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Coupe Build/Price: https://www.chevrolet.com/performanc...and-price/trim
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  • Motortrend Video

    Motor Trend LT2 vs. LT1: 8 Ways the C8 Corvette’s LT2 Engine Bests the C7’s LT1

    Motor Trend Staff

    22 hrs ago
    Slide 1 of 184: 2020-Chevrolet-Corvette-Stingray-LT2-62L-V8-02.jpg
    Next SlideFull screen
    1/184 SLIDES © Motor Trend Staff 2020-CHEVROLET-CORVETTE-STINGRAY-LT2-62L-V8-02.JPG

    By now the C8 Corvette's performance advantage over previous Stingrays (and even some higher-output models by some measures) has been well and truly documented. Obviously, a lot of the improvement is due to the engine's migration (at long bloody last) aft to a position where its mass actually helps with acceleration, braking, and handling.

    But improvements to the LT2 engine itself also helped earn it the highest SAE-certified output of any naturally aspirated Corvette ever. Of course, most of them were enabled by the vastly different packaging environment of the new amidships placement.
    Click to expand



    00:15
    03:53


    First Test: 2020 Chevy Corvette C8

    Here are eight important areas where the C8 Chevy Corvette's LT2 engine improved greatly over the LT1.

    Everything you could possibly want to know about the 2020 Chevrolet Corvette and its predecessors is RIGHT HERE at motortrend.com/corvette. Better Intake Breathing (3 percent performance boost)

    Packaging the LT1 engine's intake manifold beneath a hood that drivers could see out of cramped the intake runners, forcing the number seven and eight runners considerably shorter than others. The new intake plenum is much larger (14.1 versus 11.1 liters) and all of the runners are 210 mm long, instead of some measuring 225 mm and others 155 mm. The path into the valve is also smoother now and overall flow is four percent better. Overall, the 2020 Chevy Corvette Stingray with the performance exhaust has 495 hp and 470 lb-ft of torque. Lower-Restriction Exhaust (1 percent performance boost)

    In order to sneak the exhaust gasses down between the engine and frame rails and out the back of a front-engine Corvette the LT1 used cast manifolds with two separate catalysts to get the emissions job done. In the roomy new C8 engine compartment, the exhaust can come up and back through fabricated tubular four-into-one headers of equal and optimal length (330 mm), which also saves 200 precious grams of weight. The shorter overall exhaust length enables a single split-volume catalyst per bank with 'bricks' that are drilled for better flow and roughly 3psi less exhaust restriction. © Motor Trend Staff 2020 Chevrolet Corvette 3LT Z51 engine detailRevised Cam Profile and Phasing

    Now that the exhaust flows about as freely as the intake, the exhaust valve lift is increased by 1mm to match the intake's 14.0-mm lift, which improves exhaust valve flow rate from 122 to 125 grams/second. Duration is also increased, and the range of authority of the cam phasing is now 62 degrees (though the controller seldom orders more than 50 degrees). Wide Range Air-Fuel Sensor

    Replacing the upstream oxygen sensor with a WRAF allows much finer mixture control. This enabled a great improvement in idle quality, which might otherwise have degraded with the more aggressive cam profile. All these changes helped to reduce the engine-out (pre-catalyst) emissions, and post-cat emissions improve by 25 percent (from Bin 160 to Bin 125), thanks largely to the close-coupled full catalyst. New Dry-Sump Lubrication

    The dry-sump system is entirely new and now features:
    • Oil return passages plugged with separate 14 cc/revolution fixed-displacement scavenge pump up in the valley of the vee
    • Two new fixed-displacement 26 cc/rev gerotor pumps provide two-stage scavenging from the sump
    • Variable-displacement supply pump that provides up to up to 20 cc/rev
    • Composite sump tank saves 1 kg and moves from chassis-mount to direct engine mounting, eliminating supply lines and the potential pressure losses that can entail (this is a world-first—Ferrari engine-mount tanks still use distribution lines)
    • The oil circuit now requires just 7.5 quarts, more than 2.2 quarts less than in the LT1.
    • Scavenge system supports 1.25g acceleration in any direction—LT1 had potential starvation under braking in a corner at 1.0g
    • Oil pan features thinner walls and is 1.5 inch shorter to save 2.6 kg, and the oil cooler/filter adapter saves another 1 kg
    • Oil cooling circuit is 25 percent more efficient (providing 23 kW of cooling versus 18)
    New Flywheel

    Positioning the engine 1 inch closer to the ground required the flywheel to shrink, requiring a new starter pinion gear ratio. And at the front of the engine there's a new aluminum hub balancer. Different Cylinders Deactivated

    The LT1 shut down numbers 1, 4, 6, and 7; LT2 shuts off 2, 3, 5, and 8 simply for packaging reasons. More interestingly, the deactivation solenoids move from the bottom of the pushrods to the top. Tonawanda Pride!

    The engine is built in Tonawanda, and at the request of none other than Mark Reuss, each engine will bear a plaque proclaiming it "Built by Chevrolet Tonawanda, The Number 1 Team," inspired by the one Reuss recently replaced while restoring a Big Block V-8. 8 Ways the C8 Chevy Corvette's LT2 Engine Bests the C7's LT1

    • Better Intake Breathing (3 percent performance boost)
    • Lower-Restriction Exhaust (1 percent performance boost)
    • Revised Cam Profile and Phasing
    • Wide Range Air-Fuel Sensor
    • New Dry-Sump Lubrication
    • New Flywheel
    • Different Cylinders Deactivated
    • Tonawanda Pride!

    FOR REVIEW VIDEO CLICK LINK BELOW
    https://www.msn.com/en-us/autos/auto...lt1/ar-AAJXv3w

    Last edited by Frenzy36; 11-07-2019, 01:16 PM.
    Rocket City Florida

  • #2
    2 less quarts of oil means less weight and some $$ savings. The LT1 was prone to starvation resulting in blown engines during hard use so the upgraded pumps are a big improvement. Its amazing how 1 or 3 percent here and there can really add up. This has been going on in superbikes for years.
    GS7 Elkhart Lake Blue, Jet black/suede interior; Yellow stitching and belts. Z51 & Mag Ride; ZZ3 engine appearance; 3LT; Q8T Spectra Gray Tridents; J6E yellow Calipers;

    Comment


    • #3
      Thanks Frenzy36 for the find/post!
      GBA Black; HTO Twilight/Tension interior; Z51 & Mag Ride; E60 lift; 5ZZ high wing; 5VM vis CF ground effects pkg; FA5 interior vis CF; ZZ3 engine appearance; 3LT; Q8T Spectra Gray Tridents; J6N Edge Red Calipers; SNG Edge Red Hashmarks; VQK Splash Guards.

      Lifetime, annual contributors, and 20+ year members of National Corvette Museum.

      Comment


      • #4
        Thanks Frenzy36...GREAT post!
        Vette's owned: 99 Sebring Silver Convert - 10yrs, Just SOLD my 2008 Crystal Red Convert,w/cam, longtubes and Vortech supercharger for new C8 On order from Kerbeck at status 3000, 2/10/20 TPW. C8 Spec: TorchRed,2LT,Z51,FE4,E60,CF7,FA5,AH2,HUL,J6E,TUL,Q 8P,SC7,ER I,R8C

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