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Cadillac Introduces its First Twin-Turbo V-8 Engine

Norris McDonald
Written by Norris McDonald

Developed as a small-displacement V-8 in the classic vein and offering exceptional power density of 131 hp (98 kW) per litre, this new Cadillac-exclusive 4.2L Twin Turbo V-8 offers drivers an unparalleled experience behind the wheel.
Credit: Courtesy, General Motors

Sophisticated, all-new, 4.2L V-8 powers new CT6 V-Sport sports car

From General Motors

OSHAWA, Ont. – Cadillac has opened a new chapter in its high-performance legacy with the introduction of the brand’s first-ever twin-turbo V-8 engine.

It’s the centrepiece of the new CT6 V-Sport, an engaging sports sedan infused with the DNA of Cadillac’s world-renowned motorsports program.

Developed as a small-displacement V-8 in the classic vein and offering exceptional power density of 131 hp (98 kW) per litre, this new Cadillac-exclusive 4.2L Twin Turbo V-8 — GM estimated at 550 horsepower (410 kW) and 627 lb-ft of torque (850 Nm) — elevates the CT6’s performance to a new plateau and offers drivers an unparalleled experience behind the wheel.

An optional 500-horsepower version will also be available.

“Cadillac’s performance technology reaches new heights with the new and exclusive 4.2L Twin Turbo V-8,” said Cadillac President Johan de Nysschen. “The innovations that compose it embody the very spirit of Cadillac performance on and off the racetrack.”

The new Cadillac Twin Turbo V-8 is a clean-sheet design that also introduces unique design elements developed to balance performance and efficiency with compact, mass-efficient packaging.

“Designing an all-new engine was the best way to achieve the performance goals for the CT6 V-Sport,” said Jordan Lee, 4.2L TT V-8 chief engineer. “It builds on Cadillac’s well-established turbocharging know-how and forges new ground with innovative features that deliver exceptional performance and refinement.”

At the centre of the 4.2L Twin Turbo V-8 is a “hot V” configuration that transposes the conventional layout of the cylinder heads’ intake and exhaust systems to mount the turbochargers at the top of the engine — in the valley between the heads — to virtually eliminate turbo lag and reduce the engine’s overall packaging size.

In a conventional turbocharged engine, the cylinder heads receive the pressurized air charge through ports at the top of the engine and the exhaust exits through ports on the lower outside of the heads into manifolds connected to the turbochargers.

With Cadillac’s innovative hot V design, the intake-charged air enters through the lower outside of the heads and exits through the top inside — where the turbochargers are integrated with the exhaust manifolds — for quick spool-up that translates into more immediate power delivery.

The design also allows closer mounting of the catalytic converters, for efficient packaging.

Additional engine highlights include:

  • Twin-scroll turbochargers
  • Electronic wastegate control
  • Twin water-to-air charge coolers
  • Twin throttle bodies
  • Direct injection
  • Dual-independent camshaft phasing
  • Active Fuel Management (cylinder deactivation)
  • Variable-pressure oiling system
  • Stop/start technology

The new Cadillac Twin Turbo V-8 is matched with a 10-speed automatic transmission. Its wide, 7.39 overall gear ratio spread enhances off-the-line performance and contributes to reduced engine speed on the highway, which enhances refinement and efficiency.

Smaller steps between the gears also help the engine maintain the optimal speed for maximum power at almost all vehicle speeds.

Each engine will be hand-built at the Performance Build Center in Bowling Green, Ky.