Buying guide for the best engine enamel paints
Maybe your engine is looking a bit old and tired. Maybe you’re building a hot rod and the motor needs to look its best because it’s going to be on show. In either case, a good engine enamel paint — properly applied — can make the block look like it just rolled off the production line.
There are plenty of products to choose from, but you need to be careful. Engine enamel paint not only needs to withstand high temperatures, it also has to cope with rapid fluctuations — from freezing to several hundred degrees in a matter of minutes. It has to resist oil, gas, solvents, salt, and road contaminants. Good engine enamel paint is really tough stuff.
We have researched the market so we can help you choose the right product for your vehicle. We also have a few recommendations in addition to our top picks. In this buying guide, we look at the best engine enamel paints in more detail and answer the most common questions.
Why engine enamel paint?
The outer surface of your engine when running is typically somewhere around 250°F to 300°F. Normal metal paints just can’t cope. Engine enamel paints can handle temperatures as high as 500°F, depending on the formula. Some also have ceramics added that help to dissipate heat more quickly, prolonging the life of the paint. This has no impact on engine performance because it only affects external temperature.
Once fully dry, engine enamel paint also provides a very hard surface that is resistant to chipping, corrosion, and chemicals. Engine enamel paint is also very versatile in its appearance not only in its available colors but also in its finishes. It may be high gloss, matte, or even textured, and it will retain its appearance for years with minimal care.
Key considerations
Chemical composition is increasingly important in terms of the environmental impact of engine enamel paint. Engine enamel paints have historically been oil-based with all manner of unpleasant compounds included — some of which are now banned. Low solvent/low VOC (volatile organic compounds) products are a big improvement, with acrylic (water-based) engine enamel paints being the optimum choice. Fortunately, an increasing number of manufacturers are providing acrylic options. However, the formula is not always clear from the product description, so you may have to check with the manufacturer.
Engine enamel paints are supplied in spray cans or as brush-on liquids. Spray cans are quick and easy to use. Just shake (usually for a full minute) and go. Some feature nozzles that can spray sideways or upside down, which is far more convenient than the type that need to be kept upright. Brush-on engine enamels take longer to apply and more care is required, but in general they offer much better coverage. A little goes a long way, thus saving you money (manufacturers often provide specific figures if you want to check before buying.
Painting and drying times need to be adhered to in order for the layers to bond to each other properly and for final curing to maximize surface durability. Sometimes subsequent coats need to be applied quite quickly — typically within 30 minutes. If this can’t be done, then you may need to wait a full day before re-applying. Some products will be fully dry overnight, while others require as much as a week. There’s no hard-and-fast rule here — you will need to check the instructions provided by each manufacturer. Professional auto sprayers can speed up the process with the use of a drying booth, but most of us just have to be patient.
Color matching is important to some, and manufacturers often make statements like “OEM match,” or “factory original color.” Whether those are accurate is open to debate. You can check with owners clubs and online forums (particularly vehicle restoration forums) to find user feedback. However, you also need to realize that the color of your motor has probably changed since it left the factory. It’s been through thousands of miles of road use, probably in all weather. The color it is now is not the original, so getting a match is impractical. Ideally, the new color should look better.
Engine enamel paint prices
Inexpensive: If color isn’t important, it certainly pays to shop around. We found glossy black paints in 12-ounce spray cans for under $5.
Mid-range: Twelve-ounce cans are far and away the most popular size, and you will normally pay somewhere between $7.50 and $14. Color can make a difference — even from the same brand — and paints that claim to be an exact match to factory originals are at the upper end of this bracket.
Expensive: Some specific motorcycle engine paint costs a little more (though still less than $20 per 12-ounce can) and some colors can be close to $25. This is most likely due to paints that are more complex to formulate than others. Liquid paint is a little more expensive, with 16-ounce tins available between $25 and $30, but coverage is much better.
Tips
Engine enamel is straightforward to apply, but proper preparation and application may have a big impact on finished job. It should go without saying that you need to follow the manufacturer’s instructions, but the following tips provide a good starting point:
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Your engine should be completely cool before you start.
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A full engine strip and removal is recommended. Otherwise, remove as many components from the engine as you feel comfortable doing.
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Anything left on the engine needs to be wrapped in plastic and secured with tape. Great care is needed if you’ve left electronics attached.
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Clean the engine thoroughly using a degreaser — water-based versions are the most environmentally friendly. Remove flaking paint with a fine wire brush. Rinse thoroughly with water.
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When dry, lightly sand painted areas using 320- or 600-grit sandpaper to remove the existing surface and provide a key for the new paint. Rinse again to remove dust.
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Allow the engine block to dry, then mask any areas you want to keep paint-free.
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Apply spray or paint as instructed. Don’t rush. Multiple thin coats are better than trying to get it done in one hit.
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Leave the engine to dry as indicated by the manufacturer. If the motor is still in place, don’t be tempted to reassemble and start the car to speed up the process, you’ll likely blister the paint.
FAQ
Q. Do I need to remove the vehicle engine before I paint it?
A. No, but it will make painting easier and will reduce the chances of you contaminating sensitive electronics. If you leave it in the engine bay, then no matter how much you strip it down there will be areas that are difficult to clean and spray properly. It really depends if you’re painting your engine for general appearance, or for show purposes. If it’s the latter, you really need to take the engine out to paint the engine properly.
Q. Do I need to use a primer before applying engine enamel paint?
A. It depends on the product. Some recommend a primer, some say they can be used without. We can’t over-stress how important it is to read and follow instructions carefully.
Q. Can I use engine enamel paint on my valve covers and engine bay as well?
A. Yes. As with your engine, follow the instructions for preparation before you paint. There are a few products for valve covers that reproduce the appearance of aluminum, cast iron, or you can go for a color to either match or contrast with your motor.
