On engine bay detailing . . .

[Jack the Knife]

While waiting on some chrome to be plated, I figured I'd get into detailing some components of my engine bay. I was admiring a photo of Garry's engine bay (and his car is similarly colored to mine), seen here: https://www.sl113.org/forums/index.php?topic=22413.0 and comparing it to my own, attached.

By comparison, the quality in the finish of my valve cover and intake manifold are inferior.

The ignition system lines laying about are hideous -- I was wondering, I wasn't able to fit those into the metal sleeve the old ones went into, yet I see some other SLs where they're neatly inside. I couldn't even squeeze one through. Is there a larger sleeve available on the later cars?

Everything could stand to be cleaned and some things repainted (well, probably most things, owing to that whole "while I'm in there"-itis). And some hoses and fittings replaced...

... but how about that zinc or cad plating! I found someone locally who can do zinc, but cadmium seems to be hard to come by. Is there a master list somewhere for all the components that should be plated? Also, is there a procedure written somewhere for disassembly of all these things without getting fluids and whatnot all over the place? And does anyone see anything in there alarming that I need to check out -- I do note the 'failure mode' of the breather pipe on top of the valve cover which is just open to the air, and I'm not sure why that modification was made. It's ugly, I'd like to find an original metal one, but I'm not sure how that might change things.

[Pawel66]

I am not sure what is wrong with your aluminum parts finish...

What I think would have dramatic impact:
1. Yes, plating of some of the components, e.g. fuel lines
2. Re-painting coolant expansion tank and brake booster
3. Clamps
4. Battery made looking retro (attaching picture of my modern Varta made to look more "appropriate")
5. Not sure if the shock absorber plates are original... anyway: nut and counter nut

[mdsalemi]

I was admiring a photo of Garry's engine bay (and his car is similarly colored to mine), seen here: https://www.sl113.org/forums/index.php?topic=22413.0 and comparing it to my own, attached.

By comparison, the quality in the finish of my valve cover and intake manifold are inferior.

1. At the time of original manufacture probably (though I'm not certain 100%) most everything made of steel in the engine bay was cadmium plated. Some of the parts then further had a phosphate wash over them to give them additional protection which also gave them that yellowish color. Today, it's often replicated in zinc. Cadmium is longer lasting. Seek it out, but you may have to go distant to find it. Contrary to popular believe it is still being done, though harder to find with each passing day.

2. There are many photos here on the forums in the manual, and also check the one of Garry's and thelews has fabulous photos as reference to what should be plated and what "color".

3. A chemical cleaning of your valve cover (NOT mechanical) will give it a fresh look. I'll modify this post when I return home with a before and after photo of mine when my engine was rebuilt. Metric Motors did the work.

4. Many replacement parts, even original OEM (but not NOS) Mercedes parts do NOT come with the correct original finish on them any longer...for example, an automatic transmission filler tube used to be plated, now it's painted.

Cadmium like zinc plating is generally done in a barrel. So, the more you do at the same time, the better.

[rwmastel]

By comparison, the quality in the finish of my valve cover and intake manifold are inferior.

For all these finishes on various parts, do you want to replicate original, or make it how you want it?

Is there a master list somewhere for all the components that should be plated? Also, is there a procedure written somewhere for disassembly of all these things without getting fluids and whatnot all over the place?

No master list, as production parts & techniques changed, evolved 1963 - 1971.

Even surgeons today can end up with blood about the floor and table when the job is done.  You'll get yourself and your garage dirty.  "Grease monkey" didn't come from nowhere.

I do note the 'failure mode' of the breather pipe on top of the valve cover which is just open to the air, and I'm not sure why that modification was made.

Mine was that way when I bought the car.  Too much oil blowing up past the rings into the combustion chamber (burning some oil) and then past worn valve guides, returning to the intake manifold (to burn the rest of the oil).  Makes it hard to tune the car to run well and shows too much blue smoke out the tail pipe.  So, direct it to the ground to bypass evidence and problems from a worn engine.

[Jack the Knife]

I am not sure what is wrong with your aluminum parts finish...

What I think would have dramatic impact:
1. Yes, plating of some of the components, e.g. fuel lines
2. Re-painting coolant expansion tank and brake booster
3. Clamps
4. Battery made looking retro (attaching picture of my modern Varta made to look more "appropriate")
5. Not sure if the shock absorber plates are original... anyway: nut and counter nut

That's really cool what you did to the battery!

In person, the aluminum looks like someone rattlecanned all over it which is exactly what happened, same with the injector lines.

A set of clamps and hoses is on the way! Not sure where those shock absorber plates came from. I had the Mechatronik suspension installed by my mechanic, probably they showed up then.

1. At the time of original manufacture probably (though I'm not certain 100%) most everything made of steel in the engine bay was cadmium plated. Some of the parts then further had a phosphate wash over them to give them additional protection which also gave them that yellowish color. Today, it's often replicated in zinc. Cadmium is longer lasting. Seek it out, but you may have to go distant to find it. Contrary to popular believe it is still being done, though harder to find with each passing day.

2. There are many photos here on the forums in the manual, and also check the one of Garry's and thelews has fabulous photos as reference to what should be plated and what "color".

3. A chemical cleaning of your valve cover (NOT mechanical) will give it a fresh look. I'll modify this post when I return home with a before and after photo of mine when my engine was rebuilt. Metric Motors did the work.

4. Many replacement parts, even original OEM (but not NOS) Mercedes parts do NOT come with the correct original finish on them any longer...for example, an automatic transmission filler tube used to be plated, now it's painted.

Cadmium like zinc plating is generally done in a barrel. So, the more you do at the same time, the better.

Thanks, Michael -- I'll look forward to your comments on refreshing the aluminum. I saw some pics you posted some years back of the engine overhaul, and I admire the work MM does. I searched around and it seems there are some cadmium platers Florida who mostly work in the aviation industry. When I collect all the parts off of the car, I'll catalogue and seek a few quotes..

For all these finishes on various parts, do you want to replicate original, or make it how you want it?

No master list, as production parts & techniques changed, evolved 1963 - 1971.

Mine was that way when I bought the car.  Too much oil blowing up past the rings into the combustion chamber (burning some oil) and then past worn valve guides, returning to the intake manifold (to burn the rest of the oil).  Makes it hard to tune the car to run well and shows too much blue smoke out the tail pipe.  So, direct it to the ground to bypass evidence and problems from a worn engine.

If there's some advised coatings or modifications for longevity or performance reasons, I'm all for it. I do like the look of a nice clean engine. But nothing like chroming the valve cover. I think so long as the engine bay remains mostly stock, it should look and perform its best. And if I'm already paying for cad plating on a few things, then the marginal cost of an additional screw or cap or whatever really is no skin off my nose. I appreciate the information about the breather hose, so maybe I can buy the metal pipe for the look and attach a hose directed to the ground from there rather than reconnecting it to the intake.

[mdsalemi]

Jack, you said: “I searched around and it seems there are some cadmium platers Florida who mostly work in the aviation industry.”

For a variety of reasons that’s the primary remaining use for cadmium plating…

…aside from oddballs like us!

[rwmastel]

I appreciate the information about the breather hose, so maybe I can buy the metal pipe for the look and attach a hose directed to the ground from there rather than reconnecting it to the intake.

Start digging into the health of your engine.  Compression and leak down tests to begin with.  Let us know if any weaknesses are found.

[Jack the Knife]

Jack, you said: “I searched around and it seems there are some cadmium platers Florida who mostly work in the aviation industry.”

For a variety of reasons that’s the primary remaining use for cadmium plating…

…aside from oddballs like us!

I'll be sure to review whoever I find around here, helps to have as many resources as possible...

Start digging into the health of your engine.  Compression and leak down tests to begin with.  Let us know if any weaknesses are found.

Will do, will report posthaste. Maybe I ought to just make a master thread documenting everything I've done.

[mdsalemi]

Jack,

Because aluminum (and zinc and magnesium for that matter) are exceedingly soft metals, the cleaning of aluminum cannot be done mechanically (i.e. brushes and similar mechanical action) but rather must be done chemically.

See these photos of the "before" and "after" of my engine, paying particular note to the valve cover.

When posed the questions, Mike at Metric didn't even really know what "chemical dip" he had in his tanks to clean things. However with some experience I can tell you it was probably something specifically made for aluminum cleaning. You can do a search for both the process of cleaning aluminum and the products in which to do them. Generally they are combined acids and detergents, with hydrofluoric, sulfuric, and or hydrochloric acids and or ammonium biflouride. They are really very nasty things. Search for "aluminum cleaners" and or "aluminum brighteners" and you'll find many products to use...and the best of them contain those ingredients as mentioned. They chemically attack the dirt, oils, grime, etc. leaving a freshly-cast look. Might be a great idea to put a clear powder coat on the surface once you do that!

[Jack the Knife]

Jack,

Because aluminum (and zinc and magnesium for that matter) are exceedingly soft metals, the cleaning of aluminum cannot be done mechanically (i.e. brushes and similar mechanical action) but rather must be done chemically.

See these photos of the "before" and "after" of my engine, paying particular note to the valve cover.

When posed the questions, Mike at Metric didn't even really know what "chemical dip" he had in his tanks to clean things. However with some experience I can tell you it was probably something specifically made for aluminum cleaning. You can do a search for both the process of cleaning aluminum and the products in which to do them. Generally they are combined acids and detergents, with hydrofluoric, sulfuric, and or hydrochloric acids and or ammonium biflouride. They are really very nasty things. Search for "aluminum cleaners" and or "aluminum brighteners" and you'll find many products to use...and the best of them contain those ingredients as mentioned. They chemically attack the dirt, oils, grime, etc. leaving a freshly-cast look. Might be a great idea to put a clear powder coat on the surface once you do that!

Beautiful work on your engine, I've never seen the before. Researching what you've recommended and I like the idea of the clear powder coat -- Michael, I appreciate the time you've taken for advising, thank you.

I've located a cad plater and a friend and fellow 113 owner who is restoring a classic 911 is going to go in with me. Will report on the results and review the fellow if he is good.

[jeblack123]

Good afternoon. Can you share the name of your CAD plater? I have any extra set of fuel lines that I would like to have plated and replace the current ones on my 280.

Thanks, in advance,

James (Eddie) Black

[wwheeler]

I tried powder coating aluminum with clear and found it to have mixed results. Sometimes the aluminum can bloom underneath the powder coat which results in cloudy spots. I instead use Tiger/Drylac Bengal silver as a color for the powder coat. https://www.tiger-coatings.com/us-en/shop/show/149-99999 Not exactly the same as the natural aluminum but close enough for me. It will never change in appearance and is super easy to clean. I did all of the cast aluminum parts in the engine bay and has a uniform appearance. (see Ponton oil filter housing attached). I did the throttle body though with a ceramic silver and only because the heat from powder coating created too much off gassing (pimples). Again, not perfect color but won't change and easy to clean.

Aviation is the primary user of CAD plating because of 1) higher cost 2) more durable than zinc 3) and most importantly has a much thinner build up than zinc. in other words will not change dimensions for a critical fit hardware.   

[Pawel66]

Beautiful throttle!

[wwheeler]

Here is the 220SE Ponton throttle body with the same silver ceramic coating.

[mdsalemi]

I tried powder coating aluminum with clear and found it to have mixed results.

As there is with plating, there's a huge difference between the DIY stuff done at home, and the very experienced professionals. Unfortunately my go-to guy, Exotic Coatings of Romulus, Michigan closed down his powder coat business a few years back much to the dismay of the legion of followers he had. He had the requisite skills for aluminum and knew all the pre-treatments.

Aluminum just requires different techniques but can be successfully powder coated with the correct pre-treatments and cleaning processes. However, a good aluminum paint product will yield great looking results particularly on rough castings.

[wwheeler]

Powder coating aluminum isn't the problem. The problem can arise when done with clear. With a colored powder coat, it covers any blooming that can occur underneath. Blooming is never seen. Clear does not have that ability. Aluminum is a very difficult material to coat with heat or even with electroplating plating. And no, it was a professional that tried powder coating the throttle body that blistered, not DIY. Some base metal alloys are just so bad, they cannot be heated for powder coating without off gassing underneath. 

I am not saying aluminum cannot be powder coated successfully with clear, only that it may cloud over time. Just know that it can happen.

[Jack the Knife]

Well folks, parts are going to the cad plater tomorrow. I don't want to get too crazy with basically disassembling the whole engine compartment and taking in every nut and bolt, but all the main steel parts are being plated (al hard lines, larger fasteners, some pieces off the injection pump, all throttle linkages). I am also very pleased with the performance of Spacecoast Plating near Melbourne, Fla. The only two pieces that needed some work on my car (well, other than my dented bumper) were the interior rear view mirror and the trunk handle, both with pitting. All four pieces look brand new, now. Just need to either get a new mirror or have it re-silvered...

Having my modified driveshaft for the 5-speed swap painted alongside the various black components in the engine bay in chassis blank, and looking now for a decent powdercoat place here for the valve cover, air intake, and throttle body.

I am not saying aluminum cannot be powder coated successfully with clear, only that it may cloud over time. Just know that it can happen.

I've had that experience with aluminum wheels, sadly.

[wwheeler]

Just to be be clear when you CAD plate, you have the choice of chromate color. The most common ones are clear (sliver) or yellow which is what you see in W113 engine bay pictures. See attached. Yellow CAD came to be used with Mercedes starting in the 60s. Earlier 50s Pontons used only clear cad or black oxide.

As discussed, CAD is more durable than zinc but more costly. Zinc plated parts use similar chromate colors as does CAD. But in general, zinc plated parts will have more of a rainbow effect than CAD.

[Esmo]

I had the radiator recored ,power coating was part of the process also the header tank . The other black parts were degreased and Xylan coated ,thickness 20 mic then heated at 140 deg for 20 mins low bake. The zinc plate was colour passivated at 5 microns . Regarding bolts and washers it may be a better option to buy new .

[wwheeler]

I never replate split lock washers for two reasons. 1) they are a standard spec and do not vary. 2) and most important - spring steel parts can suffer from hydrogen embrittlement during plating and can snap during use. There is a process to negate that, but it is more cost. Not worth it for these pieces.

I reuse and replate many flat washers because the originals can vary in thickness and size. If the old washer is a standard size and I can find the correct chromate color, I'll use new.

Nuts are the same deal as flat washers.

Bolts - there are many variations in bolts including head size and original markings, bolt strength and some have unusual configurations. Unless the bolts are damaged, I usually replate these.   

[stickandrudderman]

Instead of discharging oil from the crankcase breather out on to the road, it's much better to discharge it into a catch tank which can easily be made from any old container. This allows one to dispose of the oil respectfully as and when it is full.
I have all aluminium parts vapour blasted.
Cad plating is now the preserve of specialist platers due to the negative environmental impact. Usually that means for aerospace components only and a special licence is required. Here in Europe any electroplater found to be cad plating without the special licence will find himself in very deep water very quickly and so all that I've spoken to here in the UK will refuse classic car work.
Zinc plating doesn't last anywhere near as long as Cad.

[zoegrlh]

Yes plating does not last. I had yellow cad plating about 15 years ago, and now will need to have a few things replaced. When I plated some 15 years ago, I asked shop to do light yellow cad plating, because I wanted the patina look, not the yellow, yellow look almost like gold look. By having the platers take the tubs out of vat early, not c as much plating thickness accrued. You will have to decide if you want the yellow yellow yellow look or the mild yellow look.

[VikDasor]

I have just had all my aluminium parts vapour blasted and the results are impressive and have also just collected my front end suspension parts after cleaning, blasting, zinc primer treated and then powder coated.  I also contacted quiet few places to have cadmium plating done here on the UK but no one wanted to take on the nut and bolt restoration so I had to go for yellow zinc plating and I am hoping it comes out well. Exhaust manifolds also done in dark grey cerakote ceramic.

[VikDasor]

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[VikDasor]

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