Digging Into The Dart’s Tigershark Engines

In just ninety-five weeks, Chrysler Group LLC engineers put together an all-new family line of engines. Named the Tigershark, the four cylinder has made its debut under the hood of the 2013 Dodge Dart in either 2.0 or 2.4 liter form. In what was the shortest interval between program approval and product launch, Chrysler managed to produce what they are calling their “most refined 4-cylinder powerplant ever.”

With not much time to go from piece of paper to piece of machinery, the engineering group responsible for the Tigershark had to implement a new kind of testing. “The extremely compressed timing required shrinking the window allotted for dynamometer calibration,” said Glen Macfarlane, Tigershark’s chief engineer. By “synchronizing multiple test cells via a complex design of experiments,” Chrysler was able to produce, test and properly evaluate their powerplant. Starting with a base made from the Fiat-shared World Gas Engine, both Tigersharks use enough new materials to be rather unique. The 2.0 only contains 12 percent of previously existing parts while the 2.4 is 89 percent all-new.

Each mill uses an alloy construction with cast-iron cylinder bore liners. The bore is the same 88 mm for each but the 2.4 uses a longer 97 mm stroke crank compared to the 82 mm 2.0. To reduce friction, diamond coating was used for the piston pin and the rings are low-tension pieces. Variable valve timing can be found on both the SOHC and DOHC engines so that 160 and 184 horsepower can be had respectively.

Source: Dodge