What makes a hemi so powerful and desirable?

Question

I understand it's short for hemisphere and the intake and exhaust valves are on opposite sides, but I still don't understand it's workings.

Answer 1

Trying to make this as Simple as possible.
At the bottom of the head and the top of the cylinder, is an area called the combustion chamber. That's where your fuel and air meet with the spark to form an explosion to send your piston to the bottom of allowed stroke. Allowed stroke is the distance you crankshaft and piston rod control the distance the piston goes up and down.
With that out the way back to the combustion chamber.
The HEMI engine is short for hemispherical which is the shape of the combustion chamber. Noted to increased torque and horsepower with smaller displacement.

what make them desirable, is the name that is synonymous with history. in 1967 -1969 Nascar was dominated by the 426 HEMI. then the HEMI was then banned from racing. Mopars claim to Nascar fame.

Answer 2

It works just the same as other engines, basically. The big difference is that the hemispherical head design mixes the air/fuel better and the plug is in the middle of the combustion area which promotes a better burn.

Answer 3

Marketing. That's it.

Of all the various engine technologies, "hemi" is pretty minor. Mainly its use today amounts to playing on nostalgia for people who remember the 1970s muscle car days.