I’ve been working on the exhaust for the past couple of afternoons and I’ve been able to make some pretty good progress. I would say that I’m somewhere between 1/2 and 2/3 of the way finished the exhaust fabrication.
On Tuesday I created the complex pipe routing that goes from the exhaust tips, around the trunk pan and over the solid rear axle. This was some pretty crazy time intensive work and I spent a lot of my time laying on my back staring up into the chassis looking for the best route.
There’s lots of things to be aware of such as clearing the top most travel of the axle, spacing on both sides of the axle when it travels up and down, not getting too close to the air bags, not getting too close to the shocks, and clearing the upper trailing arms through their full travel.. Yikes 😦
The final results of the rear exhaust routing can be seen in the picture at the top of this post. I also made sure that as I went along there were enough areas where I could use an exhaust clamp and pull the exhaust back apart and reassemble it in sections. This will allow me to remove the exhaust at any time that I like without having to cut it off. Below you can see the nice spacing I have when the axle is at its top most position and at its bottom most position.
Then yesterday I started modifying the driver’s side header to tip it further away from the engine. There are a couple of sensor plugs on the block of the engine that were being covered by the bottom of the header. This was the same procedure that I did earlier on the passenger side.
Next was making a few modifications to move the oxygen sensor bung and inserting both the flex section and catalytic converter. The flex section gives a little more play on the exhaust and helps reduce stress on both the bolts and welds of the system. Even though the engine is on solid engine mounts, I still like to have some extra give in the exhaust.
Finishing the front of the driver’s side allowed me to prop up the rear of the rectangle exhaust pipe in the rear in order to to mock-up and tack weld the rear section connecting the side pipe to the muffler and then onward to the rear loops going over the axle.
The side exhaust pipes are 2″ x 3″ rectangle tube that runs right under the frame rail of the car. This allows the exhaust to be tucked up under the frame and not seen from the outside since the body shell overlaps the frame. Unfortunately that does mean creating rectangle to 2.5″ round tube connections.
Since I had a bunch of height under the rear cabin I could tilt the muffler up on its side so that it had a straight shot to the rear loops over the axle. Again, these were positioned so that they would not be lower than the outside edge of the body shell.
To finish up the driver’s side I need to weld on the hangers to ensure that everything stays where it’s supposed to. Once that’s complete I can finish off the welding for all of the areas that were temporarily tack welded as I was mocking the system up.
The final bit will be hanging the passenger side tubes and rear muffler and then it will be on to priming, seam sealing and painting the bottom of the chassis 🙂
As you can see, the rear axle needs a lot of rust clean-up work and the driveshaft will be sent out and a new one will be created to replace it.