I contacted my friend Ken who is a metallurgist / engineer regarding the Ford OHO news release claiming that the 427 blocks made after mid - 1972 were improved due to additional chromium and controlled phosphorous. Here's what he said about it:
"On your question of the metallurgy of cast iron blocks, sulfur and phosphorus are both undesirable elements that reduce strength and ductility. However both increase the machinability of cast iron and steel by promoting chip breakage. If these elements were too low, the metal would be gummy and the chips would not break. Phosphorous forms a low melting phase with iron. If the iron gets too hot this phase will melt and you have a catastrophy. This phase, being lower melting point, is the last to solidify and ends up in the grain boundaries of the iron. All metals are made up of grains. Too much of this will reduce the strength. Therefore, by lowering and controlling the P content, the tensile strength is enhanced."
1912 Model T Ford touring Salmon (ugh!)
1913 Model T Ford Touring original Black paint
1915 Model T Ford Roadster Black
1915 Model T Ford touring Black of course!
1967 Cougar GT 390 Cardinal Red / Black
1968 Cougar GTE 427 Augusta Green / Saddle
http://www.supermotors.net/vehicles/registry/15029/50071-2
