When you think of the words "Kinsler fuel injection," your mind probably recalls the mechanical injection setups of the 1960s and '70s--those ubiquitous isolated-runner systems with ram tubes for each cylinder. They were of the constant-flow variety and offered more-precise fuel metering and easier adjustability when compared with carburetors of the same era.
Corvette racers like John Greenwood popularized mechanical injection in road racing, where low-profile, cross-ram-type injection systems aided aerodynamics by allowing lower hood profiles. And while the increasing prevalence of big-bore throttle bodies mounted on composite intake manifolds may make the old-school FI setups seem archaic, Kinsler has remained at the forefront of technology with electronic injection systems for even the newest LS engines.
Combining the vintage cross-ram look with a modern LS foundation would make a great combination for a 21st-century, pro-touring-style midyear Vette. At least, that was Tom Coleman's thought when he suggested it to customer Joe Henderson. Coleman is the proprietor of Ashe-ville, North Carolina's The Winning Collection, a top-notch restoration facility with deep racing roots. Henderson is an Ashville-based sports-car enthusiast with Ferraris and Porsches in his stable. He brought a '67 Corvette roadster to The Winning Collection, asking for the classic body to be stretched over a more contemporary drivetrain.
"Joe wanted the car to start, run, and drive like any modern car, but do so with that classic Corvette style," says Coleman. "A carbureted big-block might have been the easy way to go, but electronic fuel injection accommodates the varying air that comes with driving in the mountains around Asheville."
Having used Katech Performance engines on other projects, Coleman turned to the Michigan-based company for the engine-building chores on Henderson's project. And such a unique engine combination wouldn't rely on just any off-the-rack LS cylinder block, either. Rather, Katech started with one of its own billet-aluminum units.
You read that correctly. Katech offers its own LS block milled out of a chunk--a big chunk--of aluminum. That doesn't make it the most economical piece on the market, but the Katech block was designed to meet the strength and durability requirements of high-horsepower engines. More importantly, it enables a larger displacement than any other production-based aluminum LS block: 500 cubic inches.
"It's got big-block displacement and power, but it weighs more than 100 pounds less than an iron cylinder block," says Coleman.
Henderson's engine starts with a 500-inch short-block, is filled with Katech's basic Street Attack 500 components--an all-forged rotating assembly, custom camshaft, and deep-breathing LS7 cylinder heads--and, to cap it all off, draws air through that trick-looking Kinsler injection system.
"The Kinsler was my idea," says Coleman. "It works great, and it looks even better for a car of this caliber."
And the engine's dyno results are as impressive as the engine is eye-popping: 701 horses and 677 lb-ft of torque.
"It makes great power that's usable in all driving conditions," says Katech's Jason Harding. "It was the first 500-inch engine we built with the Kinsler system, and we were very pleased with how well it worked with our basic Street Attack 500 engine components."
Keep in mind that this engine was designed for the street, too, so the roller camshaft balances performance with good idle quality. An 11.1:1 compression ratio means fill-ups require strict adherence to premium gas, but it's definitely a pump-gas engine.
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.