The name HEMI refers to the shape of the cylinder heads. They have a hemispherical design.

It was a Chrysler that was the first to have a HEMI. This was in 1951, and it was a new line of V-8 engines.

A 5.7 HEMI has 350 horsepower. There is one horsepower per cubic inch.

Chrysler has built three different HEMI engines. The first one was called the Chrysler FirePower Engine.

No, Chrysler is not the only manufacturer of the HEMI. Many other auto manufacturers have mimicked the design.

Chrysler trademarked the name HEMI. Before that, many others had manufactured the engine, but Chrysler had dibs on the name.

A HEMI engine can only have 2 valves. These valves are quite large, and they must be heavier than those in a multi-valve engine.

It's the cylinder heads which give the HEMI its name. They're hemispherical in design and shape.

The combustion chamber resembles the thick peel of an orange. That is because the piston crown is domed and protruding.

In the HEMI, the intake and exhaust valves point in different directions. That means that it needs a large, wide cylinder head.

A HEMI engine is incredibly wide. That's why there are only so many cars that it can be installed in.

Chrysler referred to it as the Double Rocker Head in the 1950s. This was in reference to the complexity of the new engine.

The first experimental HEMI was produced during World War II. It was for the Republic P-47 Thunderbolt fighter aircraft.

Chrysler and Continental actually built a HEMI for a World War II tank. It was called the M47 Patton tank.

These were all names for HEMIs. They were from Chrysler, DeSoto and Dodge.

1951-1958 is the period that is known for the first generation HEMIs. You can tell it's a first generation by the rear-mounted distributor.

I hope you got that right:) The HEMI was abandoned in the '60s for the wedge-head B engine. This was a temporary abandonment.

The bore/stroke ratio on an oversquare engine is 1:1. The HEMI is known to be an oversquare engine.

The HEMI enjoyed a revival in 1964. For about six years, it went out of style, but came back!

A HEMI finally got its name as a HEMI in 1964. This was when it made a reappearance on the market.

The 426 HEMI was massive in size and power. That's why it was referred to as the elephant engine.

The 426 HEMI was actually built for NASCAR racing. It was used in a racing Plymouth Belvedere.

The 426 HEMI was used in drag racing. It could stroke to displacements that no other engine of the time could achieve.

Today's HEMIs, known as third-generation, have flatter cylinder heads. They're also far more complex.

Todays HEMIs are not truly hemispherical in shape. But we're still glad that they kept the name!

The 5.7 L HEMI was released in 2003. They were installed in Dodge Ram trucks, 1500, 2500 and 3500.

HEMIs and muscle cars go together like peas and carrots. The 426 HEMI is the design that is used.

Jaguar invented the 6-cylinder HEMI, before Chrysler got their hands on it. Harry Westlake developed it in 1948.

When Chrysler introduced the HEMI, 180 horsepower was pretty phenomenal. It doesn't seem like much now.

The legendary 426 HEMI produced 425 horsepower. Wait. Why didn't they call it the 425? Such a mystery.

The 1951 HEMI got its power from the combustion chamber. It was tremendously efficient for its time.

The HEMI is known for having the spark plug above the combustion chamber, in most cases. The valves open on opposite sides of the chamber.

The HEMI has less surface area, and that means less heat loss. With that, you're able to attain more pressure and power.

The HEMI design allows for large valves. That means that you can get more air pouring through the engine.

The HEMI can never have four valves per cylinder. That's why its use is limited today.