Engine Bay Tear Down
The first thing was documenting the engine bay configuration so I'll be able to identify the locations of hooks, clamps, brackets, hose and wire routes, etc.
First I removed the wiring harness because it's attached to so many other things. I removed the junction box last and saved the harness for reference and cannibalization of plugs. I also saved the loom clips.
Next I removed the firewall and interior heater boxes. Over time, the sealant had dissolved into a very thick ooze. I'm converting to air conditioning, so didn't inspect the boxes.
The steering column was next. The mounting nus are in the interior and the column reinforcement plate (shown) is removed from the engine bay . Two support bolts under the dash are removed and the steering wheel column pulls out. Since this is getting rebuilt, I didn't inspect it.
Fourth was the vacuum booster. It was difficult because it's attached to the pedal assembly. Remove the pin from the booster fork and four bolts (three shown). Remove the two bottom bolts first, then loosen the top ones until they are nearly off. This keeps the booster from falling on the floor. From the engine bay, you can reach these through the hole left by the steering column. I'm replacing the booster, so I didn't inspect it.
To take out the pedal assembly, there are additional fasteners and brackets that must be removed from under the dashboard.
I'm including the cowl with the engine bay upgrade, so I removed the wiper system next. The washer fluid reservoir was removed from its bracket, the wiper arms were removed from their rotation points, the motor was disconnected from the wiper transmission, and the wiper transmission was removed from the base plates (three bolts per plate). The base plates consist of two pieces, one one the cowl with mounting studs, and a reinforcement on the interior side of the cowl. These are held together with four nuts (lower picture). After removing the nuts, I used a heat gun to loosen the sealant and pry the plate off. I'm restoring the wiper system in a separate walk through so didn't inspect anything at this time.
Finally I was left with the "odds and ends": charcoal filter, radiator overflow tank, hood latches, etc. Then out came the firewall plugs and seals. With a screwdriver and needle nose, I removed the dust seals at the top, front, and bottom of the fender skirts. Finally I removed the remnants of the dust flap from the control arms tunnels in the fender skirts.
Lastly were brackets and clips. These were attached by various means from soft aluminum body rivets to adhesive. I carefully drilled out the rivets (3/16" bit) and used a heat gun on and putty knife on adhesive. This is a lot of work, as there are many brackets, clips, hooks, etc., fastened to the engine bay.
On the 79, the headlight header bar is glued to the surround, without bonding strips and rivets. My header bar was so rusty that I could pull it free with my hands after it was unbolted from the end brackets. It was by far the worst thing I removed from the engine bay, and it had some other problems I'll get to later in this walk through.
The front bumper cover support bracket was riveted AND glued. It was not easy to remove. I included this picture to show the combination of rivet holes and glue. It was the glue under the head light window that made removal challenging.
I inspected all the braces, brackets, hooks, etc. They all needed new paint, but none needed replacing.
I was very lucky. All the components, brackets, hooks, etc. I removed and inspected seemed salvageable. There was minor rust in some cases, and everything needed refinishing, but the only piece I was concerned about was the headlight header bar. The stripped down engine bay is shown.
Engine Bay Repair
With hardware removed, stripping and inspection could begin. I used sandpaper, acetone, heat and a wire brush to remove paint, glue, sealant, and dirt. I also stripped the fender wells. After many hours, I was down to the bare SMC. I found four things needing repair:
To keep this page short, I linked the repairs above to separate pages, but they are not considered separate projects. Roll cursor over picture for caption and click the picture for the repair walk through. The picture opos up on the screen and the link is in the lower right corner.
Engine Bay Painting & Assembly
With repairs complete, it was time to start putting the engine bay back in shape. I started with epoxy primer to seal the SMC. Then I taped off the areas in the front where adhesive would be used so the header bar and bumper cover support bracket would bond directly to the primer.
Next I applied thermal paint to the firewall using foam rollers and brushes. This was applied directly to the primer. It has a 45 day cure time before top coat, so I didn't get the firewall completed before the cold weather set in. The paint texture is caused by the ceramic spheres, which were like sand in the paint. The paint was very thick and didn't run when reasonably applied. I waited a day or so between coats. These pictures were taken after the fifth and final coat.
I wanted to get as much finished as I could, so I alternated between painting the firewall and putting rubberized undercoating in the fender wells. Each fender well got three coats.
After the fifth coat on the firewall had cured for a week, I masked off the fender wells and sprayed the engine bay with machine grey acrylic enamel paint. I'm a novice painter and the job certainly wasn't perfect, but I learned a lot in the process. I'll paint the firewall this spring.
I sand powder coated all the brackets to protect them from further rust. There were many rubber coated hooks and clamps. I used a propane torch to remove the old rubber, powder coated, and dipped them three times in black plasti-dip. They came out looking new. Unfortunately, the picture doesn't illustrate that very well.
The next step was installing brackets. I used the original style body rivets and cut the tip off an air hammer attachment to make a flat contact surface. I set the pressure at 20 psi and set the rivet by placing the hammer against the head while a friend held the buck bar against the stem. I used a 1 lb hammer head and it worked just fine. This blurry picture will get replaced this spring, but it does give a sense of what the finished engine compartment looks like.
To finish work for the summer, I installed the front bumper cover brackets using SEM 39747 adhesive and bevel headed stainless pop rivets. Similar to the header bar, I taped off the adhesive contact area before painting. I used a popsicle stick to cover the bare metal with adhesive. After riveting in place, I used clamps to hold the SMC against the adhesive surface.
That's it for now. When spring time rolls around, I'll paint the firewall and finish the bracket and seal installation.
Engine Bay & Firewall
This was my 2015 summer project I nearly completed on schedule. It included the air conditioning retrofit project, which took longer than estimated. Documenting this in sequential fashion is difficult because there is no standard path to completion. Damage, corrosion, and other findings result in "side projects" not worthy of a dedicated page. These are covered here and result in a long walk through of small, unrelated tasks converging towards a finished engine bay. If you do this, you will likely have side projects not covered here. As with other projects on this car, there were some things to think about.
FIBERGLASS PROTECTION: I've read that bare fiberglass, including SMC, oxidizes. After some research, I decided on epoxy primer as a protective coating over the bare SMC. This is great stuff because it sticks to SMC, and everything else (paint, epoxy resin, body filler, etc.) sticks to it. It should make a great base to work from.
HEAT MANAGEMENT: I've read numerous posts on how warm a Stingray cabin gets after the car has been running a while, even with a/c. Since my car had no a/c, I have no basis beyond others' experiences. Since I'm going through the trouble to install a/c, I want to reduce as much heat migration from the engine bay as possible. While there are things you can do to the interior, the focus here is engine bay improvements.
I am intrigued by the ceramic micro-sphere paints I read about. They seem a reasonable way to reduce or prevent firewall heat soak. These paints use very small, hollow ceramic spheres to retard heat transfer across the surface they are applied to. I don't know that these products live up to their web page claims, but forum members have done backyard experiments to determine their effectiveness. While certainly not "scientific", they are probably accurate regarding how the product is used in the car restoration community. What sold me was a post, with pictures, showing a member holding a metal bar with bare hands while applying a propane flame to the other end. The bar was half covered in several coats of this paint. This is one of the reasons I like the forums. This guy had no agenda beyond seeing how well these products work and sharing his results. As for me, I don't know how much "heat reduction" or "R-value" his paint claimed to have, but if it stops that kind of heat, it's a step in the right direction.
After looking at several products, I chose Hy-tech Metal Shield #1267 paint. On bare fiberglass, they recommend SC #1000, but I also plan to coat the transmission tunnel and floor pans and wanted to use one product. Their techs confirmed that though 1267 is a direct-to-metal paint, it bonds with epoxy primer. I plan to coat the firewall with this product, and the blower and evaporator boxes as well.
WIRING: Wiring is an issue with my car. The wires are stiff, the insulation cracked, and terminals corroded. I'm still researching options but leaning towards an aftermarket set-up such as those offered by Painless. The factory correct harnesses are very spendy at about $1,600 for the entire car. While I'm sure they are a breeze to install, I personally can only justify that cost for a factory correct restoration on a show car. I'm very handy with crimpers and a soldering iron, and it's very frustrating that I cannot buy the individual components to create my own wiring harness. Obviously someone sells them since factory correct harnesses are offered by multiple vendors.
PAINT: Stingrays came from the factory with blackout casually sprayed inside the engine bay. From what I can tell, it was applied directly to the SMC. For a factory correct look, I could go and get a few rattle cans of flat black and spray it somewhat randomly in the engine bay. However, I've decided to go with something a little more unusual, and will be top coating the SMC with a dark machine grey acrylic enamel. It should go nicely with the satin black I've chosen for the brackets. I'll be powder coating most metal parts.