[Powertrain]

Corvette Grand Sport #002

"Old #12" wore 427 big block power installed by Penske in 1966. Earlier, in the 1963/64 time period of our restoration, power for Grand Sport #002 was provided by a 377 c.i.d. (stroked 327) small block. The Penske 427 was removed and preserved separately.

Although an original 377 engine is on hand, for vintage racing purposes an all-aluminum duplicate engine was built to 1964 specifications. Many original Grand Sport parts were incorporated including a correct cross-ram intake manifold for the 58mm Weber carburetors. The recreated 1964 did not disappoint on the dyno.

[Courtesy: Road & Track]
Grand Sport #002 - Notre Dame Show

Two slightly different versions of the cross-ram Weber manifold were used on the Grand Sport. This manifold is the late-1963 casting date type with a "0" prefix part number & the Winters Foundry "snowflake".

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Numerous types of cylinder heads were on the drawing board for the Grand Sport (cast iron heads, aluminum heads, hemi/dual plug heads, etc). It is believed that three types of heads were actually used on the cars - cast iron heads & 2 versions of aluminum heads (standard exhaust bolt pattern & angled pattern).

This is a set of "0" prefix aluminum heads, dated 1962, with standard exhaust bolt pattern and fitted with hardened seats & 2.02/1.60 valves.

A second set of carb linkage was fabricated for the 58mm Webers by using an original set for patterns.

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Linkage components refinished and ready to send for correct cadmium plating.
Two complete sets of 58mm Weber carbs restored with proper I.D. plates & fuel inlet fittings.

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The Grand Sport Corvettes were fitted with three different "generations" of Weber carburetor adaptors.
    Left to Right:
  • 1st generation - August 26, 1963
    (aluminum, angled carbs)
  • 2nd generation - November 25, 1963
    (aluminum, angled carbs)
  • 3rd generation - January 17, 1964
    (magnesium, horizontal carbs)
Research of photos indicated that G.S. #002 was equipped with the 2nd generation Weber carb adaptors when Arkus-Duntov completed the car.

A new complete set of aluminum adaptors was fabricated.

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Filler necks were added to stock '64 valve covers. After chrome plating & polish, they are identical to the ones used on the car at the Notre Dame show.
G.S. #002 was equipped with a 1963 dated ("non-production line" I.D. plate) distributor and a "prototype" 1963 transistorized ignition system (complete with special wiring harness & unique foil decal).

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New old stock, prototype transistorized ignition coil for G.S. #002.
Correct TRACO remote oil filter adaptor.

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Rear differential cover for G.S. #002 after restoration.

Note the correct fasteners and "as cast" aluminum finish. Attention to the smallest of details required that even the factory "centerline" scribe mark be preserved (arrow).

Assembled differential as original. A 3.55 gear set is installed.

The red epoxy areas are where a special "oil deflector" shield was originally installed to provide better lubrication to the ring & pinion.

It is not known for certain when this modification was done to G.S. #002 but history tells us that Arkus-Duntov & Chevrolet Engineering first learned of a problem with the Grand Sport differentials at Nassau in 1963.

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Most original 1960's Weber carbs had short, nickel plated velocity stacks. G.S. #002 had special "extended length" chrome plated stacks that brought the total overall individual intake runner length (from the valve) to a phenomenal, torque enhancing, 23 inches!
Just like 1965, special rubber plugs with brass chain protect the Webers.

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G.S. #002 had three basic types of exhaust systems over the years:
  • Production style cast iron manifolds with single pipe side exhaust. (1962-63 coupe configuration)
  • Chevrolet Engineering fabricated, 4 tube header, side exhaust system. (1964-65 "377" roadster configuration)
  • Stahl fabricated, 4 tube header, side exhaust system. (1966 "427" Penske-Wintersteen configuration)
Since G.S. #002 was restored to the 1964-65 "377" configuration, a new set of correct 4 tube headers were fabricated.
New header flanges were duplicated in the milling machine to match those shown in photos of G.S. #002's engine back in 1965.

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The three Grand Sport coupes had a modified, "pancake" style collector pipe where the primary tubes entered, but the two roadsters had a more standard "round" collector pipe, as shown here.
The correct style collector flanges & clamps were fabricated for G.S. #002 from original photographs.

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The two Grand Sport roadsters had different exhaust header routing than the three coupes. Research of photos indicated that the coupes had both right & left headers routed under the frame tubes. The roadsters differed in that the right side header snaked its way over the frame tube, as shown with the newly fabricated right side header for G.S. #002.
The driver's side header was correctly routed under the frame tube as shown here.

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Photos of G.S. #002 in 1965 indicated that the original "377" exhaust system was painted white. This finish was applied on the replicated system.
The "vintage race" 377 C.I.D. engine that was built for G.S. #002 is a combination of 1960's Chevrolet prototype parts and modern day technology.

For authenticity, the engine utilized the original GM crossram intake, 1960's weber carbs, original GM transistorized ignition system, old style "straight plug" aluminum cylinder heads and Chevrolet aluminum block.

The application of "state of the art" internal components & air flow modifications, resulted in this "vintage race engine" producing a very respectable 616 HP @ 6500 RPM & 516 LB/FT of torque @ 5750 RPM.

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The aluminum 377 C.I.D. small block & M22 transmission being lowered into place for the first time since 1965.
Close-up of Grand Sport small-block drivetrain as original for G.S. #002 as it appeared at the Notre Dame show.

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New old stock GM bellhousing, with the correct "large input flange opening" for the M22 transmission.
A 7.25" diameter, 3 disc clutch assembly was chosen for the restored G. S. #002 for several reasons:
  • Less rotating mass (inertia) & better "hook-up" for vintage racing.
  • Much safer than the stock "production line" components.
  • Allowed for the stock GM bellhousing & starter to be utilized.

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Rebuilt, "prototype" M22 4-speed transmission with factory "milled off" part number pad was installed.

A roller bearing 1st gear assembly was added to this rare transmission to extend its longevity during vintage racing.

Restored G.S. #002 chassis complete with 377 race engine, M22 transmission, & correct 4-tube header exhaust system.

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Chassis
G.S. #002 Home
Front Clip

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