Why would they do that? Surely the environment in the compression chamber is too harsh for lead? What are the benefits if any?
The original 1966 build log clearly shows the following:
During the stripdown of my engine I was surprised to see a white "bloom"/powder on the crowns of the pistons (the engine had lain untouched for 40 years or so) which did have the appearance of lead oxide. Although the white deposits were quite thin and easily removed simply by rubbing, the piston crown still has a dull finish which could be a lead coating? The coating seems to be limited to the piston crown.
Here is a picture of the pistons before they were removed from the engine:
By way of comparison, here are the cleaned-up pistons temporarily reinstalled in the engine:
The picture doesn't show it very well but the crowns have quite a dull finish.
Edited by Nev, 22 April 2012 - 08:44.