Installing Exhaust Flanges
 

I'm sure this is by no means the only way to so this, but this is how my
buddy and I did it. I could not find another thread on how to change slip on pipes to flange, so hopefully this will help someone in the future.

The 1st step was to remove the side pipe from the header.
Remove tension springs from header, and work pipe hanger off rubber boot
from side of car.(spray 9 or windex helps)

Measure 1 flange width down and mark the 4 collector tubes on the side pipe
(about 3/8") this will be cut off. We used a port-a-band which gave each
pipe a nice even and straight cut. Then used a Dremel and files to remove
all burrs.

Install flange over collector tubes of cut side pipe. This was not easy! Had to
use flat head screw drivers between tubes to bend them apart, while
using a rubber hammer to bang the flange on the pipe. Removing the burrs
makes this process a lot easier. Since welding from the inside, flange
should be flush with the pipe.
http://i189.photobucket.com/albums/z...oretacking.jpg

Weld flange to the pipe. Use an angle grinder to remove excess weld slag from flange. We also used a sand paper wheel for the fines and to get
extra smoothness across flange. This will also show any gaps that might need more weld.
http://i189.photobucket.com/albums/z...roughgrind.jpg

For extra strength, we ran some beeds on the outside of the flange around the pipes as much as possible. Couldn't get in between the collector
tubes with the type of welder we had.

Then bolted together the loose flange to the welded one. Slipped flanges and pipe onto header and made sure pipe was in the exact location
along the car for finished look.
http://i189.photobucket.com/albums/z...allignment.jpg
http://i189.photobucket.com/albums/z...fortacking.jpg

Then tacked header flange to header. Protect your car! With coated headers
sparks will fly while tacking. Unbolt flanges and remove side pipe.

Next, remove header from motor. For the driver side, I had to remove the
steering column to get to the header bolts.
http://i189.photobucket.com/albums/z...columnassy.jpg
http://i189.photobucket.com/albums/z...houtcolumn.jpg
At this point it was discovered 2 of the crimp points on the header had holes in them when they were orginally bent for the side pipes.
Filled them using the welder.
http://i189.photobucket.com/albums/z...Crimpholes.jpg

With the port-a-band we cut the excess header pipe off flush with the flange.
http://i189.photobucket.com/albums/z...n24/Tacked.jpg
http://i189.photobucket.com/albums/z...xtracutoff.jpg

Then cut small pieces of header pipe excess, to fill around the headers in flange for less welding.

http://i189.photobucket.com/albums/z...withfiller.jpg

Welded flange to header using the same process as with the side pipe.
http://i189.photobucket.com/albums/z...Insideweld.jpg

Grind smooth, check welds, and weld the outside of the headers for added
strength.
http://i189.photobucket.com/albums/z...utsideweld.jpg

Install header on motor.
I used hi temp gasket sealer on header gaskets as well as flange gaskets.
Connected flanges together using grade 8 bolts and lock washers.
http://i189.photobucket.com/albums/z...hedproduct.jpg
http://i189.photobucket.com/albums/z...ewfinished.jpg

Installing the flange kit made a huge difference in how the engine sounded. Exhaust actually comes out the pipes instead of blowing carbon all
over the engine compartment. I don't get choked by fumes when sitting still, and the car doesn't back fire anymore.
It actually sounds like a Cobra! :D
The whole job took 2 of us about 10hrs.

I just want to thank Tony for all the work and help he gave me with this project. Couldn't have done it without his expertise and tools. :)

Also posted on www.backdraftboys.com

Ned,
Fantastic how-to. It's a big project that you made look so easy %/ A great contribution to the Backdraft community.

Nice info here..is this a common problem with the cars that everyone has to deal with or is this hit or miss depending on application?

Thanks Troop

I think most everyone that has these slip on side pipes has at least some exhaust blow back. It seems that they have tried to seal it up one way or another. Of course the only true seal are flanges with gaskets.
Pain in the a$$ because foot boxes are close to the engine and not a lot of room to work. I'm glad now that I bought a Cobra with a SB.

Cobra_Troop,
FYI the flanges are standard on the cars now. There was a short run several years ago where the slip ons were used by customer demand, of course the demand changed when the weakness of slip fits became known.

Thanks Jay,
I think the biggest pain with this project, was removing the header bolts.
Something that easy takes too much time for me.
Need that special little tool, or just take the bends out of the headers.:eek:

good info thanks guys...Jay I get more impressed with the car the more I read about how you guys continue to improve !!

Since I am all alone here, don't have the tools or the skills, and don't know anyone that does, I'm just sad. No, I am not angry.

I wish I had waited for #239 instead of #139, but, HEY!

#000 steel wool, packed in with a 1/4" dowel, then dogged down with a large radiator hose clamp, will last long enough for a car show.

If necessity is the mother of invention, then desperation has to be the father.

I have a log of all the little problems Gunrack has and that have been fixed, mostly to frighten off potential buyers.

Yeah, she is for sale, but...

I still have a BDR Cobra in the garage, flaws and all.

UT