General Motors has announced that it's investing more than $890 million to build its next-generation small-block truck and car engines. The engines are expected to appear in the redesigned Chevrolet Silverado and GMC Sierra when they debut around 2013.
According to GM's news release, "the next generation small block engine family will have unprecedented fuel efficiency through direct injection and an all-new advanced combustion system design. The new engine family will rely exclusively on aluminum engine blocks, which are lighter and contribute to the improved fuel efficiency. In addition to being E85 ethanol capable, these engines are being designed with the capability to meet increasingly stringent criteria emissions standards expected throughout this decade."
GM's coy reference to "an all-new advanced combustion system" may indicate that we'll see an all-new approach to variable valve timing in an overhead valve (pushrod) engine that would allow cam phasing of both the intake and exhaust valves, like a dual overhead cam V-8. In GM's current 5.3-liter small-block OHV V-8, cam phasing is limited to just the intake valves because of its cam-in-block architecture. The new method could use so-called "cam-in-cam" timing.
"These will be V-8 engines," a GM spokesperson said. "They'll use aluminum across the board. That's all we can say for now."
In 2007, before GM scrapped its original plans for its next-generation full-size pickups that were being developed under the code name C3XX, word leaked from United Auto Workers sources that a new “Gen V” overhead valve V-8 was going to replace the current 315-horsepower, 335 pounds-feet of torque 5.3-liter V-8. The final displacement wasn’t determined yet because it was referred to as 5X.
The new engine plans would create or retain more than 1,600 jobs at five North American plants.
http://news.pickuptrucks.com/2010/04/gm-announces-big-investment-in-nextgen-small-block-v8-engines.html