Long-Block And Fuel-Injection SystemKatech's billet-aluminum block is made of 6061-T61 aluminum and, not surprisingly, requires many hours to carve. When that procedure is completed, along with the typical finish machining required of all cylinder blocks, the bores measure 4.205 inches. They're complemented by a 4.500-inch-stroke crankshaft, along with K1 H-beam rods and Katech's own aluminum pistons. The parts work together, drawing air into and pushing it out of the combustion chambers of a set of GM LS7 cylinder heads. They're used as-cast, with only upgraded springs and retainers to separate them from the heads on a factory-built Z06.
When it came to the camshaft, Henderson's aforementioned desire for good driving manners yielded a custom grind with 0.683/0.694-inch lift specs, 235/249-degree duration, and a comparatively wide 114-degree lobe-separation angle (although it's still narrower than the standard 120-degree angle of the standard Street Attack 500 profile). So, while the cylinder block is decidedly exotic, the long-block assembly is a straightforward collection of off-the-shelf components. And truth be known, the Kinsler injection setup isn't all that exotic in its operation--it just looks the part (and costs it, too).
The basic design of the system is not unlike that of the factory sequential-port system, but rather than a single throttle body and plenum-style manifold serving as the gateway to the combustion chambers, the Kinsler setup uses individual runners equipped with their own throttle blades. Peak power in the rpm band is adjustable via the length of the air tubes--shorter tubes make power at higher rpm, while longer tubes deliver more bottom-end.
"The tube length of this project engine was selected to deliver power where it would be more usable on the street," says Harding. "It also makes great torque."
Strong torque is an added benefit of the cross-ram system, according to Kinsler's Greg Murchison.
"The cross-ram design enables longer tube length without the worry of hood-clearance problems, so the torque is amazing," he says.
Now, before you rush out to pull off the factory intake on your C5 or C6, know that the Kinsler isn't for everyone. It requires cable-operated throttle control and can interfere with all sorts of factory accessories on an otherwise stock vehicle. And like Katech's aluminum block, a made-to-order Kinsler system isn't exactly what you'd call a "budget" item. Still, that cross-ram styling and those carbon-fiber air horns beat the hell out of a factory-style black-plastic intake manifold any day of the week.
Tuning And Driving DetailsKatech used a GM MEFI-4B engine controller to tune and manage engine operation on the dyno. The Kinsler injection system didn't require unique tuning, but unlike the latest LS engines, it uses a conventional cable-operated throttle rather than an electronically controlled one. That's just fine for Henderson's '67 Vette, since the car didn't require the pedal mods associated with converting to an electronic throttle.
Considering its street-driven intention and the fact that no manner of forced induction is used, that 701hp figure seems even more impressive. Only few years ago, such an achievement was almost unthinkable, but big leaps in engine management and the seemingly boundless capability of the LS engine platform is bringing race car-level performance to daily-drivable street cars.
The engine will paired with an RPM-built Tremec T56 six-speed, including paddle-shift control. That engine/transmission combo will rest in a C4-suspensioned tube chassis from Jameson's Custom Corvette. The car will be painted the Atomic Orange and black, and fitted with an ostrich-skin interior. We're planning a follow-up on the project, so stay tuned.
We don't yet know if Joe Henderson plans to commute around Ashville in his Katech/Kinsler-powered '67 Corvette, but with all that modern equipment beneath those classic lines, it would be seem impossible to resist.