Detailing Your Muscle Car Engine Compartment

The Finishing Touch

GM A-body engine compartment detailing

Story and photography by Jim McGowan

A clean and detailed engine compartment is the finishing touch for any muscle car restoration. Once you reach this stage, regular cleaning and dusting will keep it looking great for years to come.

While your engine is being rebuilt or detailed out of the car, it’s the perfect time to clean the engine compartment and replace any worn out parts.

The 1964 through early ’70s GM engine compartments are almost identical, with the only changes being factory options like power steering, etc. This restoration process should take place only after your car has been painted and rubbed out. Waiting will eliminate overspray from ruining your detail work. Regardless of how sealed up you think the area is, exterior paint will always somehow find a way in.

Since this engine compartment is partially restored already, I will show you the highlights of how to do the clean up and the products you can use to bring the parts back to a clean factory look. The subject of this exercise is a ’65 GTO, and until this clean up, the engine had never been out of the car.

I prefer to do the work according to a plan: I begin by removing everything that is in the way of cleaning and sanding, which turns out to be almost everything in sight. Take pictures for future reference and strip it clean. In this case, I’m taking the precaution of changing the original engine and lighting harnesses with new ones. If possible, a light pressure wash works wonders; if not, then you can clean as you go. I usually start at the core support and work my way around the complete area in a clockwise direction.

A word of caution! Most aerosol paints don’t like temperatures below 70 degrees. If it’s too cold the paint can fisheye. So if you’re working during the winter, a heated garage is required … or you can always convince your wife to turn an empty bedroom into a paint booth, or … aah … maybe not!

The complete compartment was finished and most of the parts were replaced before the engine was reinstalled. Make sure all the parts and areas that are difficult to get at are cleaned or installed before the bullet gets loaded. This is a project that can take a few weeks of working a few hours a day, so patience is required. To make the work flow smoothly, try to accumulate all the supplies you’ll need prior to starting. All the time and effort will be worthwhile when the project is finished and you pop the hood at the next car show.

What You’ll Need:

• Rubber gloves

• Brake parts cleaner

• Eastwood (or equivalent)

paints as shown

• Green and brown Scotchbrite

pads (about 5 each)

• Normal array of hand tools

• 0000-grade steel wool

• A good spray-on household

cleaner like Simple Green

• A large drip tray for the floor

• A few small wire brushes

• An electric wire wheel if

possible

• Masking tape and masking

paper (newspaper works)

• Small Ziploc bags

• About 70 hours of free time

1 Since the engine and transmission had never been removed before, all the inaccessible areas were pretty grungy. Give the entire area a good overall cleaning before starting on individual sections.

2 We began by stripping off all the firewall parts. The radiator and all the other components had already been removed to get the engine out. Each part will be cleaned and properly detailed and all small parts, including nuts and bolts, will be bagged and labeled. This will make the reinstallation much easier. Even after a few weeks, it is sometimes difficult to remember where everything goes!

3 For safety’s sake, we decided to replace the decades-old wiring harnesses with exact replacements. They simply unplug at the firewall and have the right color wires and correct factory connectors.

4 The new engine harness is at the top, and while it can look intimidating the change out is easy and the connectors self-explanatory. The original harnesses, while intact, were dry and brittle from age and heat. Just work on one lead at a time and you’ll do fine.

5 The upper control arms are a mess. Clean them with Simple Green and a Scotchbrite pad and rinse with water. Then work your way along the frame rails and cross member. The original front brake lines have been removed from the distribution block and will be replaced with stainless steel lines from Classic Tube.

6 Here’s how the finished control arms should look. Remove each nut or bolt separately, clean on a wire wheel and paint. Then replace and do the next one. This way the whole assembly stays tight. If you want to replace the large silver washers on the early models, they are GM #0978-5742. Or wire wheel your originals and paint with Eastwood’s Silver Cad.

7 After all the surface dirt has been removed, sand the inner fender wells, frame, firewall, etc., with a green Scotchbrite pad, which is fine enough to not leave scratches, but coarse enough to provide a good surface for the new paint to bind to. If the surface is chipped, use 3M 400-grit wet/dry paper to feather out the edges.

8 Eastwood has the correct semi-gloss paint for the engine compartment, called Under Hood Black. Their trigger handle makes applying the paint a lot easier. Several light, misted coats will work better than one heavy coat, and won’t run. Spray about 10 to 12 inches from the surface.

9 I’m working around from the passenger side across the firewall. Wire wheel and clear coat every bolt head. Unbolt the metal parts near the trans tunnel and wire brush them to bare metal and then clear coat them. We’re installing new ground straps from. At this point, we’re working in the area to the right of the power booster mounting point.

10 Under the battery tray, we found normal surface rust caused by battery acid fumes over the years. Use 60-grit paper and sand to bare metal. Rust never sleeps, so get it all. Using a dust particle mask is recommended while doing this type of sanding.

11 Once the rust is removed, we painted the area with Eastwood Corroless rust stabilizer to etch into the metal. Let the first coat dry, give it a light sanding and apply another heavier coat. After sanding the second coat you can cover the area in Under Hood Black.

12 We used Justice Brothers Brake Parts Cleaner to thoroughly clean the connecting link and other steering parts. Then remove, wire wheel and clear coat each nut. Paint all the parts with Under Hood Black and reinstall with new cotter pins.

13 Here are the results of detailing the passenger side. The gloss is not quite as intense as it appears here. The fluorescent garage lights make it look shinier. All the hard work is starting to pay off.

14 Use Under Hood Black on all the steering components. Clean the parts that should be natural metal and clear coat them.

15 After cleaning the aluminum steering box cover, brush each bolt head until the original plating comes through, then apply clear coat.

16 New stainless steel brake lines from Classic Tube are now installed. We reused the original tubing retaining clips across the cross member.

17 We’re installing reproduction control arm covers and staples. We’ll use the original staple holes for authenticity. Tape the cover in position and locate the set of holes closest to the middle. Carefully drill holes through the cover matching the holes in the metal. Push the staple through the holes and have an assistant flatten the staple legs from the other side of the fender well. While this sounds difficult, it’s actually easy.

18 The finished covers take about an hour to install with a helper. Here you can also see the cleaned brake fluid distribution block and the stainless steel brake line going up to the master cylinder.

19 Small parts, like this original under hood light, should be cleaned, scuffed with a green pad, and repainted. The factory used the same hue of black throughout the engine compartment. For weird shaped parts, use wire clothes hangers to make hooks, and paint them while they are hanging.

20 The windshield wiper motor and voltage regulator are the only gloss black painted parts in the compartment.

21 For parts that originally had a cadmium finish, use Eastwood’s Silver Cad paint. It’s mostly clear, so shake it well and apply several light coats until the proper color is achieved.

22 The front core support bolt and washer were wire wheeled and painted with Eastwood’s Aluminum finish and then clear coated. A new fender well-to-frame ground strap was installed.

23 Little parts, like the correct battery cable and wiring harness retainers, make a great difference. They are available from most restoration suppliers.

24 Here’s the almost-finished engine compartment. Most of the original parts have been restored and replaced. Once the engine is installed, all the various wires, etc. will be connected. Note the engine wiring and ground strap at the firewall.

25 The engine and transmission are now back home and all the surrounding parts can be installed and connected. This engine has been blueprinted and built to Ram Air IV specs. It should be a good runner.

26 Detailing brackets and large parts is important to the finished product. This very early ’65 had several leftover ’64 parts installed, like this power steering pulley. Little things like this add to the charm of the car.