My newly acquired 1974 Eldorado convertible project car

[MaR]

Next was to pad and upholster the sides.





The upholstery has a welt at the top edge and then another piece that folds over the staples to give it a seamless look.










The other side was the same as the first.

[MaR]

To finish the front lower section, I 3D printed a cap that fit over the lower part of the console. The cap was padded and upholstered to match.









I drilled mounting holes in the console and then fit the lower panel in place.

[MaR]

Now it was time to cover the section just above the lower panel. You can see this area when you open and close the front storage compartment so it needs to be covered. I made a template and cut out a piece of material.





I then glued it in place and reinstalled the lower front cover.

[MaR]

Now I could start trimming the inside of the front storage compartment. I started with a carpeted plate for the floor.





Next I 3D printed a rear cover plate and then upholstered it to match.







I then made side plates to cover the rest of the staples and finish the compartment trim.

[MaR]

The rear compartment was a bit easier to trim since it was just a box. I did the same as before: made a carpet plate and then made upholstered sidewalls to trim everything out.

[MaR]

Further back on the console I had to make a cover plate to hold the hinges for the rear compartment door and to retain the rear upper trim. I gave it the same profile as the armrests since it's at the same height and then double upholster it so it would be squishy but still firm like the door panels. The plate itself is 3D printed and it's mounted to a wood frame.









The hinges are a wraparound style and I painted them to match the upholstery.









The rear compartment door is plywood with a 3D printed "bump" for the latch. The latch is also 3D printed but it's printed out of metal.

[MaR]

Next I made a pattern for the rear compartment lid upholstery.







I then cut out the upholstery and sewed the corners.







Next I padded the rear compartment lid and then stapled the upholstery on.









I then attached it to the console and made a cover plate to hide the staples.

[MaR]

Now came the hard part: the front curved compartment lid.  It took several tries to get the shape right and to add all the features needed to mount, upholster, and attach the latch. Here is the final raw 3D printed part:







Here it is test fitted on the console with the 3D printed metal latch mounted.







Next I glued tack strips in the grooves on the inside so I could upholstery it.







And then I padded the door like the rear compartment door.

[MaR]

The upholstery for the front compartment door was a bit more complex than the rear door and had to be made out of several pieces sewn together. Here are the patterns.







With all the parts cut out, I sewed the pieces together, stapled them to the door, and then test fit the door.









Next was to made a trim plate for the inside of the door to hide the staples. I printed this part also so it would fit tight.

[MaR]

I then mounted the console back in the car so I could start work on the waterfall piece that goes between the upper parts of the rear seatbacks.





The factory style Talisman rear console had an upholstered waterfall that matched the seats.





I wanted something different and I decided that a waterfall that matched the style of the upper side panels and upper door panels would look good in a convertible. I first printed the waterfall piece.





Next I printed the stainless trim out of metal and then threaded the mounting studs.







Then I powder coated the part so it looked more like polished stainless.





Then I added a "wood" accent stripe like the other parts have.





I then put the "wood" on the printed waterfall and bolted the metal trim on.







And finally I popped the waterfall in place.

[MaR]

The other thing I worked on was what I called "The quest for quiet". The exhaust on this car was a mixture of original parts and poorly made aftermarket parts. The resonator was replaced with a piece of pipe and the factory muffler was rusted out. It sounded about as bad as you would expect it would. I had already replaced the muffler and added a replacement resonator with little change so now it was time to actually see what was wrong. I started out by making a new rear section. This piece had been replaced before and did not fit very well. I have never done any exhaust work before so I broke out the Hobart and got some mandrel bent pieces and started gluing parts together. Here is the rear section that was on the car. It goes from the muffler, over the rear axle beam, around the gas tank, and over to the resonator.







I bought some mandrel bent parts and started to test fit everything







After some adjustments, things seem to clear everything OK.









I don't claim to be a welder but I was able to stick things together relatively OK.

[MaR]

With the rear section all welded up, it fit well enough to not hit anything so I bolted it in.









After all of that, when I started it back up, it did not seem to make much of a difference. I was a bit annoyed but the section I replaced was crap and needed to go anyway so at least it was not wasted effort.

[MaR]

Forward of the muffler was a little jog in the mid pipe that was kind of crusty looking and not in the best shape. I found an aftermarket pre-bent part that was for a ~2000 Explorer with the right diameter and offset. I cut off what I needed and replaced the jog.









What I did not take a pic of but should have is what I found inside the jog. Back in the '70s when this car was made, Cadillac was using double walled exhaust pipes. There was no gap between the walls, the double walled construction was just there to make it thicker and a bit more quiet possibly? Inside the jog that I cut off, there was a big bubble sticking up in the bend where the inner wall puckered when it was bent. I really did not think much of it when I cut it off since I was removing it. A few days later when I was looking around to see if I could find something obvious for the persistent huge exhaust leak, I noticed what looked like a long dent on side the mid pipe. There was no way for anything to hit it there so I just cut it off to see what was going on. This is what I found inside:





That bulge was about an inch tall and was about 18" long. I did cut the pipe in half where the bulge was at and the metal was clean with zero rust at all so it had been that way most likely from the factory. I replaced the section of pipe and added an O2 bung in case I decide to add fuel injection.





With those obvious flaws fixed, I fired it up and...



No change at all in the sound. 

[MaR]

There was not much left of the factory exhaust at all and I spent a considerable amount of time fixing even the most tiny of pinhole leaks. I pulled the manifolds off and ground the mating surfaces for the heads to a perfect finish. I installed new graphite crush gaskets between the manifolds and the heads. I pressurized the system and checked and double checked every joint and there were zero leaks. I was left with only one other option: cut the y-pipe out. There is zero possibility to get the y-pipe out of the car in one piece. Even the factory service manual says to just cut it and replace it with a new one. There are aftermarket units but they don't look that great (small pipes with crush bends) and it looked a bit more complex than the other part that I had pieced together. Still though, I had no choice if I wanted to solve the issue so out came the angle grinder. I made sure to make marks so I could put it back together once it was out and I stated cutting.









Once it was out, this is what I found in the drivers side down pipe:





There was no indication of a problem on the outside of the pipe but almost half of the pipe was blocked up with that jagged bulge inside that pipe. It had never been apart before and all indication showed that it had been that was from the factory.

[MaR]

I actually piled all the part in the trunk of my other car and took it all to the closet Summit Racing store to get more mandrel bent parts. I mocked up the y-pipe on stands and started fitting parts.











And here is the finished Y-pipe. The only parts of the old exhaust system I reused were the bell flanges and the brackets to connect it to the manifolds.





The end result was positive. The noise I was trying to fix is now gone but the exhaust is now a bit leaky in places. I'm kind of tired of working on it right now though so I will fix that part in the near future. I have band clamps on it in places and I really need to get some weld on flanges or V-band clamps that will do a better job of sealing. Also, the little two to one Y that I'm using seems to be acting like a resonator a bit so I need to either wrap it or replace it with something without a chamber to quiet it down a bit more.

[MaR]

And that's it for right now. I'm doing more upholstery work at the moment and I'll have plenty more to post soon enough.

[The Tassie Devil(le)]

G'day Mitchel,

Thanks for all those lovely pictures, and especially for the ones showing the chipboard backing for the back of the rear seat.   This was the first time I had seen a virtually undamaged part.

If you thought yours was bad, mine was horrendous, but having a second one from a '71, allowed me to make up one out of two, then more modifications to fit my shoulder safety belts.

Bruce.

[David King (kz78hy)]

The interior and exhaust work is just amazing, you are a craftsmans craftsman.  That will be some car when complete.

[MaR]

G'day Mitchel,

Thanks for all those lovely pictures, and especially for the ones showing the chipboard backing for the back of the rear seat.   This was the first time I had seen a virtually undamaged part.

If you thought yours was bad, mine was horrendous, but having a second one from a '71, allowed me to make up one out of two, then more modifications to fit my shoulder safety belts.

Bruce.

If you ever need more pictures of it, just let me know. I have a ton.

[James Landi]

Mitchell,

It's extraordinary that you're uncovering design and manufacturing errors that occurred nearly half a century ago! Loving your rear seat treatment, and very much looking forward to seeing the entire seating arrangement once you've completed it   Also, in your narrative, you mention "setting aside" frustrating challenges, like that exhaust system, and leaving it for another day--- a great approach!  I owned a '67 Eldorado back in the early 70 (through 85)... It was a durable daily driver, and my commute was 90 a day.  One day both exhaust pipes (having rusted through) fell, got caught up in the highway surface and ripped off the entire system.... did not make it to work that day.    Keep us in the loop with your wonderful narratives and pictures--- James