2006 Dodge Magnum SRT8 Preview

After boring out the cylinder diameters by 3.5 millimetres apiece, the modified block was reinforced and coolant flow increased. A

Chrysler Group's SRT team raised the 5.7-litre HEMI's 340-horsepower output by 85 ponies the good old fashioned way, by increasing displacement. (Photo: Trevor Hofmann, Canadian Auto Press)

forged steel crankshaft was integrated to minimize vibration, while stronger powder-metal connecting rods capped off by oil squirter-cooled floating-pin pistons were attached. Underneath, a modified oil pan is said to reduce oil foaming.

To up engine speed and effectively increase horsepower the SRT techs modified the cams, increasing revs by 15 percent to almost 6,200 rpm - the current 5.7-liter HEMI tops out at 5,400 rpm. The engine's hollowed out valve stems also reduce drag due to their lighter weight. Interestingly, the hollows are filled with sodium for dissipating heat more effectively.

Like an athlete, an engine will perform better if it can breathe easier. To achieve this result SRT engineers added new high-flow cylinder heads, with larger diameter

The SRT techs modified the cams, increasing revs by 15 percent to almost 6,200 rpm. (Photo: Trevor Hofmann, Canadian Auto Press)

valves combined with reshaped cylinder ports, and a redesigned intake manifold with larger diameter runners for higher-speed tuning. The result of the SRT division's work is a quicker turning, much more powerful engine featuring a compression ratio that increases from 9.6:1 to 10.3:1.

Finally, exhaust headers were fitted that feature "individual tubes encased in a stainless steel shell", or so says Chrysler. Engine exhaust will leave the back of the car via new larger diameter 2.75-inch pipes, compared to the stock 2.5-inch tailpipes, finished off with two fat 3.5-inch chrome tips.