*mint* 1993 Chevrolet 4x4 Suburban 2500 454 101k Miles All Original on 2040-cars

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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.

Is your new-car warranty good at the race track?

We've all heard the horror stories. Your buddy knows a girl that was dating a guy whose best friend's brother once broke his brand-new, recently purchased performance car while making runs at a drag strip or laps at a track day, and the manufacturer wouldn't cover the repair under warranty. True story? Urban legend? Complete crap? Yes, no, maybe. One thing's for sure: Automotive warranties have always come with caveats. In 1908, an ad in the Trenton Evening Times clearly stated: "All Ford Cars Guaranteed for One Year." Although it changed over time, by 1925 the Ford New Car Guarantee only covered 90 days on material and 30 days on labor, and it clearly stated that that there was "No guarantee whatever on Fan Belts, Glass, Bulbs, Wiring, Transmission, Bands, Hose Connections, Commutator Shells, Rollers, Spark Plugs or Gaskets." Whether or not Ol' Henry would pay to fix your Model T if you broke it shaving a tenth off your lap time at the local board track seems to be lost to history. We're guessing no. But what about today? Do new-car warranties in 2017 cover cars when they are driven on race tracks? We researched the warranties of 14 auto brands to find out, and the answer is yes, no, maybe, depending on the brand, in some cases the model, and whether or not your car is modified from stock. Acura has been out of the high-performance car game for a number of years, but jumps back into the party in 2017 with its hybrid-powered $173,000 NSX supercar. And Acura's warranty, as well as Honda's, clearly states that it does not cover "the use of the vehicle in competition or racing events." View 33 Photos So we asked Sage Marie, Senior Manager of Public Relations for Honda and Acura. "If the car is stock, the warranty covers it on a track just as it does on the street. No question," he told us. "However, if the car is modified, say with slick tires or other components that would put higher stresses on the vehicle's parts and systems, then we would have to investigate the circumstances further." Marie went on to say the same would be true for any Acura model or Honda vehicle, including the new 2017 Honda Civic Si. This became a common theme. Chevrolet actually started this practice with the fifth-generation Camaro on the high-performance ZL1 and Z/28 models.

Submit your questions for Autoblog Podcast #321 LIVE!

We're set to record Autoblog Podcast #321 tonight, and you can drop us your questions and comments regarding the rest of the week's news via our Q&A module below. Subscribe to the Autoblog Podcast in iTunes if you haven't already done so, and if you want to take it all in live, tune in to our UStream (audio only) channel at 10:00 PM Eastern tonight.
Discussion Topics for Autoblog Podcast Episode #321
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