Valvoline.com

Engine Compartment Detailing

Tricks for creating a show-quality compartment

Many times during an engine rebuild the attention is only on the motor and not on where it lives. While the powerplant is on the engine stand, you have a golden opportunity to renovate areas you normally don't have access to. Once that chunk of metal is reinstalled, the detailing process is much harder. Here are a few tips on areas to address and how to breathe new life into old parts that make up your GM engine bay.

Booster

First, you must remove everything that can be unbolted in order to completely clean the compartment. Four 9/16-inch nuts secure this power brake booster to the firewall and a clevis pin on the actuation shaft under the dash must also be disconnected. With this large part removed you can detail, sand and paint the parts and areas around it. Installing a freshly plated booster is a must for a show-quality resto. Most restoration brake suppliers have these boosters and the correct master for your application. Be careful not to drip brake fluid from the master cylinder onto your painted parts—it works better than paint stripper.

A-Arm/Removal

Here is the passenger side A-arm and crossmember after the engine was removed. The old rotted A-arm cover was also removed and new replacements are available. This compartment went through several cleanups with the engine in place, but never when everything could be easily accessed. Use a liquid cleaner that cuts grease and a green scotch pad to remove the dirt and then wash the area with water. If you need to sand out deep dings in the paint, be sure to use 100-grit paper followed by 400-grit paper, then apply primer to the bare spots.

A-Arm/Resto

Here is the restored A-arm on the passenger side. What a difference a little handwork can make. The shock washer and nuts, alignment shims, large nuts securing the A-arm and the bushing washers and nuts were removed and wire-wheeled. After a thorough cleaning, a coat of aerosol clear enamel was applied. This will make hose-off cleaning in the future much easier and prevent rust. A green scotch pad was also used on the crossmember and then the areas were painted semi-gloss black like the original.

A-Arm/Install

The A-arm covers were attached at the factory with staples installed with a large gun. Aftermarket resto suppliers have the covers and staples, but now you have to install them by hand. One person can do the job, but a helper makes it much quicker and a lot easier. Careful measuring and ample patience will pull it off. Use a small drill bit to drill the holes in the cover and then install the staples one at a time, starting in the middle top and working out and down on each side. Your helper can bend the staples under the wheel well.

Sanding

If the metal surfaces of your engine compartment are not badly dinged up, a green scotch pad will rough the surface enough to apply new paint. Make sure there is no shine left after you finish the sanding and thoroughly wipe the surface with a damp towel before painting. This process can be used throughout the compartment on most surfaces. The scotch pad is more pliable than normal sandpaper, allowing you to easily scuff areas that are hard to reach with the stiff paper. These pads are available in most markets and come in different colors depending on the roughness. Green is a medium-grit pad.

Washer

Parts like this body grommet-retaining washer can be removed, cleaned and reinstalled without any body parts shifting. The bolt, nut and washer were wire-wheeled to bare metal. Then the bolt and nut were cleared and the washer sprayed with aftermarket cadmium-colored paint. Small bright parts like this really sparkle up the engine compartment and are easy to restore with the radiator and shroud removed. New copper ground straps are another nice touch and are available from most resto retailers.

Steering

The aluminum cap on the steering box can be masked off while painting the box itself and then cleaned with lacquer thinner on a rag. Once all of the dirt is removed, use a fine wire brush to brighten the surface of the aluminum. Be sure to clean out any accumulated dirt in the depression in top of the adjustment nut. The bolts can be removed one at a time and wire wheeled. After the area is totally cleaned, a coat of clear can be applied to the cover and bolt heads. Notice the date of manufacture stamped into the cover. Previously it was buried under old paint, grease and grime.

Brakes/Block

The brake-fluid distribution block is copper and normally painted over or covered in dirt. It can be removed from the frame rail and cleaned using a fine wire wheel or brush (another nice bright touch to an area normally hard to get at with the engine installed). While you're at it, be sure to clean the threads for the brake lines. If the block is heavily covered in paint try using lacquer thinner to cut the surface debris away before attempting to polish the surface. Yes, a coat of clear was applied to keep the shine on this small item.

Brakes/Lines

New brake lines are a must for a complete engine compartment redecoration. Pre-bent steel or stainless steel lines are available to replace the originals. The line retaining clips were removed and cleaned while the front line was removed. Many times the original lines get crimped or rusted over the years and replacing them is always a good idea. The end fittings are 3/8-inch. Always use a line wrench to remove and replace these items. Once you round off the fitting using a normal wrench there is no good solution but to purchase another line or bend your own.

Wiper Motor

The windshield wiper/washer motor should be removed from the firewall, cleaned and repainted. Most were gloss black as shown here. Again, use a green scotch pad to scuff the entire surface and mask off the plug-in connectors prior to painting. The only gloss items on the early GM firewall are the Delco-Remy voltage regulator cover and the wiper motor. We used an aerosol gloss enamel from the auto parts store. The voltage regulator cover is easily remove and repainted as well.

Wiring Harness

Replacing a 30-plus-year-old wiring harness is always a good idea. Most restoration suppliers carry harnesses for whatever application you need. There are normally two in the engine compartment—one for the front lights and horns and one for the engine electrical. You must specify if you have A/C and/or an automatic transmission. Here you can see the detailing of firewall parts, steering shaft, voltage regulator, ground straps and the new engine wiring harness. Having the correct connectors already installed on the wires is a definite advantage for a restoration. The alternative is butt connectors on every wire, which is totally incorrect.