sump lining peeling

I don't know what the answer is, but I did read this thread a while back, and they discovered the same thing. Perhaps they could help out.

http://www.ferrarichat.com/forum/365-gt4-2-2-400-412/253362-oil-sump-front-timing-case.html

 

I have seen a post somewhere where someone is painting a gold coating into a sump and casing. I think it was to seal the porous aluminum and yes it was to replace the original coating. More than that i cant recall.

 

First, this issue has been in the engine for a long time with little detrimental impact. When the "coating" was applied to the inside of the engine it probably had some bubbles and voids that did not flow out as it dried. As the engine oil degrades, nitric and sulfuric acids are formed from combustion byproducts and suspended in the oil. If the oil changes have too much time between them and there is little use these compounds drop out of suspension and find their way to the lower surfaces. Any imperfections in the surface finish will allow the acid to permeate the finish and attack the aluminum.
If you have ever restored any aluminum grille pieces that were anodized you saw tiny dots on the aluminum that would not clean up. The only recourse is to de-anodize the part. When this is done the tiny dots now look like much bigger pits. When the "dot" was formed by hitting a small piece of debris it fractured the anodizing allowing atmospheric acids to get into the aluminum. Then the aluminum gets eaten away under the anodized surface.This wasn't noticeable before refinishing started. The molding needs to be surfaced (sanded and polished) to remove the pits before it can be anodized again.
On the sump, oil, the "sealer", and the natural aluminum oxide layer on the surface provide protection. Dirty oil attacks the barriers. It is a good reason to change oil before putting the car up for long periods of non use.
Before re assemble, clean the interior surface without disturbing any of the finish that is intact. The "flaking" happened after long periods of non use with dirty oil. The agitation from the oil flowing around in the sump knocks the "flakes" loose.
During use, keep the engine interior as clean as possible. Use a good oil that will keep all contaminants in suspension and change oil before hibernation. Oil is a lot cheaper than engine parts.
It is an unfortunate fact that these cars all spend an inordinate part of their life in hibernation. The first ten years no one worried about this problem. As the cars age, maintenance gets more involved because of the aging factor. This is just one of the common issues with old cars.

 

http://www.ferrarichat.com/forum/vintage-thru-365-gtc4-sponsored-vintage-driving-machines/314913-engine-internal-paint.html

The V12's engines were coated internally to seal the castings. I would think that the difficulty in re-coating it properly would be greater than the benefits, so I would leave it as it is.

M

 

+1

 

The answer to why the castings are painted is here:

Dino 246 Restoration Blog: More investigation: The three 'P's' of restoration.

Re-doing the paint is a ton of work but it ensures no leaks with the engine. The other option is to have the casting pressure infused with silicone which again works perfectly but is costly.

 

I discovered the same thing back in 2007 when I pulled my sump to replace the gasket. And somehow, I missed Godspeed's thread back in Aug. 2009.
Porous, huh It hasn't dropped a drop since
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