230 SL Engine Finishes Advice Needed and Brake Cylinders

[Ron500E]

After a somewhat long delay, due to the purchase of another damn car, I've started on my engine.
Does anyone know, or know of a book, that shows the correct finishes on the various parts?

Example: what items are Cad plated, what items are left in natural aluminum, what parts are painted cast iron or left unpainted, etc., etc.

Also......
I need a good source and advice for the rear brake cylinders, genuine MB or after-market? Does anyone know the ATe part number?

Thanks,

Ron

[Benz Dr.]

Pretty straight forward really. Just about every harware piece that is steel is zinc chromate.  The power steering pump and bracket are black as are the fan pulleys. Aluminium is left bare and lightly polished. Engine block is always black despite pictures showing them as being red. That color is a factory applied red coating that goes under the black paint.  It shouldn't be too hard to follow what's already on your but do ask if you're not sure.

[Ron500E]

THANK YOU so much !!!
Kind regards,

Ron

[wwheeler]

Chromate is not actually a color but rather a protective coating that is applied to the zinc plated part. Chromates come in different colors such as yellow(gold), clear (with a slight blue tint) and black. So yes those zinc plated hardware bolts and nuts are coated with a clear chromate.

The chromate's main job is to provide a protective surface for the zinc. Zinc is very easily damaged by acid which includes from your fingers. Coca Cola will do a number on unprotected zinc.

Yellow zinc, as it is commonly called, is the primary plated surface on these cars. Note: you can also have yellow and clear CAD which again is a colored chromate but using Cadmium, not zinc.

 

[Benz Dr.]

I know that but zinc chromate is much more readily available and considerably less to have done. There isn't one place in Ontario that uses cadmium due to its toxic nature. Frankly, I don't like the look of it and it's not even close to what it originally looked like IMHO.
 Maybe it's the place I sent it to but it came back looking too dark and more gold/bronze than anything else. However, I've seen other cars with the same general hues so I think that's what it looks like and I'm not convinced it's even correct.
Since I can't get cad plating done locally, and I can get zinc done that's very high quality, I'm going with that. I'm more than sure it's the industry standard these days anyway.

[Ron500E]

So what would be original in 1965, Yellow Cad or Yellow Zinc or Zinc with a Clear Cad Covering or..... ?

I have a good relationship with a local Cad plater so adjusting the color is not a problem, and they do REAL Cad !!!!


Thanks,
Ron

[wwheeler]

For '65, yellow zinc is probably more correct as the use of CAD was fading at that point. That being said, I would always use CAD over zinc if I could. CAD is far more durable than zinc and produces less of a build up. That is important for close fitting parts and even threads. That is why aerospace still uses CAD.
CAD is at least twice as much and in my area about $130 vs. $60.

My place does not do black CAD and so for black oxide type parts, I am forced to use black zinc. Black zinc is still more durable than black oxide.

For my cars, I try to balance between originality and durability. Many times they are at odds with each other such as this case. I am pretty sure yellow zinc is correct, but yellow CAD is close enough that most people can't tell and more durable.

My own personal choice.