Someone In Sweden Owns A GM Duramax 4.5L V8 LMK Engine

Shortly after the 2008 financial crisis and the Great Recession that followed, GM canceled its 4.5L V8 LMK turbodiesel Duramax engine. Originally destined for the engine bays of GM’s 2010-model-year light-duty pickup trucks, the 4.5L V8 LMK never made it to full production. However, a handful of prototypes did eventually find their way into private hands, and now, this ambitious diesel-powered V8 has reemerged in a somewhat unexpected place – a private garage in Sweden.

According to a recent report from The Drive, the LMK Duramax is once again making its way into the limelight thanks to Swedish enthusiast Henrik Bengtsson, who unexpectedly acquired the rare powerplant while buying a turbocharger through an online marketplace. The seller apparently had ties to a firm involved in GM powertrain certification for use in marine applications, and Bengtsson ended up with one of the few surviving examples of the engine that never was.

The 4.5L Duramax LMK features a good deal of innovation, including a hot-vee turbo configuration wherein the turbocharger is placed between the cylinder banks for improved responsiveness and efficiency, along with a high-pressure fuel injection system and advanced emissions technology. Diesel performance legend Gale Banks, who consulted on the project, notes that the LMK was a victim of circumstance, rather than an example of poor engineering.

Though the LMK never entered production, its influence is evident in later GM powerplants, including its 3.0L Duramax inline-six, the latest iteration of which (LZ0) can be found in GM’s light-duty pickups, as well as its full-size SUVs. Interestingly, former GM brass Bob Lutz once put an LMK under the hood of a Buick Rainier, and even tested it at the Milford Proving Ground.

Only a handful of LMK engines were built, and most are believed to have been destroyed. It remains unclear how Bengtsson’s example made it overseas, but its survival offers a rare glimpse into an alternative direction GM once considered for its truck powertrain strategy.