Heavy Breathing

General Motors got the diesel-truck-enthusiast world’s attention in June when it revealed the face of the 2017 GMC Sierra Denali 2500 HD and its prominent hood scoop. That press release was vague to its function other than to say it “hints what lies beneath” It doesn’t take a rocket scientist to deduce that an updated 6.6L Duramax V-8 diesel engine is what lies beneath.

The scoop is part of a dual-circuit cold-air intake system.  The purpose of the scoop is to draw 60 percent of the intake air in, resulting in a lower air intake temperature that’s closer to ambient. Without under-hood photos to reveal the system’s shape, we must rely on the description. The scoop is described as going into a 180-degree elbow with a water-separator function to ensure the air going into the engine is cool and dry. The rest of the intake charge is drawn through an intake snorkel mounted in the front fender.

Extensive testing was reportedly conducted on the system in both real-world and lab simulation conditions to ensure proper operation regardless of conditions. Details and output figures on the next-generation Duramax are due closer to the trucks on sale date, expected in fourth quarter 2016.

What we’re reading into that is this is going to be one beastly diesel. The current high-water mark for hp in the class is the Ford 6.7L Scorpion Power Stroke with 440hp, and the bar for torque stands at a thundering 900lb-ft for the 6.7L Cummins I-6 in the Ram 3500. With those numbers in mind, we’re expecting the new 6.6L Duramax to easily top 400hp and 800lb-ft of torque.  Also unknown is what the all-important regular production order (RPO) code will be for the new engine. There is not an exact sequence to it. The Duramax, over its five generations, has gone from LB7, LLY, LBZ, and LMM to LML. Regardless, we’re confident it will be the most-powerful, most-refined, and most-capable Duramax to-date. We can’t wait to get more info on the General’s new diesel beast!

BY EDWARD A. SANCHEZ

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