Cadillac twin-turbo V8
|Cadillac Blackwing V8|
|Also called||LTA |
|Displacement||4.2 L; 255.8 cu in (4,192 cc)|
|Cylinder bore||86 mm (3.39 in)|
|Piston stroke||90.2 mm (3.55 in)|
|Valvetrain||DOHC 4 valves x cyl.|
|Turbocharger||hot-V twin scroll Twin-turbos with intercoolers|
|Fuel system||Direct injection|
|Power output||500–550 hp (373–410 kW)|
|Specific power||131.2 hp (97.8 kW) per liter|
|Torque output||574–640 lb⋅ft (778–868 N⋅m)|
|Predecessor||Cadillac Northstar engine|
The Cadillac Blackwing V8 (GM RPO LTA) is a twin-turbo DOHC V8 engine produced by General Motors for use in Cadillac vehicles only. It is a clean sheet engine design, as well as Cadillac's first ever twin-turbo V8 engine. The engine was branded as the "Blackwing V8" by GM technicians, and is the first Cadillac-exclusive dual overhead cam V8 engine since the Northstar V8 was dropped in 2011.
The aluminum cylinder block features pressed-in iron liners, cross-bolted main bearing caps and houses a lightweight rotating assembly composed of a forged steel crankshaft, forged steel connecting rods and high strength hypereutectic aluminum pistons. Its firing order is 1-5-4-3-6-8-7-2.
The aluminum cylinder heads house dual overhead camshafts and four valves per cylinder; exhaust valves are sodium-filled.
The turbochargers are mounted between the cylinder banks in a so-called hot-V configuration and their twin scroll design broadens their performance capability, offering quicker response and greater efficiency. The turbochargers produce up to 20 psi (1.4 bar) and are matched with electronic wastegate control for more precise boost management and more responsive torque production. Ninety percent of the engine's peak torque is available at 2000 rpm and carried through 5200 rpm.
The engine features the following highlight characteristics:
- Twin-scroll turbochargers
- Electronic wastegate control
- Dual water-to-air charge coolers
- Dual electronic throttle bodies
- Direct injection
- Dual-independent camshaft phasing
- Active Fuel Management / Cylinder Deactivation
- Variable-pressure oiling system with piston-cooling oil jets
- Stop/start technology
When Cadillac introduced the new CT6-V in March 2018, the production was limited to 275 units for the US market. The entire allocations were sold out in minutes as soon as the pre-order book was opened in January 2019. Cadillac did not anticipate the strong demand and introduced the second CT6 model with detuned Blackwing engine: CT6 4.2 Platinum, which sold out quickly as well.
Cadillac intended for the Blackwing V8 engine to be exclusive for its flagship sedan, CT6, and stillborn larger sedan, Escala. However, the CT6 has been a poor seller during its entire model run and was cancelled on February 2020 (at the beginning of the emerging Covid-19 pandemic). With estimated production cost of $20,000 per engine, the Blackwing V8 would be too expensive for Escalade given the fact that each engine was built by one specialist builder. The Blackwing V8 engine without twin turbochargers would produce similar performance as cheaper 3.0-litre twin turbocharged LGW V6 engine.
|2019||Cadillac CT6 4.2 Platinum||500 hp (373 kW) @ 5,700 rpm||574 lb⋅ft (778 N⋅m) @ 3,200-4,000 rpm|
|Cadillac CT6-V||550 hp (410 kW) @ 5,700 rpm||640 lb⋅ft (868 N⋅m) @ 3,200-4,000 rpm|
- Brzozowski, Aaron (20 September 2018). "What's A Northstar? New Twin-Turbo Cadillac V8 Named 'Blackwing'". GM Authority.
- Luft, Alex (23 January 2019). "2019 Cadillac CT6-V Preorders Sell Out Within Minutes". Cadillac Society.
- Traugott, Jay (21 February 2019). "Missed Out On A 550-HP CT6-V? Cadillac Has A Solution". Car Buzz.
- Perkins, Chris (16 June 2020). "Why Cadillac Killed Its Landmark Blackwing V-8 Engine". Road & Track.