Imperial Journey

With the new speaker installed in the dash the next job was hooking up all the wiring. RetroSound makes this easier with a two part harness: they have a short harness that plugs into the radio and the main harness plugs into. This means that you have a visible plug to connect to when the radio is installed rather than trying to find a multi-wire connector by braille buried deep in the dash on the back of the radio.

Connect the four speaker wires and then connect switched and unswitched power. Unlike the factory radio, modern radios have a continuous power connection and use switched power to turn the radio on and “off”. There isn’t actually an off, just a (very) low power mode. These connections were easy since there are several open circuits for both switched and unswitched power in the new fuse block. There are even short leads already connected! Add MetriPack connectors to the radio harness and plug them into the connectors already available from the fusebox. Connect ground and we are ready to go!

Mount the radio in the dash, including front and rear supports and tighten securely. Plug the wiring harness into the radio. Sit back for a moment and admire how it looks!

Turn on the radio and listen to sounds of silence…

Oh, right, have to turn the car on! Turn the ignition to accessory and hit the power button again. This time I’m rewarded with the RetroSound boot screen – but still no sound. Try tuning the radio and listen to the dulcet sounds of an FM radio station. Try several other stations – good reception and sounds good.

And there was much rejoicing!

The last thing to do was grab the user manual and set up the radio. Adjust bass and treble and sync to phone. I now have hands free telephone in the Imperial as well as streaming music. Figure out how to set the time – I now have a clock in the car!

Everything works. People that don’t know it isn’t the factory radio won’t notice anything. I’m going to declare this a success!

Once the filler plate was installed on the radio a bit of fiddling was needed to adjust the width and depth of the volume and tuner shafts. The RetroSound adjustable mounting brackets supported these adjustments, producing a good fit.

Support at the rear of the radio was provided by a custom bracket that picked up the support from the original factory radio. This was the second project where I’ve used the bench shear – this is so much better than tin snips or a cutting wheel on an angle grinder for working with sheet metal!

With mounting resolved the next step is the electrical connections. The supplied wiring harness makes this job straightforward. Except for one tiny little detail…

The radio is designed for four speakers: front left and right and rear left and right. I have left and right rear speakers. And a single center speaker in the front…

Most cars through the 1970’s had a single speaker in the middle of the dash. Stereo wasn’t a concern. Nor, to be fair, was audiophile quality. The 1963 Imperial was one of the earlier cars to have a transistor radio instead of a vacuum tube radio. It’s amazing that (when working) these cars can actually receive modern radio transmissions!

The common approach when installing a new stereo is to mount new speakers in the kick panels or the front doors. There is no way I’m going to cut up my new door cards! And there isn’t enough room in the kick panels. Or under the dash.

I’ve been wrestling with this problem for a while. Maybe just set the front balance to completely left or right? I can’t be the first person with this problem. Time to fire up the Google!

Would you look at that: stereo speakers are available! In this case a stereo speaker is a single speaker that produces stereo sound. It has left and right inputs. A single bass cone since bass is non-directional. And two mid range/tweeter voice coils for separate left and right. Probably not great stereo imaging, but it looks like these would work.

And, big surprise, RetroSound offers them. I wish I’d know about this when I placed the original order. Hop on the InterWebs and get another order in.

I have to replace the replacement speaker I installed in the center of the dash a couple of years ago. But that is a small price to pay for a clean solution.

A box from RetroSound showed up. Schlep it out to the workshop. Remove the old radio. Dig out the RetroSound bezel and carefully unwrap it. Do a trial fit to see if it goes in the dash cutout.

It fits! It is an absolutely perfect fit vertically – just a few thousands of an inch clearance up and down. Horizontally it is about 3″ narrower than the cutout. Further checking shows that the volume and tuning knobs will fit, thanks to the RetroSound mounting system. The new radio is about 1/4 the size of the factory radio so there is plenty of clearance around it. The new radio will fit. The only question is can I make it look good?

I have the height and width of the dash cutout. I have the height and width of the new radio bezel. Now, what about the curved dash?

If I’m lucky it will be a circular curve. Mark out half circles on cardboard at 2″, 2-1/4″, 2-1/2″, 2-3/4″ and 3″ and cut them out. Test fit them against the dash. Huh, the 2-1/2 is an almost perfect fit.

Using the trim piece that came with the bezel for inspiration, design a wider trim piece. This is still flat, but is a starting point to figure out how things fit together. Print it out and try it. It fits into the dash cutout, which is a good start. It fits the radio bezel horizontally but not vertically. Doh! – I made the cutout 1.500″ tall instead of the needed 1.540″. Dumb mistake, easily corrected.

But the part wasn’t well designed for 3D printing. It included a spacer which was narrower than the trim piece. This required extensive supports to print. The slicer handles this easily, but it wastes a lot of material. For the next iteration remove the spacer, leaving a full width flat bottom flange – perfect for 3D printing. I’ll make the spacer as a separate part when I determine how thick it needs to be.

Make these adjustments and print out V2. This fits both the dash cutout and the radio bezel. Since it is flat it doesn’t fit snugly against the back of the dash.

Version 3 introduces the curved flange to fit against the back of the dash. The raised blocks on each end don’t stick out far enough, so they need to be at least 1/8″ taller. The blocks on each end don’t need to be solid. To reduce the amount of material used make pockets in the back of them.

Version 4 almost fits well – there are some tabs and doubled areas in the dash structure that stick out. Make cutouts to provide clearance around them.

Version 5 actually fit quite well. It fit the cutout in the dash, the curved flange fit snugly against the back of the dash, and it fits the radio bezel tightly.

Version 6 was a slight cleanup: fillet some visible edges so they look better and modify the material saving pockets inside the blocks to remove even more material. So far all of the test parts have been printed in PLA which is the cheapest filament available. PLA apparently doesn’t hold up well in the heat of a car interior, so switch the filament to ASA (a high strength engineering plastic) and print the hopefully “final” part.

Why didn’t I get the design right the first time? As I’ve mentioned before, engineering design is an incremental process. You create something simple as a starting point and then modify and refine it. With traditional techniques you typically create a prototype and then modify it until it works. With CAD and 3D printing you make changes in CAD and then print out a whole new part. This makes the intermediate changes more visible. In this case each part took about an hour to print out and cost less than $0.50 in materials.

It would have been hard for me to make a part which this quality of fit using traditional techniques. In my past life I probably would have used a piece of 1/4″ black foam as a filler between the radio and the dash cutout and lived with it. I like the new approach better!

There is another alternative for radios: RetroSound makes a line of modular radios designed to go in old cars. They do this by providing a radio body (which they call a motor), a set of bezels that contain the display and UI, knobs, and a large collection of faceplates to fit a wide range of cars. The radio itself is quite small and uses a very flexible mounting system allowing it to be installed in as many places as possible.

All you need to do is find your vehicle listed and order the proper motor, bezel, faceplate, and knobs. Easy!

Of course they do not have a listing for a 1963 Imperial.

What they do have is detailed dimensions for all of their products. Almost like they understand their target market! After extensive study I found a bezel that looked like it would fit: it was exactly the height of the Imperial cutout and narrower. There was also a faceplate that made the bezel wider but no higher.

OK, this looks like it would fit into the cutout – but how to fill out the hole and make it look decent?

Just a minute – what about 3D printing??? I think my CAD skills have improved to the point where I can do this. Well, one way to find out! Let’s get an order placed.

RetroSound has a choice of three “motors” that are all the same size and come with differing power output and feature sets. I decided that the lowest level Motor 1B would meet my needs. In addition to AM and FM it supports Bluetooth for hands free calling and music streaming. It is the cheapest option, has everything I really need, and is a massive upgrade over what I have now.

Add in the bezel and faceplate that look like they should fit as well as a set of period correct knobs. At this point the cost is around $250. If I can make it work it will be well worth it!

If I want tunes in the Imperial the current radio has to go. There are several ways to do this.

The cleanest approach would be to get another 1963 Imperial radio. A working one one be expensive. And this still leaves you with 60+ year old technology and components.

Since this is a common problem there are companies that take the old factory radios and replace the electronics inside with new technology. There is a fairly small board available that contains all of the electronics for a modern radio and replaces the factory pieces. The factory knobs and display are retained. The result is a completely stock appearance with new technology – including Bluetooth and USB. This is tempting. Unfortunately the current radio is too badly damaged for them to work with. I would have to get another 1963 Imperial radio to send to them for conversion. Which would get expensive quickly.

One popular approach in classic cars is to simply add a new radio. Many people hide the new radio, commonly in the glove compartment or under a seat. You also see them hung under the dash.

I’ve been seriously considering building a center console that would include a radio, cupholders, at least one USB power point, and perhaps some additional gauges. I’m confident enough in my sewing and fabrication skills to be comfortable tackling this job. The biggest downside is that it would reduce the capacity of the car from six people to five people. But this isn’t really a big deal.

Finally, you can install a new radio in place of the factory radio. In many cases this is easy: You can find a radio that fits the stock cutout. My 1976 Datsun 280Z used DIN mounting which made this a slip-in fit. Or you can enlarge the stock cutout to fit like I did in a 1968 F-350.

A common theme is that these vehicles had a flat surface where the radio fit. You could do whatever hackery was needed to make the radio fit and then hide the evidence behind a radio faceplate.

Of course the Imperial is special. The radio is a non-standard size. And the dash is tightly curved where the radio fits. No modern radio will fit without ugly dashboard surgery.

I chose the Imperial because of its character. Throughout the restoration I’ve tried to make functional upgrades without changing the appearance of the car. To include modern technology as invisibly as possible.

Any radio upgrades should preserve both factory appearance and provide decent ergonomics. Appearance rules out hanging a radio under the dash. Ergonomics rules out a radio in the glove compartment or under the seat. Economics makes doing anything with the factory radio a challenge.

What to do, what to do….

Time to upgrade the Imperial radio. Before talking about the new radio and the overly complex installation process let’s take a minute to look at the “original” radio. Once again I would really like to know more about the history of this car!

The radio barely worked when I got the car and doesn’t work at all now. It’s worth spending a moment on how bad it is.

The Imperial has a custom dash cutout for the radio, so only the factory radio fits. Someone had drastically modified the radio. Some of the evidence was obvious – the wires coming out of the radio were modern wires with modern labels. But the extent of changes weren’t clear until examining the guts of the radio.

Start with the outside: The case has been cut in several places. No idea why. The factory antenna connector is empty. The actual antenna connection is an inch or so inside the case, accessed through a badly gouged hole in the case. Speaker and power wiring go through a hole in the case with no protection. Not a good starting point!

Inside the case gets even worse.

The factory circuit board has been replaced with something else – no idea where it came from or what the specs are. Even worse about 2/3 of this new circuit board has been cut away to provide clearance for the factory tuner and pushbutton assembly. This new circuit board is very crudely mounted to the case.

The tuner pushbuttons don’t do anything – their operating mechanisms have been removed. When I got the car the tuner knob would move over about half the radio band; now it doesn’t move at all.

The volume control is connected to the volume knob with a piece of rubber hose and hose clamps. Admittedly this is a flexible connection, but still…

I suspect that the original radio died and someone took a cheap aftermarket radio and hacked it up so that it “fit”. I’ll give them credit for creativity in concept and negative points for quality of execution. I’m impressed that they were able to make it work and appalled at how they did it.

There is nothing to salvage from this radio. The case has been cut up in multiple places. The remnants of factory components have been pretty well destroyed. About the only thing you can say for this radio is that it still does a good job of filling the hole in the dash!

With the jack ready to go there was a gas tank that needed to be dropped! It is a lot easier to handle an empty gas tank. And this replacement tank has a drain fitting. The gas gauge is reading empty, so slide a pan under the tank and empty out the “couple of gallons” of gas left in the tank.

Yeah, about that… I drained 6 gallons of gas out of the tank – basically a quarter of a tank. You may remember a mention many posts back of a Meter Match box that adjusts gauges so that they read correctly. I had ordered one. Now is clearly the time to install it!

The empty gas tank came out easily on the new jack frame. It didn’t wobble or fall – just stayed in place while I removed the supporting straps and wheeled the jack out from under the car.

Toss the gas tank up on the workbench and study the problem.

There are two holes in the gas tank: one for the filler neck and one for the gas pickup and sender. I suspect both of them, so will fix both of them.

The sender has a rubber gasket – a fairly flimsy rubber gasket. This had leaked before and I fixed it with gasket sealer. This time I ordered special fuel resistant gasket sealer – specifically Permatex 29132 MotoSeal. I also ordered several sheets of different kinds of gasket material to make custom gaskets. I ended up using 1/16″ thick Nitrile rubber – thicker than the original gasket. Trace the old gasket onto the rubber sheet, cut it out, and test fit it. Hmm, the locking ring doesn’t clamp down securely… Could this be part of the problem?

Cut out another gasket and test fit with two gaskets. This time the locking ring locks in place securely. Liberally coat all mating surfaces – including between the two rubber gaskets – with the gasket sealer, re-assemble, and tighten the locking ring securely. Out of paranoia add more gasket sealer over the entire assembly. This will be a nightmare if I ever need to take it apart but should now be leak free for life!

The filler neck needed more work. It is a separate pipe that slips into the gas tank and is sealed with an O-ring. I had dented it during a previous when the jack slipped. I rounded it out as well as I could, but may not have gotten it absolutely circular.

Considering this problem, I recalled that I had a tailpipe expander. These do a poor job of actually expanding a tailpipe, but they do a great job of making it round. After a few minutes of searching I was able to find it. Amazingly the smallest adapter actually fit inside the filler pipe! Clamp the assembly in the vise and crank down the adjuster bolt. And the filler now seems completely round.

While this was a good step I still didn’t completely trust it – so the filler pipe was re-installed in the gas tank with a liberal coating of gasket sealer.

That should take care of any potential leaks.

Plop the gas tank back on the jack and slide it under the car. Carefully raise it into position and secure the mounting straps. This was much easier than the last time I wrestled the gas tank!

Secure the fuel line to the gas tank and reconnect the sender wire. Everything should be ready to go.