• MARK II: CHEVY’S MYSTERIOUS 427!

    MARK II: CHEVY’S MYSTERIOUS 427!

    The real 427 Mystery Motor, unlike the Z11, was not available in a car, or to the public. You had to have serious NASCAR cred to get one of the 20 built.

    MARK II: CHEVY’S MYSTERIOUS 427!MARK II: CHEVY’S MYSTERIOUS 427!In the 1960s, Semon “Bunkie” Knudsen always seemed to be one step ahead of GM Chairman Fred Donner’s anti-racing missives. While running Pontiac, he had supported the Super-Duty Group that later, after he left, managed to get 421 Catalina Lightweights to drag racers before the axe fell. Then he moved on to Chevrolet in 1961 and supported the RPO Z11 drag racing and clandestine NASCAR 427 Mystery Motor projects. Both pure racing programs survived even though GM was officially out of racing. In the case of the Mystery Motor, everything was conducted through Chevrolet’s backdoor.

    The 427 Mystery Motor’s real function was that of a “bridge” between the old school W-Series 348-409 and the next-gen 1965 Mark IV big-block. It used the same bore/stroke block – 4.31-inch bore and 3.65-inch stroke – as the Z11 engine. But that’s where the similarity ends. Unlike W-Series engines with combustion chambers in the cylinders, the Mark II NASCAR engine utilizes canted and staggered-valve (Porcupine) heads with conventional chambers. This style head debuted in production 396-427 Mark IV big-block engines, affectionately dubbed “Rat Motors” by enthusiasts!

    Although developed primarily as a NASCAR race engine, Chevrolet did produce a singular variant for street applications, shown here with Ken Kayser, right, who had been Business Case Manager for the Mark IV big-block at Tonawanda. The Mark II in street trim, displayed for many years at GM’s Tonawanda, NY engine plant, was built to justify the expenses of building a racing-only engine. It is possible that at some point the project was referenced internally as RPO Code Z33. That would have been done only to disguise the 427 as an optional production engine so as not to attract unwanted attention. Interestingly, the Mark II engine was not produced at Tonawanda, the facility best known for Mark IV 396-427-454 engines.

    MARK II: CHEVY’S MYSTERIOUS 427!Part of the mystery surrounding the Mark II engine can be attributed to its planned public debut on February 24, 1963 at the Daytona 500. The first couple of engines were shipped to Smokey Yunick for use in Chevys being prepared for the 500. Junior Johnson and Johnny Rutherford were two high-profile racers originally slated to run this engine. However, Mark II 427s were in two Z06 Corvettes competing in the 250-mile American Challenge Cup, at Daytona on February 16! This was a race for sports cars and one-offs, not NASCAR stockers. Few people at the time realized that two of the split-window Sting Rays in the Challenge Cup had Mark IIs under their hoods. They were actually the first big-block Corvettes.

    Smokey Yunick prepared two Corvettes like NASCAR Grand National stockers and installed Mark II engines, sparked by magnetos with HD three-speed transmissions. Scheduled drivers were Junior Johnson and Rex White. During practice, Junior was not comfortable with how his Corvette was handling at 160 mph and decided not to drive. Bill Krause replaced him and went on to finish Third. He beat other Corvettes, Ferrari GTOs and Porsche Carrera Abarth GTLs. Paul Goldsmith driving a Pontiac Super-Duty 421 Tempest, won the three-hour race, followed by A.J. Foyt driving a Nickey Corvette! Bunkie was not unhappy!

    MARK II: CHEVY’S MYSTERIOUS 427!Johnny Rutherford driving Smokey’s #13 car finished 9th, the best finish for a Mystery-motored Chevy. Rutherford lapped the track at 165.14 mph, setting a closed course record. A broken distributor in the #3 Ray Fox/Holly Farms Impala sidelined Junior. Junior won 7 of the 55 Grand National races in 1963, including the Charlotte 400 in October. With no factory support for the engine, the car was parked in 1964. Junior’s iconic Impala, as last raced, survives today. It’s at RK Motors, Charlotte, NC,  https://www.rkmotors.com/

    The 427 Chevy Mystery Motor, along with other super-high-performance cars and engines from the period including the Z11 Chevy drag cars, are showcased in Marty Schorr’s new book, DAY ONE,  https://www.amazon.com/Day-One-Automotive-Journalists-Muscle-Car/dp/0760352364/ref=sr_1_1?s=books&ie=UTF8&qid=1493561421&sr=1-1&keywords=Day+One+by+Martyn+L.+Schorr

    The post MARK II: CHEVY’S MYSTERIOUS 427! appeared first on Car Guy Chronicles.

    Continue Reading…

  • ’19 CORVETTE ZR1: KING OF THE ROAD & TRACK!

    ’19 CORVETTE ZR1: KING OF THE ROAD & TRACK!

    The ‘19 Corvette ZR1 set a production-car lap record on the 4.1-mile Grand Course West at Virginia International Raceway with a time of 2:37.25.

    ’19 CORVETTE ZR1: KING OF THE ROAD & TRACK!’19 CORVETTE ZR1: KING OF THE ROAD & TRACK!Along with a harness bar and track seats with five-point harnesses, the record-setting stock ZR1 coupe was equipped with the available paddle-shift eight-speed automatic and ZTK Performance Package. The ZTK package includes an adjustable carbon-fiber High Wing, a front splitter with carbon-fiber end caps, Michelin Pilot Sport Cup 2 summer-only tires, and specific chassis and Magnetic Ride Control tuning.

    “The Corvette ZR1’s lap record at VIR, arguably America’s most challenging road course, is a testament to its supercar status,” said Mark Reuss, executive vice president, Global Product Development, Purchasing and Supply Chain. “On the racetrack, the ZR1 can compete with any supercar – at any price.”

    On sale this spring, the ZR1 coupe will carry a suggested retail price of $119,995 (price includes destination charge, but excludes tax, title and other dealer fees). The ZTK Performance Package will cost $2,995.

     The ZR1’s record lap at VIR was set during routine validation testing earlier this month; with vehicle dynamics engineer Jim Mero at the wheel. The car was set up per the owner’s manual’s recommended track alignment and aerodynamic settings. As part of the validation, the ZR1 was finalizing its total of 24 hours of at-limit track testing, with multiple GM Performance engineers logging laps.

    ’19 CORVETTE ZR1: KING OF THE ROAD & TRACK!“The track had been empty since mid-December, so it was a bit slow when we started, but the conditions turned pretty quick at the end,” said Alex MacDonald, manager, Vehicle Performance. “On the heels of announcing our Z06 time of 2:39.77, the ZR1 lap time is the icing on the cake. It’s not too often you set a lap record during validation testing.”

    ’19 CORVETTE ZR1: KING OF THE ROAD & TRACK!

    The ZR1’s exclusive LT5 6.2L supercharged engine is rated at an SAE-certified 755 horsepower and 715 pound-feet of torque. It features a new, more-efficient intercooled supercharger system, along with GM’s first dual fuel-injection system, which employs primary direct injection and supplemental port injection. Compared to the supercharger system on the Corvette Z06 LT4 engine, the LT5 employs a larger, 2.65-liter supercharger that generates more boost while spinning at a slightly slower speed. That reduces heat to help maintain a lower air intake temperature for optimal performance. Four new radiators also help manage cooling in the ZR1, which features 13 radiators in all, including circuits for engine oil, transmission and differential cooling.

    Watch the 2019 Corvette ZR1 set lap record at VIR,https://www.youtube.com/watch?v=j7j1gCM6-5M

    The post ’19 CORVETTE ZR1: KING OF THE ROAD & TRACK! appeared first on Car Guy Chronicles.

    Continue Reading…

  • ’19 CORVETTE ZR1: IT’S GOOD TO BE KING!

    ’19 CORVETTE ZR1: IT’S GOOD TO BE KING!

    America’s sports car morphs into a contender for international Supercar honors.

    ’19 CORVETTE ZR1: IT’S GOOD TO BE KING!’19 CORVETTE ZR1: IT’S GOOD TO BE KING!In Dubai, United Arab Emirates, today, Chevrolet introduced the ‘19 Corvette ZR1, a supercar that boosts Corvette’s performance heritage with the highest power, greatest track performance and most advanced technology in its production history.

    “I’ve never driven a Corvette like this before, and nobody else has either, because there’s never been one like this before,” said Mark Reuss, executive vice president, Global Product Development, Purchasing and Supply Chain. “Its unprecedented performance puts all other global supercars on notice that the ZR1 is back.”

    The Corvette ZR1’s exclusive LT5 supercharged engine, rated at an SAE-certified 755 horsepower and 715 pound-feet of torque, is establishing a new performance benchmark. Further, the ZR1 elevates Corvette’s track capability with two wind-tunnel-honed aerodynamics packages, including an available High Wing that provides an estimated 950 pounds of downforce.

    ’19 CORVETTE ZR1: IT’S GOOD TO BE KING!The ZR1’s LT5 6.2L V-8 advances Corvette’s supercharging legacy, which began with the 2009 sixth-generation ZR1 and continued with the 2015 seventh-generation Z06. The LT5 delivers the highest output ever for a Chevrolet production vehicle, thanks in part to a new, more-efficient intercooled supercharger system that offers 52 percent more displacement than the Z06’s LT4 supercharger. GM’s first dual-fuel-injection system, which employs primary direct injection and supplemental port injection, helps the LT5 achieve its record output. Seven-speed manual and eight-speed paddle-shift automatic transmissions are available with the LT5. It’s the first time an automatic transmission has been offered in a ZR1.

     The ‘19 Corvette ZR1’s aggressive appearance is driven by function, contributing to its distinction as the fastest production Corvette to date. An all-new front fascia is designed to channel air for propulsion-system and drivetrain cooling, with four new radiators bringing the heat-exchanger total to 13. A special carbon-fiber “halo” hood is open in the middle to clear the LT5’s supercharger/intercooler assembly. Additional features, including aero packages with stanchion-mounted wings, help push the ZR1 harder onto the track for more confident handling and faster lap times. Top speed of the ZR1 is over 210 mph.

    ’19 CORVETTE ZR1: IT’S GOOD TO BE KING!“As the highest-performing Corvette ever, the ZR1’s design supports its capability in every way,” said Kirk Bennion, Exterior Design manager. “The new wings, for example, help generate more downforce without adding drag, enhancing road holding and top speed.”

    The ZR1 will offer two aero packages: a standard rear Low Wing, which delivers the highest top speed and helps generate up to 70 percent more downforce than the Z06’s base aero package. There’s also an available two-way-adjustable High Wing that offers maximum downforce on the track for the quickest lap times – about 60 percent more downforce than the Z06 with the available Z07 Performance Package. All models also feature a Chevrolet-first, downforce-enhancing front underwing.

    ’19 CORVETTE ZR1: IT’S GOOD TO BE KING!The adjustable High Wing is part of the new ZTK Performance Package, which also includes a front splitter with carbon-fiber end caps, Michelin Pilot Sport Cup 2 summer-only tires, and specific chassis and Magnetic Ride Control tuning for greater cornering grip. Both of the ZR1’s wings are tied into the chassis, like the Corvette Racing C7.R racecar, for strength and stability. The Corvette ZR1 introduced today also debuted a dynamic, available Sebring Orange Design Package. Centered on its Sebring Orange Tintcoat exterior color, the package also includes orange brake calipers, orange rocker and splitter accent stripes, orange seat belts, orange interior stitching and unique, bronze aluminum interior trim.

    ’19 CORVETTE ZR1: IT’S GOOD TO BE KING!The new design package complements the Corvette ZR1’s tradition of offering maximum performance with refinement and design distinction. The driver-focused, well-appointed cockpit includes standard leather-trimmed seats, with sueded microfiber inserts offered. Heated and vented Napa leather-trimmed seating is also available, as well as a carbon fiber-rimmed steering wheel, competition sport seats, Performance Data Recorder, Bose premium audio system and more. The ‘19 Corvette ZR1 goes on sale next spring, poised to take on the world’s best.

    Check out this ZR1 video, https://www.youtube.com/watch?v=F4TTZE1EQ10

    The post ’19 CORVETTE ZR1: IT’S GOOD TO BE KING! appeared first on Car Guy Chronicles.

    Continue Reading…

dd