Custom exhaust manifolds/headers

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alexanderfoti
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Custom exhaust manifolds/headers

Post by alexanderfoti » Mon Jul 21, 2014 3:10 pm

Hi all

Just wondering how most people are going about doing this?

On my XJ, I used the original piece of header from the original exhaust, and welded (very carefully!) a piece of flexible tube onto that, then onto a rigid pipe, then all sprayed black.

Its functional, just. IT leaks here and there and looks crappy, any ideas on how to do an easier/better job?

Mine looks like this now:

Image

Ideas? :)

gilburton
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Re: Custom exhaust manifolds/headers

Post by gilburton » Mon Jul 21, 2014 7:47 pm

Ok I assume you will have no access to any heavy duty or special equipment and will be doing this at home??
Get some 6mm or 1/4" plate or similar.
Use the exhaust gasket or make a pattern for the manifold by using a cornflake packet type cardboard.
Using a ball pein hammer and holding the card on the manifold you can tap gently round the edge and it will cut out the pattern.
Then put the pattern on the plate and mark it out. You can either scribe it or put masking tape on the plate and draw round it or just use an old spray paint can and it'll leave the outline.
You'll need a pillar drill and drill lots of holes round the inside edge of the port then chisel it out and file the hole round with a half round file.
Drill out the holes for the 2 studs then either using a hacksaw or angle grinder cut round the outside of the pattern.
DO NOT CUT THE MANIFOLD OUT OF THE PLATE FIRST AS it makes it more difficult to hold!!
Tidy it all up with a file/grinder.
Obtain some old bike downpipes of the correct size(a four cylinder bike will give you plenty of bends etc.)
Instead of taking it round the front of your engine take it round the back and,as I presume you want to keep your belts clear it can either be a high level straight back ,in which case you will only have one bend welded from the manifold or you can use a couple more bends and take it to the r/h side??
Of course if you have access to a plasma cutter or a laser it makes it easy :lol:
Last edited by gilburton on Mon Jul 21, 2014 8:08 pm, edited 2 times in total.

gilburton
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Re: Custom exhaust manifolds/headers

Post by gilburton » Mon Jul 21, 2014 7:51 pm

Have a look at this solution
You'll have to scroll down to find the pics.
http://www.suckindiesel.com/thingy/view ... y&start=30

tappy
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Re: Custom exhaust manifolds/headers

Post by tappy » Mon Jul 21, 2014 10:10 pm

You can also buy pre-made bends of 1mm thick stainless tube. Arrange them - along with any straight sections - and clamp them at each joint with two half-pipes and a pair of jubilee clips. Each have pipe should have a notch or hole in it big enough to tack weld the pieces together. This way you can create the entire route "dry", then tack weld, remove the half-pipe clamps and weld it up properly.

pietenpol2002
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Re: Custom exhaust manifolds/headers

Post by pietenpol2002 » Tue Jul 22, 2014 4:19 am

Or if you've not wanting to chisel one out by hand, one of the VW Beetle exhaust flanges is precisely the dimensions you want. I just can't remember which one. They range in sizes from 1 3/8" to 1 5/8". A few minutes on Google should get you the correct diameter and bolt spacing. They're even available in stainless if you wish to get exotic. Below are several examples.

http://www.vwheritage.com/vw_spares_Ste ... m#esp_pg=2
http://tinyurl.com/pqtmtx7

I've also had good luck fabricating flanges like the one in the link below using a common hole saw for wood. Just keep the RPM's slow and use plenty of cutting oil. Just don't try it on stainless.

http://www.suckindiesel.com/thingy/view ... aust#p5921
Ron
Goshen, IN USA

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boutje
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Re: Custom exhaust manifolds/headers

Post by boutje » Tue Jul 22, 2014 8:05 am

I made separate manifold out of stainless steel.
Also build the pipe of stainless steel.
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alexanderfoti
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Re: Custom exhaust manifolds/headers

Post by alexanderfoti » Tue Jul 22, 2014 4:46 pm

Thanks for all the input guys. My welding skills are really bad, and my mig welder very bad quality, so welding things like exhausts is difficult. I'm going to try and find somebody who will do the welding if I make up the tubing. We will see.

klondikekid
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Re: Custom exhaust manifolds/headers

Post by klondikekid » Fri Dec 26, 2014 11:19 pm

Hiding under the exhaust wrap on my bike is stainless steel flex pipe, I have made up my own custom exhaust before and I know how much work it is, the bends are hell if it's your first time, I brazed mounting tabs and a chrome plated tip on the end. Quick easy and no one is the wiser.
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alexanderfoti
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Re: Custom exhaust manifolds/headers

Post by alexanderfoti » Mon Jun 22, 2015 8:43 pm

That looks really good!

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