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5 Tips for Painting Your Project Engine
Depending on who you are and what you enjoy, a greasy, grimy, and nearly unrecognizable engine might be exactly what you want. You’re probably in the minority, though. For those of us who take the time to tear down an engine and refresh as much as we can mechanically, going the extra mile to dress up the parts and pieces before they go back together is worth the effort to in order to create a professional-looking final product.
The best part about painting an engine is that the process is not particularly difficult or demanding compared to painting an entire car. A few rattle cans can take any engine from a bland lump of metal to an eye-catching piece that shines both when you push the accelerator and when you pop the hood. Here are five tips to keep in mind when it comes time to doll up that chunk of iron or aluminum.
Remove Your Flash
If you want paint to stick and look good, removing the sharp edges and leftover material from the casting process is a must. I picked this tip up from Hagerty’s resident engine-rebuilding expert, Davin Reckow. Initially, I thought he removed the exterior casting flash simply because he had the tools out after doing the same to the interior of the block and heads to assist with oil drainback, but after seeing a few of his projects painted, it became clear the effort was well worth the work.
Make Sure All Your Work Is Actually Done
When you think it’s time to paint, take one more day to run through the checklist of work completed vs. work needed, before ordering your paint and busting out the masking tape. Once you start the masking process, it is a real pain to go backward and it often risks damaging your finish.
Clean Is Likely Not Clean Enough
Engine building is a clean-room affair, but painting is even more so. Old engines were typically caked and coated with grease and oil for decades, plus anything that applied to the raw parts after machining or other work. Use the paint process as the opportunity to go through and get everything for your engine flawlessly clean. Davin recommends that everything be “ready-to-assemble” clean before going into the paint booth. Taking the time to paint a part that still needs to be cleaned before assembly is asking to accidentally goof up that fresh paint. Even the masked-off areas should be spotless.
Use the Gaskets for Masking
When it’s finally time to lay down some tape, don’t think too hard as you are putting it on. Over-mask and then use the gaskets to trim the tape back to ensure the paint covers everything it needs to and nothing it doesn’t. This also helps keep paint from getting oil-soaked and creating leaks, since the gasket will seal between the unpainted surfaces, but the paint line will disappear between the parts when they join.
Use the Right Product in the Right Place
On the human scale, engines get very hot. On the larger scale, not so much. Although parts of an engine do reach temperatures that require special coatings that will not bake or flake off, the vast majority of components will not exceed the roughly 220-degree operating temperature of the engine. That means regular automotive paint will hold up just fine. Davin has the Redline Rebuild engines sprayed with a standard automotive primer/base/clear system, and the durability and oil resistance have been great. So long as the top coat is a catalyzed product, there have not been issues.
One thing I hate is when someone assembles everything – with gaskets – and then paints. It looks awful to me. Please, please, paint your individual parts and then assemble!
Depends. How was it originally painted from the factory and do you want it original looking. I know a guy who wanted his engine smooth so he ground the castings all smooth and applied body filler to places. THAT is crazy amount of work.
I did that to a Saginaw transmission case. I sanded for literally days to get that smooooth look. It looked good, but I will never do that again!
As for painting gaskets. Sometimes people have to as that is how it came from the factory. It was a common thing. Never looked good but they were just getting them out the door.
Painting the engine is not really hard. Just get it clean. The hard part is keeping paint on the heat cross overs.
The first thing at the Pontiac nationals many do is get the paint out and touch up the cross overs.
We used to race so we general had our blocked off and it would last. We also did not winter drive.
Today we have plastic intakes with no heat in them.
Having been in engine plants of the big three, many engines over the years were painted as a unit with valve covers and gaskets already assembled, as well as water pumps and some brackets, Also be sure to paint the correct color. Many “Cadillac Blue” paints don’t match the Dark blue that was used in the factory from 1949-1976. Always bugs me to see later lighter blues on one of these engines.
I agree with getting the correct color and shade. I don’t know how many 1966 and newer Ford engines people painted Ford Blue which was a medium shade and used prior to 1966 on many but not all Ford engines. I believe the Ford dark blue or also called Ford Corporate Blue was used exclusively from 1966 until they went to the grey in, I believe, 1980. Then of course there’s the GM engines that all went to the GM Blue after the scandal involving Chevrolet engines installed in Cadillacs.
In addition, thread old otherwise junk bolts into threaded holes so you don’t have to clean up the engine threads later on.
What engines came with clear coat on them?
Apparently Davin’s.
One other way to trim the masking tape is to tap the edges with a plastic hammer and it will peel off perfectly.
a tip I learned ages ago …. never paint your engine the same color as any fluid that will be inside it ….tracking oil leaks on a black engine …or coolant leaks on green or orange engines comes to mind
Are you redoing a car that’s been shown before? Tire dressing makes everything purdy but it’s full of silicone and paint will NOT stick to it. In fact it will run away from it causing fisheye everywhere. If the engine was ever detailed it takes a LOT of work to get rid of any silicone seeped into the engine and components.
Right on! This is also the bane of furniture refinishing shops. If people used silicone cleaning solutions or polishes, it’s tough the get a new finish to stick.
Cook the block! This will help to release oils from the block’s pores! Can be as simple (read back yard) as going over the whole block with a propane torch until the smoke stops. This is the biggest bang for the buck on getting new paint to last for many years without peeling! Thank me later 🙂
I’ll add that I’ve been applying a zinc-rich primer to engines before painting, and decades later they still look good – no peeling or flaking. The factories didn’t do that, so it may not be strictly “correct”, but the paint covers the primer (and it requires less paint to do so).
Threading sacrificial fasteners into holes you don’t want to clean up later is also a good idea.
Painting an engine is one thing I would never attempt. I don;t have the equipment or time to do this. Admittedly most modern engines don’t go for bright paint colors these days.
Unless you are going for a “Riddler” award paint the engine the appropriate color and shade for the car’s year and model it is going into, even if it’s modified there is nothing worse than seeing a nicely done Pontiac GTO for example with a correct Pontiac Engine that is wearing Chevy Orange Paint, Why would you do that?
Paint with a base coat and clear? Well, OK if you are going for a Riddler, but really…
I use a good rattle can paint for engines, and paint before I assemble, when it is fresh out of the hot bath from the machinist. No painted gaskets, no painted over fasteners (especially when I like to use fresh plated or stainless hardware.
Even better, my current rebuild is an all alloy engine, so no paint at all.
Sometimes I match factory color, sometimes whatever I have on the shelf (usually red, BMC green or black). Depends on the sort of build that the entire car has been through.
Agree 100% on rattle can engine paint. The stuff is high quality and lasts. Many factory colors are available.
I’m a firm believer in Krylon.
I left detailed instructions with my extremely experienced “show car painter”, regarding how I wanted him to paint my factory 327 engine, which I had removed from my 1963 Corvette. Obviously I wanted Chevy Orange (regular gloss) on the block, including intake, valve covers (300 hp) etc, but also on the gaskets, water pump, exhaust manifolds and locks, including partial spark plugs porcelain. Do this all with attention to a nice glossy upper engine application with less care lower down by the lower oil pan. A slight paint run or two on the oil pan corners would be fine.
A week later my painter called saying my engine was done. He asked if I could please pick up the engine as soon as possible…..and it is in the back of his shop. It is not being displayed in his lobby (with several other engines he had finished). Upon my arrival, he jokingly said “don’t tell anyone I painted this!”
Yes we are good friends….just different appreciations of the same hobby.
That same year my ‘63 obtained a Bloomington Gold, NCRS Top Flight and Duntov. I doubt I will do another engine that way.
who remembers the House of Powder in Standard Illinois? when building my 34 Olds I took everything over to those guys, they did the engine from intake manifold to the oil pan including the block, heads, that was around nineteen ninety, my car has over ten thousand miles on it and the powder coating still looks great, they also used a high temp coating on my headers and turbo, they used to powder coat the frames and suspensions for the giveaway street rod at the NSRA nationals.