Engine painting

yzer

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I'm thinking about painting the engine.

It's a 1947 Chrysler Crown M7. I put off repainting it thinking I'd have to overhaul it for a rebuild sometime and I'd get it painted then, but the engine has been running perfectly well for the thirteen years I've had it. It runs much better now than when I bought it. There are no signs that it needs a rebuild anytime soon.

The engine needs new paint. It was repainted about twenty years ago in Chrysler blue (not correct color).

I refinished just about all of the wood on this boat and I'm good at it, but painting engines is new to me. I'm a brush guy. I'm thinking that one of those portable sprayers that uses pressure cartridges may be just the thing for this job, with small brush work in hard to reach areas. Some of the bolt-ons are painted black and I already painted those after I rebuilt them.

The block, head, exhaust manifold, and transmission are cast iron.

Any advice in these areas would be greatly appreciated.

1. Rust removal

2. Primer

3. Engine paint

4. Specific paint sprayer recommendations

Here is a photo of a Chrysler Crown Engine of the same series and vintage as the similar M7 with the correct colors. I'm guessing that this is an M-47. The bright brass/bronze is probably an example of creative “over-restoration", but it sure looks good.

marine13-1.jpg
 
Do you want it to be in restored condition or just repaint with correct color?

Can you get the correct color in spray cans or not?

Best bet would be to take it out and repaint to get it right. In the boat spray jobs most always have overspray, tough to paint the oil pan, etc. You will no doubt miss spots if it's left in the boat and you will make a mess of the bilge with the wire wheel and wire brush getting the rust and loose paint off.

Do you have pics of your motor in the boat?

That motor above looks great.
 
a great cleaning with simple green then rust converter where necessary then rustolium primer and color coats will work well if you aren’t removing the engine for a sandblasting
 
I'll show before and after photos when I do the job. It's too ugly for pix now.

I'm quite happy to disassemble engine parts as far as possible to get a good paint job, but I know that all engines of this vintage were painted after assembly and before the bolt-ons were attached.

I will have to mix the paint for correct color. I should be able to find the color formula, but the green shade is not commercially available pre-mixed.

High temp engine paint or not? I don't know. No part of this engine gets so hot you can't touch and hold it, including the exhaust manifold. I've never seen engine temps above 145.

I'm good at masking tape and plastic drop cloth. Worst case: I can recoat overspray by repainting the engine compartment.
 
a very hard dry roller would probably add that red color to the raised letters for extra zing.
 
Yes, that would be cool. The raised lettering should be easy.
 
quote:

Originally posted by Robyns Nest

Do you want it to be in restored condition or just repaint with correct color?

Can you get the correct color in spray cans or not?

Best bet would be to take it out and repaint to get it right. In the boat spray jobs most always have overspray, tough to paint the oil pan, etc. You will no doubt miss spots if it's left in the boat and you will make a mess of the bilge with the wire wheel and wire brush getting the rust and loose paint off.

Do you have pics of your motor in the boat?

That motor above looks great.





Drake Engines in N.Y. did that paint as part of a complete engine rebuild. $1-1.5K per cylinder. I hate to think what it would cost to ship a 850 lb. engine across the continent and back again.

http://www.drakeengines.com/index.html

I've made huges messes while reconditioning this boat. Nothing drop cloths and vacuum cleaners can't handle.
 
"1. Rust removal"

Wire brush and Ospho.

"2. Primer"

Zinc chromate.

"3. Engine paint"

2 part poly.

"4. Specific paint sprayer recommendations"

Preval sprayers. http://www.prevalspraygun.com/

One way, at least on cooler surfaces, to keep the brass tubing looking good, is to coat it with hair spray. Not sure how it would work on an engine.
 
Thanks for the Ospho recommendation. I just looked it up on the web. That's the kind of stuff I'm looking for because it's impossible to wirebrush 100% of the rust away from pores in the gray iron.

I've had very good luck using varnish on bright brass for some deck hardware. Hair spray is similar. An epoxy clear coat may work well on the engine parts.
 
with all the restored cars in your area there must be a local shop but why bother if it's innards are still in good shape
 
That's what I figure. If it's not broke, don't fix it. I know Sierra Boat up at Lake Tahoe has engine connections.

I saw a guy doing some gelcoat repair at a boatyard a couple of years ago and he used something that looked similar to the Preval spray gun. I think those hold about 8 fl. oz. at a time and may fit the bill perfectly.
 
The best and easiest I have found is Rustoleum (spray can); it is available in colors; I used blue on my Chrysler 330. One can is more than enough for one engine. First wipe down the engine with diesel; this brings any rust to the surface. Now start the spray. It takes only c. 15 minutes.
 
+1 on Rustoleum. Wire brush as much of the rust off, wash with lacquer thinner, brush or spray the paint. When I built my small block Chevy for my boat, I prepainted some parts with a spray can, and brush painted others. After it was fully assembled, I swiped a 1/2" artist brush from my missus, and touched up all the bolt heads and missed spots. You can't tell by looking at it, what was brushed and what was sprayed. Touch ups later blend right in, too.

Larry
 
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