For 2012 the SRT lineup from Dodge is getting more than it’s own SRT brand recognition, it’s getting new motivation, literally. The new SRT lineup will include the Dodge Charger, Dodge Challenger, Chrysler 300C, and Jeep Grand Cherokee. All four SRT cars will receive the new 6.4L/392 HEMI from Dodge, though the engine will be applied slightly differently for each car.
We found the great video you see below over at RedLetterDodge.com, and in it Gary Rogers, head poobah of the engineering group, gave an overview of the big changes between the outgoing 6.1L HEMI and the new 6.4L HEMI.
To begin, all versions of the engine will make 470HP and 470 lb.-ft of torque with the exception of the one for the Grand Cherokee, which will make 5 lf.-ft less. In the Challenger application peak power is made at 4200, which is 600 RPM earlier than the 6.1 that it replaced. It also receives more low-end grunt making 45 lb.-ft of torque more ant 1600 RPM than the old 6.1L motor.
All cars feature bigger intake and exhaust valvles, both of which are larger in diameter by 1.5mm and feature hollow stems for reduced weight and improved valve train dynamics. In addition, the exhaust valve is sodium filled for improved cooling. The “active” intake manifold is now lighter as it’s made made of composite vs. the the aluminum intake used on the 6.1L HEMI. It features dual runners as well, with long ones used under 4800 RPM for low speed torque, and short runners used above 4800 RPM for high speed power.
The engine also features variable cam timing, 4-cylinder operation for cruising fuel economy, a forged crankshaft, new windage tray and oil pan, and a bump in compression up to 10.9 over 10.3 from the outgoing 6.1L engine.