When should I paint my engine?

[DoubleD]

I am building a new engine for my car, the block has been thermo cleaned and looks brand new. When I get the motor back from the machine shop, when should I paint it? Should I paint it before assembly? Should I wait and do it after the long block is assembled and paint the seal housings at that time too? Oil pan is powdercoated black, engine will also be black.

[moparmike70]

I would paint it right away before assembly because you'll be handling oily engine parts at that point. Right when you get it from the machine shop will be the cleanest it will ever be.

[iTurbo]

+1. ^ I paint the blocks after all machine work and cleaning as been done, but before any assembly. It's much easier to mask everything off and paint it like the factory that way. Otherwise taping/masking would be a nightmare, unless your just going to spray everything one color like an industrial engine.

There is a very good article by JT in the Knowledge Center on this topic.

[DoubleD]

+1. ^ I paint the blocks after all machine work and cleaning as been done, but before any assembly. It's much easier to mask everything off and paint it like the factory that way. Otherwise taping/masking would be a nightmare, unless your just going to spray everything one color like an industrial engine.

There is a very good article by JT in the Knowledge Center on this topic.

I couldn't find this article in the KC. Should I mask off the block where the front and rear main and intermediate housings seal to the block or should I just paint that area? It is a machined surface if I recall correctly.

[moparmike70]

Anywhere there is a gasket and any part considered the "inside" of the engine should be clean and free from any paint. All freeze plugs should be installed before any painting and they can be painted over. Rear of the engine can be painted except for the rear main seal area.

[83scamp]

Anywhere there is a gasket and any part considered the "inside" of the engine should be clean and free from any paint. All freeze plugs should be installed before any painting and they can be painted over. Rear of the engine can be painted except for the rear main seal area.

+1. General rule of thumb: If it's a machined surface, don't paint it...

[moparmike70]

Fyi, if you do by some chance get paint on any surface there shouldn't be just put some paint thinner on a rag and wipe it off just like that. Never use any abrasives. Keep the engine as clean as possible.

[iTurbo]

I couldn't find this article in the KC. Should I mask off the block where the front and rear main and intermediate housings seal to the block or should I just paint that area? It is a machined surface if I recall correctly.

I would only paint the sides of the block and leave the front/rear free of paint.

[BadAssPerformance]

There is a very good article by JT in the Knowledge Center on this topic.

Thanks, it is also here:
http://www.badassperformance.com/mtech/blockpaint.html

[Mr overkill]

Do what I did. Powder coat it

[DoubleD]

Thanks for all the responses, Now I am trying to decide if I should paint my engine block black or silver?

[83scamp]

Make it stand out. I did mine in Hemi orange...

[omniac]

silver will only show all the dirt - go factory black and then add color to your intake and valve cover

[DoubleD]

Intake, valve covers, valley cover, intercooler and intake piping are all wrinkle black. I was debating if that is too much black.

[omniac]

My 1989 Shelby Daytona is factory black, including wrinkle valve cover and intake. IMO, keeping it stock looking only increases value - painting it your favorite color adds a personal touch that others likely won't appreciate or will want to change anyways. However, if I had the ambition and time, I'd have my valve cover and intake power coated garnet red to match my interior and keep the rest black. I saw this color combo on a minivan and if i could post pics I'd show you. Perhaps check out the site for engine bay pics to get an idea what looks good

[iTurbo]

I prefer the standard semi-gloss black such as the NAPA engine enamel. I've painted 4-5 2.2/2.5 blocks and always used the NAPA engine enamel and primer and have been pretty happy with the results. They make a "Chrysler/GM" low gloss black (DE1634) that is probably closest to stock, and also a semi gloss black (DE1635) that looks really good too. I've also painted a 2.2 TII block "Chrysler Industrial Red" (DE1632) and that turned out great too. Kind of a fire engine red color. I've been kicking around the idea of painting my latest TIII block white (DE1602). But I will probably just go with the low gloss black. You can't see really any of the block underhood anyway and it might make finding oil leaks easier ha!

In all cases I used the NAPA engine enamel primer (DE1612) which I would highly recommend, even if there is still some factory paint left after all your efforts at
getting the block as clean as possible. If you do use the NAPA engine enamel, make sure not to hit any of it with Brakleen afterwards because that will strip the new paint right off if it hasn't fully cured, which probably won't happen until the engine heat cycles a few times.

I think Tyler (Turbo224) painted a TIII block with the cast iron (DE1651) and it looked great!

[Dr. Johny Dodge]

when you have a nice pretty , clean painted motor do yourself one big favour

DON"T leave it parked outside in the cold all winter without starting the car at least every week or so

why ?

because like an unheated house the paint will shrink smaller than the engine block from the cold
this will cause the paint to crack everywhere and start to peel up around all the cracks in the paint - just like the paint curls up and flakes off the unheated plaster wall

a few heat cycles will help prevent that from happening

when painting , primer is good
always try to keep the paint thin - you don't need solid colour in the first coat - or even the second one

also , I always liked to add the first coat (light) of colour ontop of still slightly tacky primer when painting an engine

you also don't need a heavy solid coat of primer , just enough to fog it nicely so it gives you a decient surface to paint on

thick paint = chips

[ajakeski]

Eastwood engine paint is the best product I have used.
You can buy it by the quart and spray it from a gun. The finish is outstanding and more durable than rattle can paints.

[DoubleD]

It's painted now, did it right after getting the block back from the machine shop.

[iTurbo]

Nice!