Color of Engine Block ?

[bpossel]

 :?: What is the correct color of the engine block?

With my IP off the engine, I am doing some cleaning on the engine.  Under all of the 30+ years of dirt, the engine block looks redish, orange.  See attached picture.
Bob

Download Attachment: engine1.jpg
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bpossel
Memphis, TN.
1971 280SL
1997 E320

[Cees Klumper]

This redish/orange color I believe is the original primer color. When Joe Alexander and I rebuilt my engine last year, this is the way the block came back from the machine shop (Fowler Engine in Columbus, OH) - the hot-tanking took off the black-colored finishing paint. Joe then painted the block semi-gloss black.

Cees Klumper in Amsterdam
'69 white 280 SL automatic

[Benz Dr.]

The red colour is actually red glyptol. I think this is also called red lead and is also found on the inside of the block at the bottom of the cylinders. I believe the idea is to seal the block so that engine oil will run off the cast iron faster.
Some blocks are red right from the factory. These are usually replacement units and may not be painted. There will be no engine number on the side of the block or it may be there but the numbers will be a different size or shape because of standard NA number stamps being different than MB.
Primer will be removed during the hot tank process but red lead won't because it's not paint. Clean the surface with wire wheels or any other tools and remove all traces of rust and anything loose so that the cast iron has a shine to it. Several coats of a gloss black paint and it will look really good. The front of the block was left not painted but I think it's best to paint or rusting can start there.
Note: don't paint where you will be using a gasket like the water pump housing. A painted surface is too smooth and won't allow the gasket to seal properly. Clean these areas ( this why they didn't paint the front of the block ) before you install any parts or you will have a leak later on.

Daniel G Caron

[bpossel]

Hi Dan,

I know that my engine is original.  All #'s match my data card.  So, are you and Cees indicating that the black layer of top coat paint has come off?  What I am seeing is the bottom primer?

Thanks!
Bob

quote:Originally posted by Benz Dr.

The red colour is actually red glyptol. I think this is also called red lead and is also found on the inside of the block at the bottom of the cylinders. I believe the idea is to seal the block so that engine oil will run off the cast iron faster.
Some blocks are red right from the factory. These are usually replacement units and may not be painted. There will be no engine number on the side of the block or it may be there but the numbers will be a different size or shape because of standard NA number stamps being different than MB.
Primer will be removed during the hot tank process but red lead won't because it's not paint. Clean the surface with wire wheels or any other tools and remove all traces of rust and anything loose so that the cast iron has a shine to it. Several coats of a gloss black paint and it will look really good. The front of the block was left not painted but I think it's best to paint or rusting can start there.
Note: don't paint where you will be using a gasket like the water pump housing. A painted surface is too smooth and won't allow the gasket to seal properly. Clean these areas ( this why they didn't paint the front of the block ) before you install any parts or you will have a leak later on.

Daniel G Caron

bpossel
Memphis, TN.
1971 280SL
1997 E320

[Benz Dr.]

It was probably apart once before and hot tanked. No one bothered to paint it when they put it back together. I've seen this more than a few times.

Daniel G Caron

[bpossel]

Thanks Dan!

Question...  I am not pulling my engine at this point.  Would you suggest to go ahead and just paint the areas that I can reach?  Brush it on?  It would slow down the rust....

Thoughts?
Bob

quote:Originally posted by Benz Dr.

It was probably apart once before and hot tanked. No one bothered to paint it when they put it back together. I've seen this more than a few times.

Daniel G Caron

bpossel
Memphis, TN.
1971 280SL
1997 E320