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VW Finds CO2 'Irregularites', SEMA Recap, and More | Autoblog Minute

Volkswagen's diesel emissions scandal gets a new wrinkle, US regulators hit Takata Corporation with a substantial fine, and we head to Vegas for a look at tuner paradise at the 2015 SEMA show. Autoblog Senior Editor Greg Migliore reports on this edition of Autoblog Minute Weekly Recap. Acura Chevrolet Honda Mazda Mitsubishi Toyota Autoblog Minute Videos Original Video Acura Legend

First 2015 Chevy Corvette Z06 engine blows up at just 891 miles

You've waited and watched and waited some more for the arrival of your 650-horsepower, $78,000 Chevrolet Corvette Z06. Finally, that joyous day arrives and you eagerly, but gingerly, begin to break-in the 6.2-liter supercharged V8 monster under your hood. Then 900-odd miles after delivery, your excitement grinds, quite literally, to a halt. That's what the owner of one 2015 Z06 claimed happened to him when a simple break-in drive resulted in a lunched engine. The owner, known as Lawdogg149 on Corvette Forum, says he was out breaking-in his car ahead of a January track event when it happened. "While making a pull from 35 miles per hour, I accelerated and shifted short of redline, and boom - the car began knocking. I pulled over and popped the hood. I could hear a loud knock coming from the No. 6 cylinder area along with a serious, grinding, metal-on-metal sound coming from the supercharger area," Lawdogg wrote. A subsequent trip to the dealer confirmed his concerns, with the service facility telling Lawdogg that the No. 6 valvetrain had failed. The dealer couldn't research the issue further, though, as General Motors requested the engine be returned for a more thorough evaluation. The good news for the Z06's unlucky owner, at least, is that GM will be covering the engine replacement under warranty, an expense that Corvette Forum estimates is a nearly $24,000 procedure. At this point, the two leading theories behind the engine's detonation involve a manufacturing defect – which could be why GM is so keen to tear the blown powerplant down – or a mistake on the part of Lawdogg. As Motor Authority points out, such an error could be something as simple as the Z06's owner accidentally shifting to first rather than third during his 35-mph pull. If, however, there's a deeper manufacturing problem with the Z06's engine, this might not be the only case we end up hearing about.

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.