Yowza, you guys like the air filter how-to, so I thought I'd do one on painting an engine. There's always a thread on how to do it, what paint to use, etc. Here's how I am doing it, for a show car. You can take out the "anal" prepping of the parts, i.e., sanding, polishing, and just follow along to do any engine normally. but the time and tools I use to do this one (and it wasn't the MOST detailed one I've ever done) are not real excessive...perhaps 8-15 hours in all, and a die grinder, with some 2" sanding discs, a carbide bit or 2, and some sanding rolls is all you need. Besides a spray gun, and compressor to paint.....I always use good quality can paint, not spray bombs. You can even use a cheap touch up gun you can get for 25$, they work great on things like this. Good catalyzed paint is much more chemical resistant, as well as abrasion and chip resistant. Goes on smoother, harder, so it is even easier to clean and keep clean. Here's our donor, a 235 slated to go into the Kopper Kart. Just a normal rebuilt engine so far, until I degreased it with Brakekleen, scrubbing off all the oil, and most of the old paint. Then I start grinding off the castings with a die grinder and a 2" pad, with 50 grit discs. I went through about 2 dozen on this job.
Next, after doing all the mostly flat areas, and the outside of curved area, we need to get into the concave curved parts. Here I use a die grinder with a carbide bit. Fortunately, the one I chose had a ball end, which pretty much fit into almost ALL of the concave areas around the oil galley, motor mounts, between the spark plugs, etc. I did use a pointed end bit to get into the fine areas around the lettering on the block. On this job I left the lettering, while on others I remove them with a 4" grinder and a flap disc. The choice is us to you what level of "smoothness" you want to achieve! Now, the carbide leaves a rough cut surface, as the burr tends to "skitter" as it cuts. But as a roughing in tool, it can't be beat. To smooth out the carbide's rough cut, I switch to a cartridge roll. You can get these from any buffing supply, Eastwood, or industrial suppliers. The rolls are differetn sizes, and grit, but for this I used an 80 grit cylinder roll, and some 80 grit cones, to get in deeper places.
Once all the grinding, sanding and polishing is done, I clean the block again. Brakekleen, carb cleaner, lacquer thinner, Prepsol all work well, just do a thorough job of it! This engine still had a tiny amount of what I thought was rust deep in some of it's pores. So I also gave it a nice scrubbing with Picklex, my new favorite prep chemical. It removes rust in a minute or 2, and also cleans off any oils present. Unfortunately, for these pics, it also dulled out the nice shiny surface I had, and I didn't get a pic of it before the Picklex! Now,before I get to priming, a quick lesson on masking. Use good quality making tape. Clean the surfaces very thoroughly so the tape sticks. I use gaskets as a reference, and tape off the openings so I get paint about 1/8 to 1/4" under the edge of the gasket. That's so NO bare metal shows, and begins to rust later on. I am using House of Kolor KP primer on it. It's an epoxy paint that has excellant adhesion, fills well, and sands easily. It also seals well, but that's not necessary here. You can also use etching primer, or urethane based primers. I have used engine primer in spray cans, and even POR-15 if the block is a bit rusty and you can't prep it the way you'd like, for whatever reason ( like it's still in the car)
Now, I did get a bit fussy here, but bear with me. After letting the epoxy cure for a couple days, I prayed a light guide coat on the parts, and then sanded them with 180 grit, dry. Now on some even fancier jobs I might use finer paper, and even use a bit of bondo, or glaze to perfect any glitches in the parts. But on this one, I won't, it's a fifties custom clone, and I know they wouldn't have done half this detailing to the engine, but I do want it to look nice. And besides, Pearl paints really look terrible on rough surfaces, so I am getting it smooth enough where it won't look bad, but not overdoing it.
Next, I put one more coat of epoxy on it, to cover the bare spots from sanding, and also to help the paint to adhere. Even after sanding it, there were still some nooks and crannies where you can't get it as nice as you like to, so a little extra help is good. The primer will stick to itself better than paint would. It also evens up the color, again where there were sandthroughs. Let the primer set up for about a half hour, and then put the paint on. If you let it dry overnight, you would have to sand again, so I prefer to do it right away, and save another sanding step. In our case, House of Kolor white basecoat. Vic took the shot of me working on it. You really have to hit the engine from all angles to get even coverage.
Oh, yeah, the paint! I really recommend using good automotive spray paint on engines. The paint is a lot tougher than spray cans, which are usually "way too thinned out", cheaper quality, and tougher to control flow out and dry time, making it harder to get a nice paint film. Yes I know a few guys have really perfected using them, but in general, good paint out of a spray gun will always be better! I have used, successfully, in the part: Centari (acrylic enamel) with hardener, Imron (polyurethane), Single Stage Urethane, Base Clear (with good clear, of course), even House of Kolor urethane Kandies! Just stay away from lacquers, either primers, or paint. They don't stand up the the heat. By using regular automotive paints, you really have a great color selection. Match your car's paint color, or trim color, or interior, whatever! On this shoot, I am also putting white pearl over the white basecoat. Jon Kosmoski sent me some new pearls he is working with, that have more brilliance than the current ones. I really like the brightness, and purity of the white on this one, so we are using it on the truck. The engine compartmant was painted copper, and the engine white, originally. So we are painting it the same colors, if not the same paints. Here it is in white pearl.
Last, but not least, I put on a coat or 2 of clear. Don't add more paint than you need on the engine, as more will not make it better. More can lead to early failure on a driven car. In our case, it will be driven, but rarely, I suppose. I also did the oil pan, which needed a LOT of bodywork, as it was clearanced for a dropped tie rod, the timing chain cover, water pump, and bellhousing. The pulleys and brackets will be black, or chromed, Road draft, T-stat housing chrome, aluminum intake polished, exhaust manifold grey hi-temp powdercoated. The finned aluminum valve cover, and side covers will be polished, with copper painted between the fins. I don't have any other shots of it completed, as I just came from the shop after finishing the painting tonight! I can post pics later of it assembled and in the chassis, in a couple weeks.
Damn, the pearls really don't show well in the pics! Believe me, it looks better in person! Hey, Jim, I resemble that remark!
Thats not how you do it. Get Brite Beauty Engine Paint from Wal-Mart, much better haha. Thats next on my list for the '51, finished the mockup last wknd so now its time to spray the block and assemble. You didn't use their sealer? Just let the epoxy tack and base over that?
Billy I usually don't use the sealer, as the epoxy is a good enough sealer on it's own. I do use it in special circumstances, though, if the situation warrants it. I actually DID use the white sealer as the basecoat on this engine. I wanted to save a coat or 2 of film thickness, and I knew I could even out the color of the primered engine (dark spots still showing through the one coat of epoxy) and get my white base in only ONE coat. And if the color of the sealer is not exactly the same as their white basecoat, it doesn' matter anyway. I also use their metallic sealer as basecoat on some jobs, as well. It's good stuff, just like the rest of their products! Here's another engine I did with the same techniques, I just did it a lot smoother. It's my 292 in my 46 Chevy coupe.
Excellent job,Mark! Im gonna paint the Merc engine the same way. Hok primers& topcoats. The FE 390 i did with spraybomb engine enamel is got a couple a chips already.It aint like i dont have a compressor& sprayguns.I want to see that engine in person. Later Mike
Just to add to your excellent article, I find a Red scotchbrite is brilliant for getting primered corners smooth.
This is a great treatment of the prep and paint. Thanks for mentioning all the details. The finished product looks good, pearl show so well visually, in person, so the customer will be glad for the detailing too.
Mark (chopolds) painted the engine in my truck about a year ago using this same method. It still looks fresh despite some run time and the truck being stored outdoors. I doubt there's a better way to get the job done and seriously folks, there's not much cooler than a metalflaked engine. Ed
Great tech article and I knew about automotive finishes on engines but I never knew about using a 2K primer as a good base. I do have a couple of motors I need to do this with and I will definitely bookmark this article for future reference!!!
The Jalopy Journal
