Days of Future's PastIt's worth investigating why so much of our performance future is based on what the new car companies build. Since it's beyond the scope of most car crafters to build a car from scratch, the next best move is to take an existing car and improve upon it. Our grandfathers did it this way, and chances are that our grandchildren will also follow a similar path.
The small-block Chevy appeared in 1955 and instantly put the hurt on every flathead engine built before it. This became a watershed year for the performance industry, but it still took time for the Mouse motor to become a staple. It doesn't require much of a crystal ball to realize that we are already well into the next big era that will revolve around the GM Gen III engine.
The engine made its debut in the C5 Corvette in '97, followed quickly by the Camaro in '98. But what many don't realize is that GM is cranking out similar 4.8, 5.3, 5.7, and 6.0 L engines at an astounding rate. According to my pal Will Handzel (previous Hot Rod magazine alum and now the program manager at GM Performance Parts), GM built over one million of these engines in one year alone! So chalk up another dominant role for GM. Many refer to this Gen III engine family as the new small-block Chevy, but the reality is this powerplant is truly a corporate engine.
What's intriguing is the fact that we took a bone-stock LS1 production-line engine at 346ci and made 400 hp with it right out of the shipping crate. That's 1.1 hp/ci, which has always been the standard for a decent aftermarket performance engine. Now we're seeing that kind of power right out of the box. Some may refer to previous small-blocks that achieved that kind of power decades ago-such as the '70 LT-1. But also recall that the LT-1 relied on 11:1 compression and a seriously lumpy mechanical camshaft to achieve that standard. The LS1 runs up similar numbers with a painfully stock idle, excellent driveability, and gobs of potential remaining to be tapped.
We know that 450 hp is almost too easy for the LS1, and 500 is certainly within sight if you're willing to stuff in a big cam and live with the torque loss down low. All of this is attainable because of an excellent overall design, but also due to an impressive set of stock cylinder heads, compression that is less susceptible to detonation, reduced internal friction, and a host of other functional designs that contribute to increased efficiency. Let us not forget the EFI package or the powerful distributorless ignition system.
Right now, these engines are still a bit expensive, and high-performance parts are pricey compared to its first-generation Mouse motor cousin. But that same argument was also true of the original small-block back in the late '50s. Give the Gen III some time and the big performance aftermarket machine will crank up and start spitting out parts that will not only be more powerful, but attractively priced as well. In the meantime, the full-court press is on to see how much power these engines can produce. Who says the good old days are gone? When you can make 500 hp normally aspirated on pump gas with a street engine that will exhibit the manners of a stocker-you have a winner, my friends. I'll take today's Gen III 346 small-block over a '60s 396 anytime-especially if I can plumb one into a '65 Pontiac Tempest body and call it a born-again GTO!-Jeff Smith