Would someone be able to help me out with some answers regardsing manifolds and exhaust pipes please?
I'm looking into getting a manifold made specially instead of buying one as I think it could be cheaper.
I have the flange drawing off a link off here (Muchos thanks)
I'm looking to get the flange made up by a local laser company so i need to know what grade/thickness of steel to use for the flange?
What diameter of stainless tube should be used for the pipes and also wall thickness?
What grade of stainless would people recommend for the pipe?
Any help would be cushdy, cheers
M20 Exhaust Fannymold
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choppa7
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Turbo-Brown
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I got mine cut from 10mm thick 304 grade stainless steel.
You're kinda limited by what's available for the pipe sizes. Think I used 1.5" 16g which gives a 35mm ish ID.
That lines up with the holes in the flange drawing nicely, but there will be a little step out from the port in the head.
Anyhoo, I'd go for 304 grade stainless as it's relatively easy to work with and has good corrosion resistance given the heat and chemicals it'll be subject to.
You're kinda limited by what's available for the pipe sizes. Think I used 1.5" 16g which gives a 35mm ish ID.
That lines up with the holes in the flange drawing nicely, but there will be a little step out from the port in the head.
Anyhoo, I'd go for 304 grade stainless as it's relatively easy to work with and has good corrosion resistance given the heat and chemicals it'll be subject to.
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choppa7
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you're a star matey, thanks!
Am I being naive, or is it a case of getting the flange cut from 10mm stainless, then getting a load of pipe and welding it to the flange and bending to suit the engine bay/space etc?
Am I being naive, or is it a case of getting the flange cut from 10mm stainless, then getting a load of pipe and welding it to the flange and bending to suit the engine bay/space etc?
1990 318i Lux
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Turbo-Brown
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It can be. What I've been doing for my manifolds is having the flanges cut and then buying pre-bent bits of pipe. If you buy 90degree bends you can either use them as they are or cut them to different angles and so forth.
Alternatively and if you're feeling confident, you could either draw out what you need and get a single length of pipe bent up for each cylinder, or perhaps make a mock up from something flexible and have that used as a pattern.
One way or the other though, the bending will need to be done before the pipes are welded to the flange. It's 'mandrel bends' you want too, the other type are restrictive to flow as the pipe is reduced in section during bending.
Alternatively and if you're feeling confident, you could either draw out what you need and get a single length of pipe bent up for each cylinder, or perhaps make a mock up from something flexible and have that used as a pattern.
One way or the other though, the bending will need to be done before the pipes are welded to the flange. It's 'mandrel bends' you want too, the other type are restrictive to flow as the pipe is reduced in section during bending.