Engine – Callaway C16
A Very Special Engine
The Callaway C16 is powered by a very special engine. Each is machined, assembled and dyno-tested in Callaway’s state-of-the-art engine shop by expert craftsmen. No off-the-shelf “tuner” parts here, this engine specification has been developed by Callaway engineers applying the company’s established high power – perfect drivability – extended durability philosophy.
Positive Displacement Legacy - Callaway’s engine development history is steeped in positive displacement applications. The BMW, VW and Porsche aftermarket turbocharger kits built by Callaway in the 1970′s, the Alfa Romeo GTV6 and Callaway Corvette original equipment turbocharger systems produced in the 1980′s and 1990′s, and the MazdaSpeed Protegé original equipment turbocharger systems manufactured in the 2000′s are just a few of the turbo-supercharging projects developed by Callaway. Consequently, when deciding on how to power the Callaway C16, supercharging the LS-series Chevrolet V8 was the obvious path. The service-proven, Eaton based supercharger design provides reliable, predictable increased manifold pressure while eliminating the complexities of turbochargers, including external lubrication and cooling, and requiring components that can endure the high rotational speeds and broad temperature excursions of exhaust-driven turbo-supercharging.
The Heart of the C16 – To produce 650+ horsepower with a LS-series Chevrolet engine, manifold pressure is set higher than Callaway Corvette, Camaro and SportTruck superchargers. To accommodate the increased stresses, engine components are upgraded and tolerances are tightened. The C16 engine’s cylinder bores are honed in Callaway’s state-of-the-art engine shop to precise concentricity, surface finish and piston-to-wall clearance specifications. High strength forged pistons, built for Callaway by Mahle, replace GM’s cast pistons. Callaway-proprietary piston rings are file-fit for accurate end gap and perfect sealing. Oliver forged connecting rods replace the LS3′s powdered metal rods, and are longer than stock for improved combustion and more power. Pistons, rods and crankshaft are balanced to tenths of a gram with Callaway’s computer-controlled Hines balancing equipment. Callaway’s proprietary camshaft profile is specifically designed for this supercharged application, with abundant mid-range torque and excellent high RPM power, without the radical idle and poor low-end response of other “high-performance” cams. A high volume oil pump ensures proper lubrication under the most severe conditions.
Selected GM cylinder head castings are ported by simultaneous 5-axis computer-controlled machining centers to provide identical port-to-port flow characteristics, with port design configured and flowbench tested for maximum flow by Callaway engineers. Combustion chambers are also CNC-machined to recontour chamber shape for improved flame travel and heads are milled to establish specific chamber volume and compression ratio. Callaway-proprietary, large diameter, severe-service stainless steel valves are installed to contribute to increased flow rate. Valve seats are radius-machined with special tooling on Callaway’s extremely accurate, French-built Serdi cylinder head machine. Callaway-proprietary valve spring design is a result of our experience with LS-series valve spring development conducted for Callaway-built Holden Monaro LS1 engines. They eliminate valve float and spring breakage at high RPM while avoiding excessive spring pressures that can sap power and reduce service life. A high volume oil pump ensures proper lubrication under the most severe conditions.
Having Your Cake and Eaton It Too - To provide increased manifold pressure, Callaway engineers selected the Eaton TVS2300 (Twin Vortices Series) supercharger. It’s no coincidence that the Corvette ZR1, Cadillac CTS-V and the Camaro ZL1 use the same Eaton-manufactured supercharger internals. The Roots-style configuration provides a remarkable increase in peak power and an exceptionally broad, flat torque curve – unequalled by centrifugal or twin screw designs. The high-helix angle, four-lobe TVS rotor design provides higher efficiency than any of its predecessors while retaining bulletproof reliability. The unique air-to-liquid intercooler design, integral with the intake manifold base, significantly lowers charge air temperature to further increase power and prevent engine-damaging detonation. To reduce power-robbing parasitic drag, an internal bypass diverts the inlet air flow path during idle, low-load cruising and deceleration, allowing the supercharger internals to spin freely.
Higher Brain Activity – Callaway engineers utilize the GM sensors, actuators and powerful electronic control modules to precisely control fuel delivery, ignition timing and other functions. Experience gathered in over 25 years of electronic engine management calibration and an OEM-style system validation approach allowed them to present a highly refined control algorithm, providing spectacular power without detonation or excessive operating temperature without significant fuel mileage penalty.