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.
Gorgeous, isn't it? The Atomic...
Gorgeous, isn't it? The Atomic Orange-painted Kinsler intake manifold, along with the carbon-fiber ram tubes and valve covers, give the engine a great blend of form and function.
The cylinder block is Katech's...
The cylinder block is Katech's own big-bore, billet-aluminum piece. It enables a 500ci displacement that would be impossible to create with a production-based alloy block.
Here's the bottom view of...
Here's the bottom view of the block, showing its billet-steel main caps. Dart Machinery provides the initial CNC machining of the raw aluminum billet, which is made of 6061-T61 aluminum.
Katech finishes the machine...
Katech finishes the machine work by hot honing (with deck plates) the bores to 4.205 inches. Rather than conventional iron liners, the bores are coated with nickel-silicon carbide--a material that ranks just below a diamond in hardness. The result is exceptional wear resistance without the added weight of iron.
Engine assembly starts with...
Engine assembly starts with the installation of a Callies forged-steel, internally balanced crankshaft that delivers a stroke of 4.500 inches. It's fitted with a 24X reluctor wheel so it will work with a GM MEFI controller.
The other rotating parts include...
The other rotating parts include K1 forged-steel H-beam rods which are 6.365 inches in length; they're married to Katech's own 4032-forged-aluminum pistons. These deliver a relatively high (yet still pump-gas-friendly) compression ratio of about 11:1.
Much of the engine's combination...
Much of the engine's combination is derived from Katech's Street Attack 500 package, but the roller camshaft differs with profile specific to this engine project. Lift is nearly 0.700-inch, with a wide, 114-degree lobe separation angle that promotes a broader power band.
In keeping with Katech's roots,...
In keeping with Katech's roots, a bit of racing technology can be found in this high-tech method of degreeing the camshaft. All of Katech's engines--race or street--are degreed this way.
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.
Here's the assembled short-block....
Here's the assembled short-block. Look closely and you'll notice the lack of iron liners in the aluminum block. One of the additional benefits of this design is the ability to run larger bores with thick cylinder walls between them.
The heads are off-the-shelf...
The heads are off-the-shelf LS7 units, with upgraded springs and titanium retainers. They feature 270cc CNC-machined intake runners, 70cc CNC-machined combustion chambers, 2.20-inch titanium intake valves, 1.61-inch sodium-filled exhaust valves, and a 12-degree valve angle.
The CNC-milled intake runners...
The CNC-milled intake runners of the LS7 heads are visible here through the mounting flanges of the Kinsler intake manifold.
The Kinsler system features...
The Kinsler system features an aluminum manifold, but a lighter magnesium unit is available too. The length of the air-intake ram tubes helps determine where peak power occurs in the rpm band. Shorter tubes promote high-end power, while longer tubes build low-end power. While the cross-ram design looks great and fits under the hood, a taller system with vertical stacks is also offered.
This top-down view shows the...
This top-down view shows the long throttle linkages from each side of the intake. They're linked at the rear of the manifold and operated via a conventional throttle cable. The throttle blades for each cylinder are matched, so each opens at the same time and rate as the others.
As this engine was developed...
As this engine was developed for a very specific installation, it was outfitted with a custom March front drive system. The machined accessories complement the raw-aluminum look of the block and heads, and contrast nicely with the Atomic Orange intake, oil pan, and other details.
On Katech's dyno, the Kinsler-fed,...
On Katech's dyno, the Kinsler-fed, 500-inch LS engine made 701 hp and 677 lb-ft of torque. Better still, that power builds quickly and doesn't fall off until the very upper reaches of the tachometer. That's race-car power with pump-gas driveability.
Here's a final look at this...
Here's a final look at this gorgeous piece of machined art, which is destined for fitment into Joe Henderson's resto-mod '67 Corvette. By the way, those snazzy carbon-fiber valve covers aren't one-offs; they're new production parts from Katech that will fit any C5 or C6 Vette engine. Coil-relocation brackets are required, but Katech's got those too.
Here's a teaser shot of the...
Here's a teaser shot of the recipient of the Katech/Kinsler engine: Joe Henderson's Atomic Orange midyear. Look closely and you'll see the custom tube frame, onto which complete C4 front and rear suspensions will be attached. (Photo courtesy of The Winning Collection)