What do you do about this?
 

Aluminum is turning yellow and corroding on the engine even though it is just sitting. Do I just polish it?

Looks like oil to me unless you clear-coated or aluminum paint on the heads and the coating started to burn off. Aluminum dulls and the forms white aluminum oxide on the surface.

Spray it with aluminum wheel cleaner and lightly scuff with a green scotchbrite. Rinse with clear water in a spray bottle and wipe dry. The apply a liberal coating of WD40 on all the aluminum parts and retreat periodically.

Looks like oil to me also. Therefore I'd start with just a shop or terry towel soaked in brake clean, lacquer thinner, or acetone and see if it doesn't lift off. These won't change the surface texture and more aggressive attacks will.

Unprotected aluminum corrodes quickly. Once you have clean the oil off, apply metal prep( a phosphoric acid solution) then apply Alodine to stop future corrosion.

Looks to me like iron laced dust rustin!:bolt:

Any idea what Alodine would do the the appearance of the aluminum? I'm assuming it would change the finish.

It’s not oil. The engine hasn’t been run in months it’s not oil.

It's rust. The heads are blasted with metal during the manufacturing process. Sometimes specs of metal are embedded in the aluminum and then rusts.

So what do I do? My machinist said a scotchbrite pad no cleaner

Correct, the only way I have been able to keep it from happening was to use a scotchbrite pad with CLR on it.

I've never had much of a problem but seemed to have luck with brake clean and a silver wire brush.

Have you tried what he suggested?

Can’t go out. Waiting on scotchbrite from amazon LOL

I assume you could use Iron Out.
Or Sodium Hydrosulfite powder if you have access to it.

Get a loaf of bread too while at Walmart!

I have two loaves of bread and two gallons of milk. I just ordered some scotchbrite pads and wd40 from Amazon. I also have 48 rolls of TP not because I am a hoarder but because I am on the Amazon subscribe and save program and we weren’t here much last month so we got that month and this months LOL

Paul is right, it is embedded rust. Had the same thing happen on my rpm intake and it keep getting worst as time went on. Never could find anything that would clean it up, so i just used high temp aluminum engine paint and sprayed entire intake. It turned out great, looks new again.

X2 paint it. Had this problem with my intake years ago and painted it engine color. Did the same on this engine-intake and heads. Paint stays on aluminum heads shockingly well

Hit it with a small brass bristle brush

x3. The Dupli-Color 1615 Aluminum Engine Paint is the right 'tone', not real shiny or anything, and looks great. Easy to touch up too.

I usually etch intakes, but it's tough to do the same on heads. Wipe it with acetone, let it dry, and shoot them.


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