Just a few short weeks ago, Chevrolet announced the all-new, advanced 3.0-liter Duramax Turbo Diesel engine for the 2020 Silverados. Although they were supposed to launch this year, it was pushed. But, it’s confirmed. These light trucks have been getting more and more attention and now, they definitely have our attention. The 3.0-liter is an inline-six configuration and it adds another tough option when you’re headed to the dealer for a new rig.
Accommodated with the V8 configuration, Chevrolet engineers have started with a clean slate and have developed this new engine that redefines efficiency with a new architecture of the inline six. If you’re looking for a new Silverado, you still have your other choices of powerplants, but the 3.0-liter comes at a competitive price.
“From the moment the engine is started to its idle, acceleration and highway cruising, the 3.0-liter Duramax performance will change perceptions of what a diesel engine can offer in refinement,” said Nicola Menarini, director for Diesel Truck Engine Program Execution. “With advanced technologies that draw on global diesel expertise, it’s a no-compromise choice for those who want the capability and driving range of a diesel in a light-duty truck.”
This engine comes in many different of your favorite truck packages such as the LT, RST, LTZ and High Country models. Coming into this world, this 3.0-liter engine is rated at an SAE-certified 277 horsepower and 460 lb-ft of torque. With those numbers, it delivers most of its torque at only 1,250 RPM. Peak torque is sustained from 1,500 RPM through 3,000 RPM which provides a smooth, yet powerful, driving experience.
Active Thermal Management is designed to help the engine warm up quickly to achieve and maintain its optimal temperature for performance and efficiency over the entire operating range. The system uses a three-actuator rotary valve system that distributes coolant through the engine in targeting the areas in need. In short, it sends heat where it needs it the most to warm up the engine to reduce friction and heat or cool the passenger cabin when needed.
The 3.0-liter Duramax cylinder block is made of a cast aluminum alloy that offers the strength and integrity required to support high-combustion pressure a diesel engine creates. All this while supplying approximately 25-percent mass savings compared to the traditional cast iron block. To ensure the longevity of this engine, it has been developed with iron cylinder liners which will guarantee durability.
The rotating assembly contains forged steel connecting rods, a forged steel crankshaft, and hypereutectic aluminum pistons. A hypereutectic piston is made of an aluminum alloy which has more silicon present than normal. With the additional silicon, it changes the aluminum’s properties in a way that is useful for these high combustion engines. With the high combustion, a thick piston crown has been designed to reinforce the strength of these pistons to handle it’s high 15.0:1 compression ratio.
DOHC Cylinder Head and Rear Cam Drive
“Overhead camshafts offer a direct, efficient means of operating the valves, while four valves per cylinder activated by maintenance-free finger followers with hydraulic lash adjusters increase airflow in and out of the engine,” saidMenarini. “This arrangement is integrated on the Duramax 3.0L’s lightweight aluminum cylinder head, which is topped with a lightweight composite cam cover that incorporates the crankcase ventilation and oil separation systems.”
Menarini continued, “A pair of lightweight, assembled camshafts actuates 28.35 mm diameter (1.12-inch) intake and 24.55 mm diameter (0.97-inch) exhaust valves. The camshaft drivetrain is uniquely located at the rear (flywheel side) of the engine, for greater refinement and packaging considerations for the comparatively long inline-six. A crankshaft-driven chain drives the high-pressure direct-injection fuel pump, while a chain driven by the fuel pump drives both intake and exhaust camshafts. A smaller belt drives the variable flow oil pump from the crankshaft.”
Like most late-model engines, the turbochargers are liquid cooled and feature a low-friction, ball-bearing shaft and is mounted close to the exhaust outlet of the engine for faster spool-up times. A water to air intercooling system produces a cooler, higher density air charge for optimal power. Maximum boost pressure on these units is 43.5-PSI.
To lower combustion temperatures and rates, the 3.0-liter utilizes a low-pressure Exhaust Gas Recirculation system that diverts engine-out exhaust gas, mixes it back into the fresh air stream, and fed into the cylinder head for combustion. On the traditional diesel application, the exhaust gases are pushed through the two high-pressure points, the exhaust manifold, and intake manifold, but that requires assistance from the turbocharger which lowers efficiency.
The variable intake manifold design offers dual air intake pathways for each cylinder like a side draft commonly seen on a Cummins engine. The intake features single electronically controlled flaps for each cylinder that can shorten or lengthen the airflow to each hole. This optimizes the airflow into the engine and improves the overall performance and responsiveness across the entire RPM band.
To ensure smooth idling and lower combustion noise, the 3.0-liter features a 36,250 PSI common rail, direct injection system. The systems pressure is generated by a belt driven, twin-piston pump that sends fuel to the solenoid activated, nine-hole injectors.
The ceramic glow plugs used in the Duramax 3.0-liter heat up more quickly and hotter than conventional metal-based glow plugs, helping the engine start and heat up more quickly in cold weather. The 3.0-liter achieves unassisted and assisted starting temperatures of -22 degrees Fahrenheit and -40 degrees Fahrenheit respectively.
Like most of the newer vehicles, these Silverados will utilize the stop/start technology. Chevrolet claims this will help optimize efficiency in city driving. The driver-selectable system shuts off the engine at stoplights, or other stop and go situations, and automatically restarts the engine with the driver takes their foot off the brake pedal.
Finally, this engine is backed by GM’s 10L80 10-speed automatic transmission. It features a centrifugal pendulum absorber torque converter that reduces traveling vibration that improves smoothness. This combination also offers exhaust braking which, as you may know, uses the diesel engine’s compression to help slow the vehicle.
Is it 2020 yet? We cannot wait to get ahold of one of these new pickup trucks and check out all of these features for ourselves. The individual intake manifolds, the big-time horsepower, and torque for a light truck, and obviously the first inline-six Duramax. What are your thoughts on this so far? Let us know in the comments below. Stay tuned to Diesel Army for a full recap on the 2020 Silverados in the future.