Engine Cosmetics

[rbouch8828]

I am cleaning up my engine now that it is out of the 280SL and I see that the upper part of the block looks like it is painted with aluminum color paint to match the valve cover, while the bottom of the engine is painted black.

Am I correct?

If so, does anyone know what the paint and colors are that are used for both the aluminum color and the black on the engine.

Also, what have people had success with as a polish for the aluminum valve cover? I have a 3 inch air driven polisher that I am proposing to use to polish the valve cover.

I have seen some valve covers that seem shiny as if they had been sprayed with a clear coat. Has anyone seen that and what are thoughts about whether that is acceptable?

Would all the above about the valve cover also apply to the intake manifold?

Many thanks!

Roland

[Benz Dr.]

I use a brass cone on a small angle grinder but having the part cleaned first is a big part of it. The problem is with dirt that can stick to hidden places so generally sand blasting is off limits. You can do it, but you have to make certain that every last speck of dirt is removed after. If you don't have the means to do it, don't.

Aluminium parts are supposed to be left as bare metal. Some guys clear coat them but I can't say how well that works. I use enamel engine paint on black parts but make sure you keep any paint away from parting surfaces. Many parting surfaces ( such as coolant ) will leak with paint on them.

[Rick]

There are those that will spray the aluminum parts with aluminum paint.  I hate it.   It looks "ok" when it first goes on, but  it doesn't take  long to get chipped and discolored.   After  the paint discolors, getting it off again is a pain.  Clear Kotes end up also discoloring.  I would rather have less than pristine aluminum rather than auto parts store type painted aluminum.  I have seen many methods used.   Oven cleaners sometime help.  Scrubbing with lacquer thinner can help.  Using a brass brush can help.  Some have tried bead blasting the valve cover when off.   Some will polish the valve cover, but the shine is not correct or original.  Maybe  somebody had an easy answer that has worked to return the aluminum back to way it is supposed to be? I have not seen an easy answer.

[Shvegel]

I glass bead blasted my parts with superfine glass beads.  When the parts was clean I continued to blast at a very shallow angle to scrub across the surface and polish it.  The next step was a very thin coat of Nyalic clear. One thin Coat is all they want you to apply and it is invisible to the eye. 

https://www.amazon.com/gp/aw/d/B00867RC50/ref=mp_s_a_1_2?ie=UTF8&qid=1500463723&sr=8-2&pi=AC_SX236_SY340_QL65&keywords=extra+fine+glass+beads

http://www.piehtoolco.com/contents/en-us/p11539_Nyalic_Clear_Protectant,_12_oz.html

[mdsalemi]

Maybe  somebody had an easy answer that has worked to return the aluminum back to way it is supposed to be? I have not seen an easy answer.

There is a relatively easy answer, for parts NOT in situ (installed). It's called aluminum cleaner or brightener, and its essential component is either hydroflouric acid or ammonium biflouride, usually mixed with detergents and another acid. One does NOT need to use any bead blasting, though that is certainly an option.

If you have access to industrial chemicals, either online or from an industrial source like a Grainger's, MSC, or similar, look for something like this:
http://www.clean-rite.com/purplepower_aluminum_brightener.html

If you are concerned about the use of strong acid-based compounds, try an alternative like this:
http://www.orisonmarketing.com/aluminox.html

I believe that at most auto parts stores in the USA you can get a product by Meguiars, called Hot Rims wheel cleaner. That comes in three formulas: aluminum, all-wheel, and chrome. The latter is the strong stuff that is acidic and will brighten bare aluminum. The aluminum version is a weaker formula that won't work as well, and the all-wheel is in-between the two.

I do know that powder coaters that specialize in the restoration industry do have colors and coatings that will closely match fresh aluminum and will then keep it that way, if you choose that route.

When my entire engine was sent out for rebuild years ago, it came back (from Metric) looking like it just came off the line at Sindelfingen. I'm assuming that Metric used some kind of aluminum cleaner as part of their process.

[rbouch8828]

What about the section of the block that looks aluminum, where the spark plugs and injectors are, but looks like it is painted and I don't think it is actually the color of the block. Just below that it is black paint for sure.

[mdsalemi]

What about the section of the block that looks aluminum, where the spark plugs and injectors are, but looks like it is painted and I don't think it is actually the color of the block. Just below that it is black paint for sure.

That is aluminum, and the area you speak of is the cylinder head.

[rbouch8828]

Thanks!

I took a closer look and see that what I thought to be painted, is in fact aluminum. Yes, that is the block. There were some dirty areas that made it look like it was painted.

Are the oil filter and fuel filter housings also aluminum, or just painted that color?

[Rick]

There is nothing that looks aluminum that is painted.  It is all supposed to be bare aluminum.   The cast iron parts are painted black

[rbouch8828]

Thank you Rick.

[rbouch8828]

Hello Michael,

Right now I am trying to clean the fuel injection lines. I used the wheel brightener on the engine and it worked much better than the other cleaners I had tried.

However, I tried it on the injection lines and I didn't get such great results.

Any suggestions.

Best,
Roland

[Shvegel]

The injection lines are steel plated with either the original Cadmium /yellow Chromate what is termed "Yellow CAD"  or type 2 Cad plating.   Cadmium is extremely toxic stuff so very few plating shops will use it but the substitute of Zinc / Yellow Chromate or what is termed "Yellow Zinc" is fairly common. 

[rbouch8828]

The injection lines are steel plated with either the original Cadmium /yellow Chromate what is termed "Yellow CAD"  or type 2 Cad plating.   Cadmium is extremely toxic stuff so very few plating shops will use it but the substitute of Zinc / Yellow Chromate or what is termed "Yellow Zinc" is fairly common. 

How do I clean them? The Chrome Wheel Cleaner that worked great on the aluminum parts doesn't do much on the steel injection lines.

What is the right solution to use on the injection lines?

[Shvegel]

if they look brown and rusty they most likely need to be replated.  anything more than a light degreaser will most likely attack the plating.

[wwheeler]

You can use a mild degreaser them to clean them but if the plating is dull or damaged, there is no fixing that. They will have to be re-plated to look show quality. Others have painted them as a alternative to plating. But you will never come close to the correct look with paint.

[bogeyman]

I wet sanded mine - progressive grits up to about 2000. Then I polished with Simichrome.
They look good, obviously not original but an improvement on the rusty appearance.
It's been a couple years now and they have held up well plus when I do get them refinished they are ready to plate.

[Benz Dr.]

I blast them clean and then I polish them with a soft wire wheel. Getting them cleaned and polished is the trick to good plating. The plating shop will clean them with acid before they start and some will clean them for you for a price. My plating guy likes how I prepare my stuff - says it's some of best parts he's seen to work on.