2011 Chevrolet Silverado 1500 Lt Crew Cab Pickup 4-door 5.3l on 2040-cars

Auto blog

GM applies for LT5, LTX trademarks... are new small block variants coming?

Recently discovered General Motors trademark applications for LT4, LT5, LT88 and LTX have observers wondering what kind of high-performance offerings could be on their way. A new LT4 would mark a return of the engine designation first used on the Corvette Grand Sport, SLP Pontiac Firehawk and SLP Chevrolet Camaro SS from 1996 and 1997. Supposition at Corvette Forum - which provided advance intel on the C7 like these leaked images - believes a new LT4 could go into the high-performance trim of the next-gen, 2015 Camaro that would be more powerful than the 580-horsepower Camaro ZL1.
Seeing an LT5 again would also be déjà vu - in its former life it was a 5.7-liter V8 for the C4 Corvette ZR-1 from 1990-1994 designed by Lotus, producing from 370 hp to 405 hp. A mix of rumor and hope is that the new LT5 will be a supercharged evolution of the 6.2-liter LT1 (pictured) placed in the new C7 Corvette, and that it will go into the C7 version of the ZR1 pumping out something like 700 hp.
The LTX trademark is, as with that last letter, a complete mystery. If the "X" isn't a generic way to denote the whole LT family, it's wondered if it LTX could refer to a crate motor offering like the LSX.

Chevy's 6.6-liter Duramax is pretty much all new

To say there's a heated battle in heavy-duty pickups is an understatement, with Chevrolet, Ford, and Ram constantly trading blows of increased torque, horsepower, and towing capacity. The latest salvo is the revised, more powerful turbo diesel 6.6-liter Duramax V8 in the 2017 Chevy Silverado. It has 910 pound-feet of torque, an increase of 145, putting it nearly level with the Ford Super Duty. Here's a closer look at where those gains come from. How exactly did Chevrolet add all that torque plus 48 horsepower? The automaker essentially took a fine-tooth comb to the entire engine. Chevy says it changed 90 percent of the V8, and the cumulative effect of those small changes adds up to big increases. As you might guess, the turbocharger is updated. The larger unit features electric actuation of the variable nozzle turbine (VNT), and what Chevy calls a double axle cartridge mechanism that separates the VNT moving parts from the housing. That helps with heat performance as well, with a claim that the exhaust side of the turbo can run continuously up to 1,436 degrees Fahrenheit. Helping that cause are six exhaust gaskets made of Inconel - an nickel alloy that contains chromium and iron – and upgraded stainless steel for the exhaust manifold. Despite having the same cast iron cylinder block, albeit with some minor enhancements, the engine has new cylinder heads, pistons, piston pins, connecting rods, and crankshaft, which have all been upgraded to handle 20 percent higher cylinder pressures. Alongside the increase in pressure, Chevrolet also increased the cylinder head's structure with a honeycomb design. The pattern features high-strength aluminum with dual layer water jackets that not only improve strength, but also optimize water flow for better cooling. For 2017, the cylinder head also benefits from integrated plenum that aids the engine in getting more air under heavy loads. The cylinder head isn't the only component to get a minor update, as the pistons have a larger diameter pin for improved oil flow. The same detailed improvements has been bestowed to the humble connecting rods (second in our hearts only to the inanimate carbon rod). The new design has the bolts oriented roughly 45-degrees to the rod instead of parallel. The angle split design, as it's called allows for easier passage through the cylinder.

2016 Chevy Volt will not need premium gas

Buried in the new technical details of the 2016 Chevy Volt released yesterday was a throwaway line about a small but important change that's due to the new 1.5-liter, four-cylinder engine. The first-gen Volt has always required premium gas but the new powerplant will be happy burning plain old regular. The Volt's chief engineer, Andrew Farah, told AutoblogGreen that the change was due to today's Volt owners explaining they were not happy paying for top-shelf petroleum. "The ability to use regular unleaded was based directly on customer feedback," he said. "Since the range extender is an all-new engine, it was optimized to use regular unleaded at the outset. Using regular fuel will not have effect on vehicle acceleration or other performance factors." As Larry Nitz, GM's executive director of vehicle electrification, told AutoblogGreen yesterday, the new engine is more powerful and quieter than the outgoing 1.4-liter engine that's used in the current Volt. Fuel economy and EV range specs for the next-gen Volt are not expected until the full car is revealed at the Detroit Auto Show in January.