"Is it Safe to paint Aluminum Heads????????"

I'm currently working on a project that has aluminum heads and they really look out of place and I was wondering if it is safe to paint them?

My concerns primarily are... will this adversly effect the "Heat Dissapation"of the heads???

If not... What type of "prep work" is needed before primeing??

I have them on the engine allready so bead blasting is out of the question... would a self etching primer work just as well??

What brand would you recommend?

And what type of primers to use to maintain the coatings durability in high temp extremes?

Any ideas...???

 

Go ahead and paint them.
They only get real hot around the exhaust port flanges.

 

Agreed. Just use a good etching primer to keep the paint from flaking off after time. Zinc chromate primer works real good too.

For an example, Harley Davidsons and many others paint the aluminum engines in the bikes and they get much hotter than a liquid cooled engine.

 

Go ahead. The heads on my friends 10 second Plymouth are painted with no problems to date.

 

Alumi-prep (cleaner), followed by Alodine (conversion coating); used on aircraft skins before painting. These are available in auto paint stores.

 

Yes.

No, the heads do not dissipate large amounts of heat. Cast iron is poor at heat transfer, aluminum is way better, as such, you are way ahead of the game with aluminum heads anyway.

Get it clean and slightly "scuffed". Bead blasted or something else, anything but polished.

Motors don't get hot enough to comprimise paint in most cases, unless they are an early caddy or the like with exposed lengths of exhaust port. Intake manifold heat risers also have the same effect, but there aren't many paints out there that will take that kind of heat anyway.

Hose it down with your favorite crayola color and it'll be fine. David

 

Sure you can paint aluminum heads. If you like you can even make them look like a different version of the head........

Here the head is after I ground the machined flat serface to look like an early small block head.


Then I painted it to the color used in this vintage engine


I also needed to relocate the rocker cover bolt holes to the early non-inline layout


Looks like a new 1957 chevy engine ready to install.

 

Dinoroom , do you mind if i borrow that for 20 years or so?

 

Dinoroom, that is the best looking smallblock with aluminum heads i have ever layed eyes on. Nice job.

 

Love the 9 fin valve covers.

 

Very nice .

 

1952henry has it pegged. Follow his steps an you don't have to use primmer. Frank

 

dinoroom, looks great, but your not gonna fool anyone with those side mounts still on there! did you have to add material to tap the staggered hole in those heads??

 

Dupli color engine paint works fine without a primer coat.
I have a set of Aluminum Pontiacs and a set of Indy's installed and painted for a while now-no issues.

 

Dynoroom, I have so kicked this idea around for a "327" build for
my 57 delivery,yours is the first faux powerpack i've seen. Great job!
I'm sure 99.9% will never know the difference. I've figured that after approximating the fuelie head end that I'd just put a wet coat of paint on and sprinkle some garden variety sand on it and then recoat
the color.

 

revkev, yes we had to weld a tad for the staggered rocker cover bolts but it was no big deal.
What side mounts? Did I miss something? The customer was pleased, he wanted it to look original and make 400 hp. The block was an early 283 that I put a 3.25 stroke in to make it a 317 ci. Note that we retained the road draft tube. We also made the power he wanted.

 

Here's a picture of the engine on our dyno. As you can see there are no side motor mounts.



And to everyone else thanks for the kind words.

 

I have one of those 57 motors in my coupe. Except my are power pack heads not aluminum. But I will trade ya any day.

 

Well that just kicks ***.

For anyone wondering, the 9-fin covers were '56 only. In '57, the top fin interfered with the side air cleaner on the fuel injection units. The first units down the ***embly line had the top fin clearanced by hand with a grinder. They re-tooled the molds, and were 7 fins from then on.
Thinking about it, I'm sure they must have known about the clearance issue well before the first one went down the line--they probably just used the left-over stock until all the 9-fin covers were gone.

Great looking engine, and I really like what you did with the ends of the heads. What heads did you start with?

-Brad

 

Dynoroom thats nasty....thats my plan for my SBS...a 383 that looks totally trad with aluminium heads. BTW, what heads did you use and what are your combo's spex?

Just super sano...very nice.

Any dyno figures?

Rat

 

Nor with the absence of mounting holes on the heads (!), but who cares?! I've got a set of Edelbrocks atop an old motor I'm gonna backdate as such, and was curious about the "finish" on the heads. Is it just machined, or do some mfg's actually put a coating over the aluminum to give it that sheen?

 

RF, do you mean front accessory mounting holes on the heads? Early heads don't have front mounting holes. My 462 castings sure don't.

 

Dynoroom, where did you get those spark plug heat shields?

 

Dynoroom, did those heads have the higher ridge for the valve covers??? what did you do there????
ive been planning on making my rhs heads look like doublehumps...
im gonna make mine look cast by laying 30 grit sand paper on the heads and tapping it with a br*** hammer.......

 

If I remember the plug wire heat sheilds came from Chevrolet, I don't think Danchuk has them.

quote s****e "Dynoroom, did those heads have the higher ridge for the valve covers??? what did you do there????"

The heads we used were Edelbrock's. We didn't do anything special except weld a pad to move the rocker cover bolt hole over & grind the flat machined end of the head to make it look like a power pak heads.

Someone asked about the horse power. The engine is a stroked 283 using a 327 crank making it a 317 cubic inch engine. The customer wanted 400 hp we gave him 410 @ 6500 rpm. The limiting factor being the carter carbs & intake manifold or it woulda made 475! It's in a nice '57 chevy and hits the cruse & car shows of SoCal.

Thanks again for all the kind words on our project.

 

Use a good zinc cromate primer if you can find one. It will help with the adhesion to the aluminum. At least use a good self etch. Otherwise there are products to prep aluminum and leave you with a zinc phosphate coating ready for primer.

 

Dang that's a nice job, Dynoroom.

Do you think Chevy would still stock those heat shields or are those sort of NOS parts?

 

show up at your local dirt track and ask some of the bomber (street stock) guys if you can paint aluminum heads.... i'm sure someone can even tell ya how to p*** tech in a cast iron head cl***.... brandon

 

One of the funniest things about this is that all other things being equal (porting, valves, springs, etc.) the cast iron head WILL make more power.

 

So why would you spend the money on some alloy heads to be equal? The point is they're better because the have a larger port cross sectional area, bigger springs, & I can run more compression on the available fuel.