Cadillac First-Ever Twin-Turbo V-8 Engine

Oh my! A Twin Turbo 4.2 V8! 

According to some of the media it sounds like it will be in the new CT6 V-sport! I wonder what the chances are of it being in the CTS down the road?

Cadillac states that “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 engineering prowess embodies the very spirt of Cadillac performance on and off the racetrack."

Damn right we could take this thing on the track! It would be a sin not to!

“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.”

Why the small motor?  Well Cadillac has the theory of small displacement and large effect. How?  They state"  "The new Cadillac Twin Turbo V-8’s foundation is an all-new, durable and lightweight aluminum cylinder block that houses an equally robust, lightweight rotating assembly composed of a forged steel crankshaft, forged steel connecting rods and high-strength aluminum pistons.

The crankshaft’s 90.2mm (3.55 inch) stroke complements the cylinder bores’ 86mm (3.39 inch) diameter to give the engine its 4.2L (255 cubic-inch) displacement.

Its comparatively small bore dimension enables the reduction in the size and weight of the pistons, optimizing the engine’s geometry to match the fast-rev capability permitted by the engine’s low-inertia, twin-scroll turbochargers. The result is exceptional responsiveness and immediacy of power across the rpm band.  

The turbochargers produce up to 20 pounds of boost (1.38 bar) and are matched with electronic wastegate control for more precise boost management and more responsive torque production. In fact, 90 percent of the engine’s peak torque is available at only 2000 rpm, and it is carried through 5200 rpm for a confident, virtually bottomless power reserve."

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

Did they just say Twin Throttle bodies!!? When I think of twin Throttle bodies I always think of this manifold. 

Given it will look nothing like that but I am sure after you take off those hideous engine covers I am sure you will be able to see some great engineering.

What are your thoughts about the Active Fuel Management?  I am not a big fan on AFM but I totally understand by the way the government is demanding better fuel efficiency form car manufacturers. 

and here are your specs!


4.2L twin-turbocharged DOHC V-8 with Active Fuel Management, direct injection and stop/start

Bore and stroke       (in / mm):

3.39 x 3.55 / 86 x 90.2

Block configuration:

90-degree V-8 with five cross-bolted nodular iron main bearing caps; with provisions for jet-spray oil cooling

Block material:

A319 sand-cast aluminum with pressed-in iron liners


Forged steel


High-strength hypereutectic aluminum with friction-reducing polymer skirt coating

Connecting rods:

Forged steel with floating wrist pins

Cylinder heads:

Cast aluminum “hot V”-type with 36mm intake valves and 29mm sodium-filled exhaust valves

Compression ratio:



Dual overhead camshafts; four valves per cylinder with and dual independent valve timing

Firing order:

1-5-4-3-6-8-7-2 (1-4-6-7 with Active Fuel Management engaged)

Ignition system:


Fuel delivery:

Direct injection with dual electronically controlled 59mm throttle bodies

Turbocharging system:

Two low-inertia twin-scroll turbochargers with electronically controlled wastegates and water-to-air intercooling

Max boost:

20 psi (1.38 bar / 138 kPa)

Horsepower             (hp / kW @ rpm):

550 / 410 @ 5700 (CT6 V-Sport) – est.

500 / 373 @ 5000-5200 (CT6) – est.

(lb.-ft. / Nm):

627 / 850 @ 3200-4000 (CT6 V-Sport) – est.

553 / 750 @ 2600-4600 (CT6) – est.


So what are your thoughts on this twin turbo monster? and can we ask GM.... can we get a crate motor for a swap! :P

CadillacTwin turbo

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