T4 stubs complete!
 

I finally got around to making my stub pipes. These are made out of 1 1/2" .095 wall DOM tubing with 3/8" flanges, and the tabs are 5/8".

http://i52.photobucket.com/albums/g3...5.jpg~original

I made a jig to weld everything together out of 3/8" plate so nothing would move when heated up. It works for locating tabs, and then for flanges.

http://i52.photobucket.com/albums/g3...3.jpg~original

Here's a few pix of the process...

http://i52.photobucket.com/albums/g3...1.jpg~original

http://i52.photobucket.com/albums/g3...3.jpg~original

http://i52.photobucket.com/albums/g3...8.jpg~original

This is a mock up head for testing. They drop right on!

http://i52.photobucket.com/albums/g3...9.jpg~original

Now I can start my header build!!!!:woohoo:

very nice work, do you try it with the push rod tubes and check for rubbing

Very nice work indeed! You put in a lot of effort for this, respect!
Nice welds too!

stunning work! very good workmanship

Thanks guys this site keeps me going on my project alot.

Brujo65, The tubing is 1 1/2" flared to 1 5/8" with a tool I made on the lathe. The only tube that touches is the exhaust push rod tube on #1 and #4 cylinders. They don't touch very much with a stock tube I had laying around, but the tubes on the real motor were already "modified" when I built the motor at Jake's ;)

With inspiration from your jig and setup (Thanks!), I started taking some measurements, and made a few drawings. A friend transfered them into CAD, and made all the flanges.
http://i260.photobucket.com/albums/i...3.jpg~originalhttp://i260.photobucket.com/albums/i...4.jpg~originalhttp://i260.photobucket.com/albums/i...6.jpg~original


Everything is made out of 10mm stainless steel, and I made it so that the CSP python exhaust gaskets will fit if needed.

http://i260.photobucket.com/albums/i...6.jpg~originalhttp://i260.photobucket.com/albums/i...5.jpg~originalhttp://i260.photobucket.com/albums/i...4.jpg~original

I wanted as much contact surface as you can get, so I thought of these things:

http://i260.photobucket.com/albums/i...0.jpg~originalhttp://i260.photobucket.com/albums/i...1.jpg~originalhttp://i260.photobucket.com/albums/i...2.jpg~originalhttp://i260.photobucket.com/albums/i...6.jpg~original

The pipe will be notched a little and welded to them. I will be using 40mm (outside diameter) stainless pipe.

http://i260.photobucket.com/albums/i...3.jpg~originalhttp://i260.photobucket.com/albums/i...4.jpg~original

One of my buddies has a TIG welder, hopefully we can handle the job. I'll post pics of the complete stubs when they will be done :D

Very nice! I thought about doing larger flanges (like CSP) for better bolt clearance, but wanted to keep it a "standard" size. The jig will help keep everything were it should be from the heat of welding. Give your friend a "practice part" to see if he can do it or not. Welding thick to thin material can be tricky for the novice. I like to help everyone out in some way... posting "how to do it" is one of them.

BTW, my header is STILL NOT DONE :shake: but I'm trying to get the time. Almost done with a conversion to one of my power tools to aid in header builds. Will have something to post soon.

Xellex, did you notice Wrenchnride used 2 jigs for this?

IIRC, the type 4 head has the studs slightly off-centre and two are on the other side of the 'oval-flange-centerline', hence you might need two sets of different jigs for this.
Correct me if I'am wrong here as to the reason you use two jigs Wrench? (sorry, forgot your real name mate)

Now that could be a problem! I only thought he used 2 jigs in order to work faster and not flip the studs every time.
I did alot of measurements of the exhaust ports in the cylinder heads, but it's pretty hard to fit a caliper in there and get a perfect reading. Also the studs can be old and bent, and you can't get a good centerline. I haven't found the exact measurements anywhere on the web.. Actually what I did was to measure 4 different heads (8ports) and take an average of those measurements.
What I thought of, as a solution to slightly misaligned parts, is a bit larger stud holes in the 2 small brackets/tabs that get welded to the pipe.

Wally is correct. I thought it was common knowledge there are two stud patterns per head. Sorry :o . I used factory cast stubs I cut off some old heat exchangers to pattern my hole locations on the jigs. If you make the holes on the mounting tabs for the studs to go through too large you risk exhaust leaks from heating and cooling cycles. Can take a pic of the difference between the two if needed.

That would be nice, thanks! I nthe meantime, I'll redo all my measurements.

Ok, here are a few pix for you.

The one on the left is for #1 and #4. Of course the one on the right is for #2 and #3
http://i52.photobucket.com/albums/g3...1.jpg~original

Look at the studs in reference to the valve stem. This is #2 or #3
http://i52.photobucket.com/albums/g3...9.jpg~original

You can really see the difference in this pic.
http://i52.photobucket.com/albums/g3...8.jpg~original

Those are GREAT pictures to show the difference in type 4 head stud orientation!
Thanks for the effort!

Yep, thanks alot! Now I can see what you were talking about... I did the stupid mistake to assume the studs should have been originally perfectly centered, and that those in the heads that I was measuring were bent...
It's funny that by the looks of it, the #1 stud pattern isn't at least a mirrored image of the #2... I wonder if there's any logic reason why VW did them this way...
Anyway, this will make it a bit harder, as I wanted to make these by exact measurements, in order to fit them to any heads, and not only mine. That's why I had the holes drilled by CNC, not to induce any human error. Now I'm in the dark, and the best I can do, is to take an old heat exchanger like you did, and copy the pattern from that... but I'm not convinced yet.
I kept searching for original measurements/drawings but all I could find is these 2 pictures from our fellow member dd-ardwark (David?) http://rides.webshots.com/album/576679922NkjsGf
And a few figures on Richard Atwell's website, but nothing too helpful.
http://www.ratwell.com/technical/Exhaust.html

No problem. What ever I can do to help... ;)