Properly painting the short block

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Mean416

Mean416

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Guys I'm curious the approach you have used with success. I'd like a durable paint finish for the short block that withstands chipping and peeling. The problem areas in my experience have been next to the timing cover, and around the distributor. It always seems like these areas just chip and flake, expecially when pulling some of these parts. Like if you pull the timing cover and gasket it seems to just tear the paint right off. And that's a proper pain in the butt cleaning up and repainting. Especially if you have a raw aluminum finish on the timing cover.

I've used por15 engine paint in the past and had these results. Super clean prep work, laquer thinner cleaning, spraying the por15 on etc. I understand the basic fundamentals of painting here. Looking for suggestions with experience to back up.
 
I assume your playing with cam timing if you need to pull the timing cover? I think you've got the painting part down, you just need to get the engine/timing right and let it be. If it's going to be a "test bed" engine, then it is what it is.
 
Don’t paint where the gaskets sit. Then when you pull the gaskets it won’t pick up the paint. I usually use the gaskets as a template to tape off a short block for paint.
 
Use catalyzed automotive paint and this will not happen. This is the way to get a durable paint finish that wont discolor or peel off.

you need to have it very clean and dry.
 
All aluminum parts should have a light coat of self etch primer. The iron block scuff all machined surfaces to be painted with a coarse scuff pad. Wash all iron surfaces with thinner but avoid self etched primed parts. Then prime the whole thing with engine primer right over the self etch primed parts. Then Paint it what ever color you want withing 1/2 hr.
 
Long blocks were painted after engine assembly.

They did not paint short blocks.
 
413 said:
Use catalyzed automotive paint and this will not happen. This is the way to get a durable paint finish that wont discolor or peel off.

you need to have it very clean and dry.
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Any specific recommendation?
 
I use regular old engine primer and then engine paint. Sometimes I just use the color and skip the primer like the factory did.
Clean clean clean... that's all I can recommend for keeping the paint on.
Maybe torch it to cure it faster.
 
After painting I shoot it with a coat or two of automotive clear. Nice shine and seals up the nooks and crannies. And I agree- all aluminum parts need self etching primer to make it stick. Light coat not super thick.
 
I always get a peel around the spark plugs. Id like to paint one with a brush once, nice thick coat Caterpillar style, bolts and all.
RP900898.jpg
 
Liquid masking works great on anything you dont want paint to stick to. Clean the metal, then brush it on with a brush. I use 2 coats. After an hour, you can use a razor blade to trim the mask away from the areas you want to paint. After painting, the liquid mask will peel away like rubber cement. This works great for small/detailed areas. JMHO.
 
Machinist hate epoxy paint. When cleaning and prepping a block for machine work it gets in everything . My son has me strip them and its not easy. Also ruins the glass beads It creates a dull finish if using afterwards . Several coats of paint stripper and wire wheel helps but it still sucks get off.

Light coats of engine enamel is the best. I guess if your motor is exposed like in a street rod it needs to shine. otherwise just a coating to prevent rust is fine. I don't know anyone that waxes their engine. And as far as clear it turns yellow . I did my intake and it turned ugly yellow. Now I just spray cast aluminum parts engine color or cast aluminum color. Maybe I didn't use the correct clear?

Here is a comparison of the intake and heads after time with clear on it. You can see the intake turning yellow. and it got worse before we pulled it. last picture is a good example. And the car was only driven to race or to shows.

Also I would never paint another engine black again.

spoiler pics 662.jpg


Steve 065.JPG


1DSCN2806.JPG
 
personally i couldn't care less what the machinist thinks of the paint....

epoxy prime, high solids urethane paint.. its pretty much bullet proof...

engine was painted in 2016. if i pop the hood and actually wipe it down a bit it still looks that good today..:)

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When Dad n I did the 273, we brushed on Eastwoods. Worked very well, set up QUICK. That was almost 10 years ago now. Held up good, but not a show piece by any means.
 
70dart340 said:
Liquid masking works great on anything you dont want paint to stick to. Clean the metal, then brush it on with a brush. I use 2 coats. After an hour, you can use a razor blade to trim the mask away from the areas you want to paint. After painting, the liquid mask will peel away like rubber cement. This works great for small/detailed areas. JMHO.
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Never heard of this can you provide a link?
 
abodyjoe said:
personally i couldn't care less what the machinist thinks of the paint....

epoxy prime, high solids urethane paint.. its pretty much bullet proof...

engine was painted in 2016. if i pop the hood and actually wipe it down a bit it still looks that good today..:)

View attachment 1715864567

View attachment 1715864568

View attachment 1715864569
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Agreed. I'm sure the epoxy is a b**** to get off but honesty that's kind of the exact point!

And I get it, some people are ok with things looking like butt after a couple months. That ain't me.

Your engine looks awesome!
 
What about these three? I'm not really an automotive paint expert by any stretch. Can I use the epoxy primer with the urethane topcoat? I'm thinking about gray for the block. I had black but it was a mistake to be honest. Makes it really tough to find oil leaks etc.
Screenshot_20220205-105219~2.png
 
Mean416 said:
Guys I'm curious the approach you have used with success. I'd like a durable paint finish for the short block that withstands chipping and peeling. The problem areas in my experience have been next to the timing cover, and around the distributor. It always seems like these areas just chip and flake, expecially when pulling some of these parts. Like if you pull the timing cover and gasket it seems to just tear the paint right off. And that's a proper pain in the butt cleaning up and repainting. Especially if you have a raw aluminum finish on the timing cover.

I've used por15 engine paint in the past and had these results. Super clean prep work, laquer thinner cleaning, spraying the por15 on etc. I understand the basic fundamentals of painting here. Looking for suggestions with experience to back up.
Click to expand...
I just painted my engine for the second time. The first time I primed and painted it with Duplicolor followed all the instructions - junk.
This time I took a differant route and used Van Sickle sprayed out Agricultural implement enamel in Gloss black using thier hardner and prepping it with acetone, and it turned out great. I contacted Van Scikle and they said that the heat from the engine would be no issue, just not recommended for exhaust manifolds. I can post some pic's if reqested
 
Mean416 said:
What about these three? I'm not really an automotive paint expert by any stretch. Can I use the epoxy primer with the urethane topcoat? I'm thinking about gray for the block. I had black but it was a mistake to be honest. Makes it really tough to find oil leaks etc. View attachment 1715864600
Click to expand...
Anyone know if this would work?
 
The Mopar paint works but you need 2X what you think you need. Its coverage is terrible but it looks nice when its done twice.
 
Mean416 said:
Never heard of this can you provide a link?
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Sure. I'll swim to the garage tomorrow and take a picture. Modeler's and R/C guys use it for their small RC car parts when they paint them. I'll look for a link to Amazon. It's great for painting small parts, like center caps, switches, turn signal housings, and on and on.
 
I mask off gasket surfaces with blue painter's tape. 3M seems to be one of the better tapes. The trick i use it to trim the tape using a medium to fine rat tail file that is gently run with a downward stroke along the edges. It pushes the tape down at the edge and cleanly cuts it. I have also used the knurled handle of a cheap ratchet wrench with similar results.

Prep for me involves cleaning the block using the water rinse-able purple cleaner, a good medium stiff brush and medium course scuffing pads. I follow that up on the dry parts with a lint free cloth and lacquer thinner or brake cleaner (sometimes with a tooth brush like scrub brush and wipe with a cloth). All surfaces need to be oil free.

I then spray the parts with VHT engine enamel using multiple medium tack coats followed with 1 or 2 full wet coats. I do let the paint dry for 15 to 20 minutes between coats, longer if it is colder out. There are minimum temperature requirements listed on the can. It is nothing short of amazing in appearance and longevity, and I have yet to have any adhesion issues with aluminum parts.

I always paint aluminum heads too, but I understand those who like to see them clear coated or raw.
 
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