Posted: 08/17/09 05:26 PM
In a radical departure from the current 5.4L Triton V8 engine, the upcoming optional 6.2L V8 that will be offered as an option in the Raptor off-road package on the F-150 will have a big-bore, short-stroke design, with two valves per cylinder (compared to the current 3-valve design on the 5.4), and twin spark plugs. The bore & stroke of the 6.2 are 102 mm and 95 mm, respectively, compared to the current 5.4's radically under-square (long stroke) 90.2 mm x 105.8 mm.
Although some enthusiasts were initially disappointed to hear that the 6.2 would "only" be a 2-valve engine, the much larger bore dimensions will likely yield a greater overall valve surface area and CFM potential than the 5.4's somewhat choked airflow. Although estimated torque output of the 6.2 is only about 35 lb./ft. greater than the current 5.4's 365, it will have a substantial improvement of 90 horsepower to the 5.4. Even though the 6.2 is overhead-cam, it seems Ford likely benchmarked the GM LS3 and L94 6.2L V8s, which coincidentally have a 103.25 mm bore and 92 mm stroke. The Ford's stated power peak of 5,500 rpm is also 500 rpm higher than the 5.4, making the engine better-suited to the high-speed off-road driving for which the Raptor is designed.