OK - just curious. I keep seeing these ads about whether or not a truck engine has a hemi - yet I really don't know what it is or why I might want one. Anyone care to enlighten me? Bradford P.S. I'm not actually in the market for a new car, but I'm sure it would enhance my sports television viewing if I knew what these ads were talking about.
In short, a hemi engine's cylinder heads are shaped in a half circle (a la a HEMIsphere) while a normal engine's are squared off.
What a "Hemi" is has been adequately explained by others. It was not a new idea even when Chrysler "introduced" it in the 1950s. Tatra were using hemi-head engines from the 1900s, Peugeot from the 1910s, Citroen from the 1930s, Jaguar and Alfa Romeo from the 1940s, etc. As for the thornier question, why you'd want one, I can't see a reason. It's an iron-block tractor lump with overhead valves that is oversized and burns the wrong fuel. The automotive equivalent of expensive fused-front petrochemical suit. No European, Japanese, or Korean marque would even think of equipping one of their cars with such a primitive and pathetically wasteful motor. Even the dastardly new lorries on the American market, like the Nissan Titan and Ford F-150, have modern engines with overhead cams and multiple valves these days. Peace, JG