The Mack Avenue Engine Plant is one of Fiat Chrysler Automobiles' most historic and prolific factories. It pumped out 260,000 Pentastar V6 engines last year, providing power for everything from the Jeep Grand Cherokee to the Dodge Challenger. FCA and its predecessor, Chrysler, has owned the factory since 1953 and it briefly built the Dodge Viper in the 1990s. It's made engines since 1998 and began building the Pentastar in 2014. We got an inside look at the mighty Mack, helping to tear down a Pentastar engine and then a tour of the factory floor. This is what it's like.