by David Grainger
President, The Guild of Automotive Restorers
Few of us can resist the urge to open the hoods of our classic cars and show off the engines, whether we understand what is under there or not.
This fascination with what is under the hood is something that most women don't really understand as long as it works, but all of those wires and pulleys and bits and pieces appeals to our tinkerism which is a basic male instinct.
So what happens is as soon as you open your hood you are opening yourself to criticism, whether real or perceived and yet another automotive Pandora's Box creaks open with the groan of rusty hood springs.
Engine detailing is an expensive process which should usually begin with the rebuilding of almost all of the engine bays components including the engine itself. You can detail the engine compartment without rebuilding your motor but if anything goes wrong, you can wreck thousands of dollars of detailing when everything gets pulled apart again.
If you plan on detailing your engine, make sure that the parts that you are detailing won't need rebuilding in six months.
So what kind of detailing do you want? Many of us are just fine with a nice clean engine compartment but how do you go about cleaning off the accumulations of years of leaked oil, road tar, sand and mud? A lot of it will actually have to be physically scraped off. No matter how good the engine degreaser that you employ, none of them will eat through three inches of dirt and oil accumulation, and that is a common find on your front end components and in the areas around the bottom of the motor. If you are removing your motor to detail it this is all pretty easy, but it is far more difficult and patience taking if you are working with everything in place. Be prepared to jack the car up and put it on stands so that you can get at the lower areas which can be seen from the top, but not reached. A varied assortment of putty knifes and scrapers with different widths of blade will come in handy as will steel brushes with good stiff bristles.
Be prepared to jack up the car to get at those hard-to-reach places.
Once you have gotten off the heavy accumulations, you can start to use engine degreasers. Degreasers are available at most hardware stores and automotive suppliers. To get the best results it is a good idea to follow the instructions as different solutions require different applications to work properly. It is also a good idea to find out about disposal of the dirty water. You don't want to degrease your motor and find that you now have a toxic waste site in the middle of your lawn which won't allow grass to grow for the next hundred years. Some are environmentally friendly, some are not.
If you are not worried about the paint in your engine compartment Easy Off is actually one of the best and cheapest degreasers going, but it will also remove most paints or at least damage them so take that into consideration if you opt for using it. Paint damage may also result from the use of some other industrial grade degreasers so, once again, check out the instructions.
Common sense is the rule of the day anytime you are mixing water with engine components. You should rinse your motor with hot water and then either as much pressure as you can get from the garden hose or ideally a small pressure washer, but you must make sure not to force water into the engine through its carburetor or any of the vents or breathers.
A rag thrown over the top of the carb won't do it. Use duct tape and plastic to seal up your carb, oil dip stick tube and whatever vents and breathers that you have. Although it will be a good idea to remove valve covers and other things during the detailing, leave everything on during the initial degreasing. Later, when you are cleaning by hand you can remove valve covers and caps.
I have seen some mechanics degreasing a motor while it is running. Personally, I don't think this is such a good idea because on the chance that water goes into the carb you can get a hydraulic lock in the combustion chambers which can break pistons or bend rods. This is because water can't be compressed which is exactly what a piston is designed to do. In a fight between the two, the piston always loses.
You can run the motor before rinsing which will warm it up and help remove grease, but don't run it during.
Once you have degreased the motor, you will no doubt have to attend to some stubborn deposits in nooks and crannies and to do this use scrapers and even flat blade screwdrivers. Rags soaked in degreaser and a spritzer bottle with the same in it will also aid in getting out some of those stubborn deposits. After hand removal you may find it prudent to degrease the whole motor again to get it ready for the next step.
After all the grease and muck is removed you will usually find that, although degreased, the motor and bay still looks pretty shabby. Old paint will be largely gone and there will likely be lots of surface rust. This can be remedied with the judicious use of spray bombs if you just want to make things presentable. You should use only top quality paint such as Plasti-coat which is available in various factory engine colours. There are also other good quality engine paints available from suppliers including colours mixed for antique and classic Fords, Chevys, Packards, Studebakers and many more.
When using a spray bomb in your engine bay, removing things like ignition wires and other easily removed items is usually a good idea. If you are careful you shouldn't have to tape or mask up things that you don't want to paint but a rectangular piece of cardboard in one hand masking while you spray with the other is a good idea.
Don't use engine paint on your exhaust manifolds. Engine paint is formulated to withstand higher temperatures than standard paints but they won't survive a manifold. Here you can use specially formulated manifold and header paints. My favorite is cast iron gray which exactly matched the colour of fresh clean cast. The advantage of cast paint is unlike raw cast which rusts very quickly just with atmospheric moisture, the paint if it is properly applied, will last a long time and retain a fresh appearance under the hood. There is nothing worse than spending hours cleaning and detailing an engine only to have the manifolds and other raw cast parts turn bright red, seemingly over night.
An engine compartment can end up looking really good when done this way if enough patience and care is taken. It won't last as long as a fully detailed compartment which has been brought back to factory spec or beyond, but it can certainly be almost as satisfying when you lift your hood.