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MG Midget and Sprite Technical - Cleaning and painting an engine

I'm just wrapping up a 1500 engine rebuild for a friend, and am considering repainting it before installation. It's basically just dirty, with a bit of oil leakage. What's the best way to clean the thing up, and what paint would you recommend?

Thanks! By the way, photos here:

Teardown:
http://www.flickr.com/photos/safety_fast/sets/72157632793749760/

Rebuild:
http://www.flickr.com/photos/safety_fast/sets/72157633379021853/

-:G:-
Gryf Ketcherside

Clean with degreaser/brake cleaner and a wire brush.
Paint with any ratle can.

You can do al kind of difficult stuff with priming of powdercoating but why bother?
Ratle can finish is nice it stays on for ever (if you degreased properly) and it is almost like the factory has done it
Onno K

Thanks, Onno.

Yeah, getting it completely degreased is my main concern. Do you need to clean off the degreaser before painting, or does it evaporate off pretty much on its own?

Definitely rattle can... we're not going for concours points here, I just want it to look like it's been rebuilt. ;-)

-:G:-
Gryf Ketcherside

Depends on the cleaner.
The arosol brake cleaner evaporates since it is mostly ethanol based othes may need a hose down afterwards

Some consider the paint job as the rebuild.....
Onno K

Easy off oven cleaner does a great job of degreasing and stiff nylon brushes...the last step to completly clean is spray can brake cleaner...used heavily... it will evoperate off

The engine degreasers work... but leave there own residues

I like easy off oven cleaner esp the fast acting version... spray it on on hose it off...garden hose or pump up grarden sprayer

As to painting...I havnt had much luck with longivity with rattle can paint about a year at best before it fades, and strecks and looks bad...granted it dosnt peel, but might as well....thats why I went powder coat, and never regretted

My advice 2 directions

1. A high temp flat black bbq grill paint... will look good and hold up well... but no other color and no other finish... the bbq high temp paint was.made for this application....lowes or home depot

2. Go to a Automotive paint store and get the paint that john mangles uses on his engines... have the paint store put the paint in a rattle can....its an autobody paint...but im not sure what if its an enamel or a top coat clear coat....its not all that expensive

If you do go rattle can off the self avoid dupee and rustolium brands and avoid strong color paint like red, orange, blue...they turn.about 6 shades lighter with in a year and.look really bad

Ideal color would be light colors ..baby blue, white, lite LITE mint green, pink

The best call would be steel gray

Of all the spray can rattle... high temp flat black BBQ paint....they do make other colors of bbq paint... but they dont look good, the red is more burnt clay red as an example

Thats my real life experiance....maybe there are other engine paints that will do better the dupee and rustolium...I dont know what... its a gamble...but avoid dupee and rustolium hi temp paint

Prop
Prop and the Blackhole Midget

Gryf,

Here are my suggestions. A degreaser that I like is Awesome that you can get cheap at the dollar stores. Shoot if up with that, and then hopefully you have a pressure washer (I have a cheap electric one, $70 that I got at Lowes). Blow it down with the pressure washer. I see you have some rust on the engine.

Then I would use Scotch Brite on the sheet metal parts like the valve cover, timing cover, and oil pan. It works much better than wet/dry sandpaper because it is thicker and gets into irregular shapes better. Also, you can use it in conjunction with a solvent.

Prop recommended oven cleaner. I used oven cleaner (Kroger house brand) on the wheels of my Volvo to remove old brake dust deposits from the wheels and I noticed that it removed the rust from the calipers. So, that should be a good recommendation.

Finally, I would blow it down with something like the brake cleaner or maybe xylene shot from a paint gun.

I have used automotive grade primers from a spray can with good results. I haven't used spray can engine paints for years because they don't seem to hold up well. Except for the ex manifold engines don't get all that hot.

For a topcoat I use a high-grade industrial enamel, and I shoot it with a paint gun rather than from spray cans. Give it two coats. Harbor Freight sell a touch-up spray gun real cheap that is ideal for the job. Prop recommended flat black, but I would avoid flats because the gloss will be easier to clean and won't have a tendency to let oil soak in.

If you have to use spray cans for the topcoat you might consider the Rustoleum professional grade that comes in larger (15 oz?) cans. It only comes in a few colors, but gloss black is one of them. I have used that with success on accessories though I don't recall painting a block with it.

Charley
C R Huff

Well, I made several editing changes, but it seems they did not take.

The note about rust in the first paragraph is supposed to be in the paragraph about the oven cleaner.

Then, I meant to add that a leaf blower is a nice way to dry water off after washing.

Also that cheap touch-up gun I mentioned is (I think) less than $10.

Charley
C R Huff

Excellent point on the flat being.stained.by oil...I hadnt thought of that... but I sure dont like glossy on an engine ither as in a year it fades bad, thats.from rattle can...

Prop
Prop and the Blackhole Midget

I use a household oil based gloss paint. OK, it takes a while to dry and harden up properly but when it does it gives a nice smooth gloss finish that lasts and lasts. Put on with a brush it flows nicely to form a lacquer -like coating that smooths over casting irregularities. And the main benefit is that being oil based it doesn't react with any oil or oil solvent residues that might lurk in places after cleaning down.
Guy W

How does (-- does? --) painting the block and head affect heat dissipation?
Lawrence Slater

I never noticed any effect with heat dispenstion

The real issue you have to take into account....electric grounding.

Prop
Prop and the Blackhole Midget

All very good advice, thanks!

-:G:-
Gryf Ketcherside

I'm not convinced that painting an engine, has no effect on heat dissipation. Some paints retain heat, and some help to dissipate it. Just as painting a radiator in the home, might cause the radiator to be less efficient, depending on the thickness of the paint and the paint used.

Would you paint a heat sink? No. To do so would reduce it's effectiveness. So surely if you paint an engine, won't you effectively insulate it, unless the right paint with the correct properties is chosen?

Doesn't the same argument that applies to insulating manifolds and exhausts, apply to engines? If there is a heat build up, the heat has to escape somewhere.

I don't know the answers to this, just asking.

Lawrence Slater

Great....now im wishing I hadnt painted my crankshaft....hahaha

Prop
Prop and the Blackhole Midget

This thread was discussed between 15/05/2013 and 17/05/2013

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