Nouveau V6 3900: une première push road avec VVT.
Pour être simpliste système VTEC dans un push road (OHV)
The large displacement of the 3900 V-6 – achieved with 99-mm offset bores and an 84-mm stroke – combines with torque-enhancing technologies such as active air intake to produce a broad, flat torque curve that translates into exceptional all-around performance and terrific off-the-line launch feel. With active air intake, air entering the engine is continuously tuned through a valve in the intake manifold to deliver optimized low-, mid-range and high-rpm torque. In fact, 90 percent of peak torque is available from 1800 to 5800 rpm.
Variable valve timing is used to bolster performance, enhance economy and reduce emissions. An electronically controlled cam phaser provides for infinitely variable adjustment of camshaft timing in relation to the crankshaft. By electronically controlling the camshaft, the optimum location can be selected for various engine operating conditions, maximizing torque and horsepower outputs. The 3.9L V-6 is the first production cam-in-block engine to incorporate cam phasing.
Yeah, that's right. Variable-valve-timing. Cam Phasing. In an OHV 6-cylinder engine. A rare engine indeed. And given GM's push for hydrogen powered cars, who knows - this just might be (to coin a heavily modified phrase from The Road Warrior) "The Last of the Great Pushrod V6's". But all hydrogen speculation aside, it really is a neat and unique piece of technology. It straddles the line between GM's "Value" 3500 V6, and "High Feature" 3.6L DOHC engines, and it brings a little of both worlds to the table. Cost efficiency, fuel economy, and good performance. In fact, its horsepower rating goes toe to toe with the legendary Series II Supercharged 3800 V6 - which is still being used in the 2005 Monte Carlo SS Supercharged.
Some in the media will no doubt try to trash the engine based on its "ancient pushrod design". But they'll have a hard time convincing people when it has the same sort of technological advancements (like VVT) as the LS2. The 3900 isn't merely a bored out 3500. It's tuned for performance, and it should show. Sure, you could probably find an Import coupe with a V6 that gets better "horsepower per liter" (which doesn't necessarily mean the overall package/size of the competitors engine is "smaller"), but look at it from a total package perspective when it comes out, including price, and see if it still falls short. After all, Pontiac is supposed to be about Performance on a Budget.
