4-Cyl Duramax Raises Performance to New Levels
GM’s next-generation turbo-diesel leads class in power and torque; 2nd-generation world diesel sets new standards
by Bruce W. Smith
If you want to see the future of U.S. diesel pickup engines, keep a close eye on what’s happening 8,500 miles west of Detroit. Or for that matter, anywhere else but on the North American continent.
We love our high-horsepower, V-8 gas and diesels and big pickups here in the U.S.
But the rest of the world is quite happy driving V-6 and 4-cylinder diesels in mid-size trucks.
That’s why GM, among others, has invested a lot of time and money engineering some of the best little diesels on the planet and doing so on the other side of the world.
Case in point: The 2nd generation 163hp 2.5L and 200hp 2.8L Duramax (MY14) four-bangers just introduced in Bangkok, Thailand.
(GMs Thailand marketing numbers show the first generation in a 4×4 Colorado fuel economy at 25.57 mpg–and the new version is 6% better.)
Both engines will be showing up in the Thailand and Southeast Asian Colorado pickup truck and Trailblazer SUV, two of Chevrolet’s most popular overseas models.
“When we launched the first generation Duramax four-cylinder turbo-diesel engines two years ago, both the 2.5-liter and 2.8-liter variants delivered best in class power and torque outputs,” said Nicola Menarini, Global Chief Engineer, GM Powertrain.
“The new-generation, MY14 Duramax engines just raised that bar even further with unprecedented levels of output from a compact and highly-efficient construction. When we were developing the second-generation Duramax engine, outright power and torque outputs were not the main priorities,” Menarini said.
The 2.8L has several new parts, namely a new water-cooled variable-geometry turbocharger, a new high-pressure common-rail fuel delivery system, a new Exhaust Gas Recirculation (EGR) system, a new intake manifold, a new cylinder head, a new cylinder block, a new balancer shaft unit and a new Engine Control Module (ECM).
The 2nd Gen Duramax fours are also very clean: GM says both engines are Euro-4 compliant and can be upgraded to meet Euro-5, -6 and U.S. emission standards if necessary.
The new Duramax engines were engineered in Europe and the U.S., with global application as one of its developmental objectives. They are being built in the $200 million GM Powertrain Thailand plant, which is their most advanced diesel engine facility.
Will these new diesels see the light of day in the States? You can count on it.
Duramax 2.5L/2.8L Key Components;
- Commonrail system – The high pressure fuel pump of the second generation Duramax engine operates at pressures up to 2,000 bar, enabling increased engine efficiency. It provides a high pressure fuel in the common rail system and a fine vapor is sprayed into the engine based on input from the ECMto ensure efficient combustion and performance while reducing CO2 and fuel consumption.
- Turbo (2.8L) – The improved variable-geometry turbo incorporates a water-cooling system in the turbine housing to reduce heat when operating at high speeds and full load. This feature extends the life of the turbo and the engine
- EGR valve and EGR cooler – The new EGR system Decreases exhaust emissions (oxides of nitrogen / NOx) by reducing charge temperature and reducing excess levels of O2 in the combustion chamber. The new Duramax engine uses an Electric EGR valve for greater precision and a larger EGR cooler to further reduce recirculated exhaust gas temperature.
- Intake manifold – The new engine uses an enhanced, lighter and higher efficiency intake manifold, which helps improve overall engine performance. The redesigned and improved intake manifold allows increased exhaust gas recirculation and increases air intake efficiency. In conjunction with the new EGR system emissions are reduced.
- Cylinder Head – An improved and redesigned cylinder head has a larger exhaust port and water passage to enhance cooling efficiency. The new engine comes with an improved oil distribution channel to enhance lubricant supply in the cylinder head. The second generation cylinder head is lighter and increases overall engine efficiency.
- Cylinder block – New water jacket and cooling circuit design in the new cylinder block helps improve heat exchange. The new cylinder block is also lighter, , which contributes to improved vehicle efficiency
- Balance shaft unit – Reduces vibration and noise caused by crankshaft and reciprocating parts. Redesigned components inside the balancer shaft and an improved production process reduces engine vibration and noise.
- Engine control module (ECM)- New software and hardware was developed by the GM engineering team for quicker response, improved accuracy and precision of overall engine control. The second generation engine offers better fuel economy, performance and lower emissions.