Aluminum cools faster than cast, which is why many compressors and
air-cooled engines of all flavors with iron inserts have aluminum cooling
fins.

Though it may have been a buy recommendation for you, it does have its
drawbacks.

"Barry N. Turner" wrote in message
...
Well, it was definitely Campbell-Hausfield that made mine. I
double-checked
today at lunchtime. The compressor on mine is cast iron instead of
aluminum
as many of the other brands are. That was a selling point for me.