Join Date: Sep 1998
Location: Tucson, AZ, USA
Re: Ford's Super Duty Powertrains...
One other aspect of a steel piston is that its heat transfer is less than aluminum and keeps heat in the chamber and not in the oil. That extra heat is a benefit for a Diesel. And the thermal expansion rates for steel would be less than many typical piston alloys, allowing or a tighter fit.
I had a chat with the chief engineer from a piston company and he oddly noted that the piston temperatures in a Detroit Diesel (2 stroke) were higher than the melting temperature of aluminum pistons.