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Four-Cylinder Truck Engines Tougher
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GM Uses Diesel Tricks to Make Its Four-Cylinder Truck Engines Tougher
The 2023 Chevrolet Colorado has ditched six-cylinder and diesel engines entirely, and now just uses the 2.7-liter turbo four-cylinder from the Silverado. The switch has made truck buyers skeptical—is there really a replacement for displacement, or diesel torque? Is General Motors just shipping trucks powered by gutless time bombs? Not according to the man who oversaw the engine's development. In fact, he went as far as calling it one of the toughest engines GM has ever built, and that's saying something.Get more news about truck engine,you can vist our website!
It would be hard to believe coming from anyone other than Kevin Luchansky, assistant chief powertrain engineer at GM. Speaking at the press launch of the new Colorado this week, Luchansky outlined the diesel-derived design elements and test regimen of what he calls "one of the most durable engines GM's ever made. It's really, really good."
Even with Luchansky's confidence, it's important to understand what worries truck owners about this lump. At 2,727 cc, it's second to only Ford's 2.7-liter Ecoboost V6 for the smallest full-size pickup motor, and the third-smallest among midsize trucks. It runs a relatively high compression ratio of 10:1, with boost pressures up to 27 psi. That results in double the cylinder pressures of a comparable naturally aspirated V8, like the 5.3-liter small-block this effectively replaces in the larger Silverado.
That could mean knocking issues out the wazoo, especially seeing as the 2.7L is designed to run on just 87-octane gas. But Luchansky was adamant that it will hold up to whatever you throw at it because he designed it using diesel engine tricks that help it hold up extraordinarily well in torture testing.
While the 2.7L is nominally an all-aluminum engine (keeping long-block weight down to 331 pounds), it actually has iron cylinder sleeves cast into the block during manufacturing. It's a more modern material though, so Luchansky says it won't wear in the way many older cast-iron blocks do.
Its pistons are an aluminum alloy too, with machined heads to optimize material properties, and cast-iron ring carriers to hold onto the rings at high cylinder pressures. In lieu of typical molybdenum-coated iron rings, the 2.7L uses diesel-grade steel rings with PVD coatings, reducing friction and slowing wear.