DETROIT, Michigan — In its latest effort to match luxury street cred with Mercedes-Benz, BMW, and Audi, Cadillac has unveiled a “clean-sheet design,” exclusive, 500- to 550-plus horsepower hand-built 4.2-liter twin-turbo DOHC V-8 engine to be available in the CT6 early in 2019. The new Cadillac V-8, which doesn’t yet have its own brand name, will be hand-built in General Motors’ Bowling Green, Kentucky, Performance Build Center, home of Chevrolet Corvette production.
The engine also will be General Motors’ first to apply Active Fuel Management cylinder shutoff to an overhead cam engine. Preliminary numbers are 550 hp @ 5,700 rpm in high-output form, and 500 hp @ 5,000 to 5,200 in “standard” form.
In both standard and high-output form, the V-8 is a “hot V” design, with its turbochargers and exhaust system, including catalysts, in the engine’s 90-degree valley. Torque is an estimated 553 pound-feet at 2,600 to 4,600 rpm with the standard engine. Preliminary numbers for the high-output version are 627 pound-feet at 3,200-4,000 rpm, with 90-percent, or about 564 pound-feet, available between 2,000 and 5,000 rpm.
The longitudinal-mounted engine has been designed for all-wheel-drive, with an axle through-tunnel in the oil pan, though Cadillac engineers said it could be adapted for rear-wheel-drive, and said it could potentially get more power for other applications—if it built a CT6-V for example. But engineers presenting the new engine would not comment on any future product, of course.
“This engine has the character of a V-8,” which feels much different, smoother and more refined with a different exhaust note than GM’s twin-turbo 3.6-liter V-6 in the Cadillac ATS-V, said Jordan Lee, Cadillac V-8 chief engineer. That TT V-6 is rated 464 hp and 453 lb-ft. in the ATS-V, which means it would not be that hard to push those numbers closer to the new V-8’s.
Cadillac officials insist the new V-8 will be exclusive to the luxury brand, though there have been rumors it will be shared with the next-generation, C8 Corvette.
The high-output version of the Cadillac V-8 will launch early next year in the new 2019 CT6 VSport, which gets a facelift that amps up the brand’s Escala concept design language. The VSport trim also adds a mechanical limited-slip rear differential, specific (stiffer) suspension tuning, exclusive 19-inch Brembo brake system, modified steering and Magnetic Ride Control damper settings, active valve exhaust system with “more sound character,” and summer tires developed exclusively for the car.
The non VSport CT6 will be offered early next year with the 500-horsepower version of the Cadillac V-8, expanding that car’s engine lineup to five powertrain choices.
In addition to the twin-turbo 4.2L V-8, Cadillac already offers the CT6 with a 2.0-liter turbo I-4, 2.0-liter turbo I-4 plug-in hybrid, 3.6-liter V-6, and 3.0-liter twin-turbo V-6. It seems likely at least one of those engine choices might be dropped with the addition of the Cadillac V-8.
The new V-8 has an 86 mm bore and 90.2 mm stroke, and a 96 mm bore-spacing. With the “hot V” design, exhaust ports flow into the valley side of the engine, and the integrated exhaust manifold has dual-compact high-output twin-scroll, titanium-alumide turbine wheel turbochargers, which spin up to 170,000 rpm. Maximum boost is 20 psi.
The engine is tight, compact, and complex. It comes with lifetime spark plugs; a good thing, considering the minimal clearance for their replacement.
The only transmission available with either version of the engine is GM’s 10-speed Hydra-Matic automatic transmission. It has a wide, 7.39 overall gear ratio spread, for smaller steps between the gears.
Like traditional Mercedes-AMG engines, the new Cadillac V-8 will be hand-built, with one builder per engine, and his or her name inscribed on a special engine plate.
So that’s as exhaustive as we can get, reasonably, with the new V-8’s engine specs. Why is Cadillac adding this complex, expensive engine now?
A replacement for the old Northstar V-8 has been an on-off proposition at GM since before its 2009 bankruptcy. An earlier program was put on ice after the bankruptcy, and we’ve heard it’s had starts and stops since the industry began its recovery in 2010-11. Like typical engine programs, this one began three or four years ago, chief engineer Jordan Lee said, but don’t believe anyone who tells you that Cadillac President Johan de Nysschen, who joined the company from Infiniti in August 2014, was the impetus for it, even though he most certainly has been in favor of it.
Could Cadillac ever raise itself to Mercedes-Benz and BMW level-prestige by relying on the Chevrolet OHV small block V-8, now a 63-year-old design? True, V-8s are disappearing from mainstream cars, but that’s the point: if your business remains defined by big, flagship sedans, you’re going to offer a V-8 for at least another decade, even if it’s a small-volume option.
So that’s what Cadillac will have early in 2019. For now, the Cadillac CT6 seems too low-volume a car to make the V-8 pencil out for the division, which has been its own business unit within GM for about three years. Cadillac sold 10,542 CT6es last year. If the V-8 take-rate is 10-percent, a reasonable guess, that’s just 1,000 engines per year.
But Cadillac sold 37,694 Escalade/ESVs last year, all of them V-8s. Replacing the Small Block with the Cadillac V-8 would be a good way to delineate the Escalade line from GMC Denalis, but that’s too big a number for an expensive, hand-built V-8. We’d put our money on the new Escalade, arriving by 2020, offering the new Cadillac engine as a high-cost option, or on just the top trim level of the SUV.