"We made over 100 passes with the engine in our first COPO before touching anything on the motor," Judson said. "We tried different converters, shock setting, springs, etc., but other than pulling the valve covers off just to see what the hell was in there, we didn't touch anything." After a while, the cam got tweaked, the heads got a little CNC love, and the engine got tuned on the laptop. Those tweaks got the Camaro to a best of 9.34/141-mph in the quarter-mile.
While there have been some insane, heroic numbers thrown down by the supercharged combos available to COPO buyers, we're always intrigued by the racers running naturally aspirated and how they're making the big power and laying down the numbers that they are. To Judson, it's not a matter of whose name is on the engine but the engine itself. "I don't consider myself an 'LS person.' I am an 'air pump person,' but if we're putting things in context, the small-block Chevy is a six and the LS family of engines is a 10," Judson said. "Guys can run 9s on factory heads that were on a 2005 Tahoe, which is totally crazy but when we get to the square/rectangle-port stuff like the LS7...good grief. I know the aftermarket has to hate these heads because they are so, so good."
The LS7's greatness comes from those beautiful cylinder heads that sit atop the short-block and the 427 cubes of displacement it has. Chevrolet's C5R Corvette racing program served as a testbed for the concept that became the LS7 head. It finally came into production as a factory CNC-machined, rectangle-port monster with a 12-degree valve angle and huge 2.20-inch intake valves and 1.610-inch diameter exhaust valves. The valve angle was one of the biggest departures outside of the ports, as LS3 heads have a 15-degree valve angle. Factory stock LS7 heads have been shown to flow 370 cfm on the intake side. That is astronomical stuff for a factory-produced cylinder head. "The two things that are really impressive about the LS7 is that we're talking about an OEM production engine here with such capability as well as the fact that we live in a time where production engines come with a cylinder head with the potential that the LS7 has. You no longer throw factory heads in the trash if you are a hot rodder," GM's Dr. Meyer said.
But what about the situation we told you about in the opening to this story, the one about this being the last customer-built COPO engine ever? The handbuilt engine production line is being moved from where it is now in Wixom, Michigan, to the Corvette facility in Bowling Green, Kentucky. With that move comes the end of the option to build your own engine...for the time being. "They were kind of rolling up the carpet behind us," Judson said. "It is an incredible program, even for a guy like me who does this stuff for a living. To work on the engine with Linda and go through the entire process was really cool. From the level of technology that the builders have access to with their tools, specifically the 'torque wrench' that runs all of the fasteners down on the mains at the same time and does so to the perfect torque spec after it is scanned off of a sheet, to the level of analysis and testing done on the dyno after the engine is built, it was an amazing process to be a part of." The line is a pretty amazing mix of modern ultraefficient manufacturing tools and techniques, and good ol' gearhead know-how. "We think it says a lot for the whole experience if people like Linda and Judson were impressed because they quite literally do this for a living," Dr. Meyer added. Will the option to build your own COPO engine come back? The folks at GM wouldn't rule it out. Stay tuned!