mild steel steam pipe bends.

3. I dont know of any seriously quick cars with stainless steel exhaust manifolds. They more often than not crack from the heat produced, due to the thermal expansion properties from stainless.

The objective of using thick walled pipe is strength to hold the weight, and to keep more of the heat inside the the pipe and exited out through the exhaust to keep under bonnet temps to a minimum.

 

[Pro]

um... huh? what do you think heat is?

it's ENERGY! the more energy that passes into the hot side of the turbo, the more energy is present to spin the thing...

don't mind me, i was way wacked when i wrote that.

 

[Miles B]

OK.. are you still high?

Cars with stainless manifolds that I can think of off the top of my head:
Titan Motorsports 8 sec Supra - Greddy T88, don't have the specs on their 7sec Celica, but I bet it is the same motor.
HKS Supra
249mph Jun Akira Supra
SVSi 8 sec Stryker TT Viper

EVERY fast car I can think of has stainless headers. Indy cars used to have stainless before titanium got popular. Cast steam pipe manifolds are for poor people like us. Design it properly with expansion in mind, and it will not crack. Thin wall stainless holds heat in better than thick wall cast steel. Thin pipe always holds more heat in than thick pipe! Always!

I still don't understand your first post. You are saying they are made from cast steam pipe, then you say cast steam pipe is not good. Please explain what you mean more clearly.

 

[Pro]

I still don't understand your first post. You are saying they are made from cast steam pipe, then you say cast steam pipe is not good. Please explain what you mean more clearly.

is that directed at me...? wha...?

and for the record, not high, just WAY tired.

brainey no workey good like when tired.

 

[Miles B]

Nah, sorry, to Dreamkiller.

 

[Dreamkiller]

My first quote

you will find that their manifolds are made from mild steel steam pipe bends.

NB: No mention of Cast

Then i said or tried to say that Cast may be appropriate for steam pipe applications, but maybe not so for exhaust

 

[Miles B]

What is wrong with cast for exhaust? There are plenty of cast iron and cast steel manifolds. What do you think stock is made of? I think you would be very hard pressed to build a turbo manifold out of mild steel. Mild gets bendy when it gets hot like that, and it also rusts REALLY fast when it is hot. You can get black steel extruded tube, which is like the cast steam pipe sections, in that it doesn't rust easily. I've never seen anyone bend that stuff though. The walls are simply too thick.

I have asked around, and noone I know knows any serious car with anything less than stainless manifolds. The really high dollar jobs are running titanium or inconel, especially in rotaries. If you can afford to go racing under 10 seconds, you can afford to have a tig weldor do stainless thin wall manifolds. Manifolds made of heavy gauge steel, such as steam pipe, are purely low cost.

 

[Pro]

with rotors using steel, the thicker the pipe the better.
thick pipe suppresses noise, and you'll find a lot of rotors run thick walled headers to stop them sagging and cracking due to the exceptional amount of heat they create.

titanium and stainless are good to use - but even on a rotary exhaust, stainless will crack.

FTR, over here in OZ we're getting rotors into the ten second zone on as little as $15k AUS - which is the price of a new hyundai.

 

[autocol]

The really high dollar jobs are running titanium or inconel

i was going to mention inconel...

from what i've heard that's what the F1 guys use, with a wall thickness of 0.5mm!!

 

[Lexurious]

Obviously it comes down to cost. Inconel and 321 stainless would be the best but I couldnt even find them in Australia, let alone afford them. Titanium is difficult to weld and is expensive also. Cast is cheap and does the job but it is heavy and most wont use it for this reason. Stainless only cracks at high temps if it is low grade, 302, 304 etc.

 

[racingbrett]

seems a lot of aftermarket turbo kits run with 321 and lower grade stainless manifolds,
but i know of a few draggers here in the uk with home grown twin turbo systems using plumbers black iron pipe, and welding bends. which any plumbers supply should have in stock, not sure if this is the same as your cast steam pipe but it works well for them ?

is it welding cast that gives of toxic fumes?