"Del Cecchi" wrote in message
...



I understand the reasons pro and con for forged vrs cast pistons for
automotive applications. It just struck me as a little ironic that after
all the "discussion" over lean burn and detonation and high temperatures
and all that, that this press thing touting the NASA alloy use came out.

I had a little trouble figuring out how this alloy is different from other
silicon containing aluminum alloys that folks have been making pistons out
of for years. But that is a press release for you. I am sure there are
differences, but it can't be figured out from the press release.



The lean burn and the detonation "static" is only from the karen down under,
not from those who are familiar with the engines and work on them on a daily
basis.

You can feel the difference in the NASA alloy compared to an ordinary
piston. It is more dense and scratch resistant and has a different "feel"
when you heft an E-TEC piston. One of the biggest reasons is the more
controlled expansion so the pistons can be fitted tighter in the cylinder
for less "slap" which results in a much quieter motor. That is one of E-TECs
strong points, at cruise and WOT, it is about the same or even quieter in
some cases as a 4-stroke.

Other companies are using the NASA alloy for a number of uses, including
pistons and engine block castings.

Del, you did see that I added a to my previous post when I asked why
not have only one type of piston, right?

Bill Grannis
service manager