Not Just Another Corvette

Just how do these 5 specially built Corvette Grand Sports differ from a production 1963-1967 midyear Corvette? Quite a lot, as the following "part by part" comparison will show:

FIBERGLASS BODY:

While the overall shape of the Grand Sport fiberglass body may look similar to the stock Corvette, when closely examined they are actually very different.

The stock Corvette body is constructed from dozens of press molded individual fiberglass panels that are bonded together. This type of assembly results in "telltale details" or "characteristics" that experts always look for when analyzing an original midyear production body:

  • Evidence of the bonding seam "printing thru the paint" along the belt line.
  • Bonding strips under the fenders.
  • A mat finish to the underneath of the fiberglass.
  • A uniform return lip on all of the fender edges.
  • A tan or gray gelcoat finish on unpainted parts.

None of these production characteristics exist on a Corvette Grand Sport body! In an effort to save weight on the Grand Sport, Zora Duntov & his engineers came up with a totally different fiberglass body construction, while still retaining the general "look" of a production 1963 Corvette:

  • The Grand Sport body does not have any bonding seams or bonding strips.
  • The front clip & the rear clip are each one-piece hand laid fiberglass units.
  • The Grand Sport fiberglass is much thinner than the stock Corvette’s.
  • The fiberglass has a "cloth" finish to the underneath (due to the use of woven reinforcing cloth instead of mat).
  • The old fender lip returns were cut off and new wider fender flares were added in late 1963 (when the cars were re-worked by the factory).
  • To save weight, no gelcoat was used on the Grand Sport fiberglass, which results in a translucent appearance to the unpainted bodywork.
  • Front & rear inner fender well panels & door sills have a wood-grain texture in their surface finish, due to the factory using wooden "masters" to create these special panel molds.
  • The head light assemblies are fixed in the front bodywork (to save weight).
  • The front turn signals are mounted in recessed areas in the lower valance area.
  • All Grand Sports have a rear deck lid.

ALUMINUM/MAGNESIUM COMPONENTS:

Even though the Corvette is affectionately known as "America’s fiberglass sports car", many of the components used on the production Corvette are stamped steel, cast iron and steel forgings.

These include: the main structural "birdcage", door frames, radiator support, engine block & heads, differential, steering box, door/hood hinges, garnish moldings, braces & brackets, etc.

However, when the engineers designed the Corvette Grand Sport, all of those heavy steel & cast iron production components were put on a severe "diet". In an effort to save weight most of these parts were made of aluminum, and include the following items unique to the Corvette Grand Sport:

  • Body main structural "birdcage".
  • Door frames (coupes).
  • Door hinges.
  • Door latches.
  • Door strikers (coupe).
  • Interior door mechanisms (coupe).
  • Door handles (coupe).
  • Wiper grilles.
  • Wiper mechanism arms/linkage.
  • Wiper motor plates.
  • Interior garnish moldings.
  • Firewall brace (coupe).
  • Windshield lower garnish molding (roadster).
  • Fuel filler door (roadster).
  • Fuel filler cap (coupe).
  • Windshield washer bottle bracket.
  • Grille & side vent braces.
  • Instrument cluster gage housings.
  • Fresh air vent doors.
  • Fresh air control vent brackets.
  • Wheels (magnesium).
  • Knock off spinners.
  • Front brake calipers.
  • Front brake ducts.
  • Radiator core support.
  • Hood support mechanism.
  • Hood hinges.
  • Hood corner support brackets.
  • Inner fender panel braces.
  • Inner body braces
  • Interior mirror bracket.
  • Battery box (2nd generation)
  • Window frames (coupe).
  • Window channels (coupe).
  • Engine block (2nd generation).
  • Cylinder heads (2nd generation).
  • Cross-ram Weber intake manifold.
  • Weber carb adaptors (2nd & 3 rd generation).
  • Water pump (2nd generation).
  • Oil coolers (2nd generation).
  • Side exhaust insulation panels.
  • Steering box.
  • Differential housing.

STEEL COMPONENTS:

The designers of the stock Corvette had to achieve a balance between cost effective mass production, performance and longevity. This led to the use of many (relatively heavy) metal stampings, die castings in the manufacture of the production Corvette.

The designers of the Corvette Grand Sport worked off a clean sheet of paper for their design. Since the car was to be a limited production, non-D.O.T. compliant vehicle, they could stretch their creativity and focus their attention on the two closely related goals: light weight & performance. Their mechanical creations would function in the same spatial and geometric envelope as the stock Corvette, but they would be comprised of special materials & designs. The stock Corvette’s relatively heavy, mass produced stamped steel/welded frame would be replaced with a mandrel bent, thin wall steel tubing frame. Other more mundane stamped steel production parts such as trailing arms, foot pedals, shifter arms, etc., were made lighter by drilling them with "lightening" holes. The lighter the Grand Sport became, the lighter each individual component could be designed.

Some of the steel components unique to the Corvette Grand Sport include:

  • Main tubular frame (weighs less than 170 lbs).
  • Front upper & lower a-arms (fabricated sheetmetal wishbone type).
  • Front spindles (lightweight steel forgings).
  • Steering arm (lightweight steel forging).
  • Front & rear hubs (steel forgings, drilled for weight savings).
  • Rear trailing arms (drilled for weight savings).
  • Rear uprights (lightweight castings).
  • Rear camber brackets.
  • Brake & clutch pedal arms (drilled for weight savings).
  • Shifter arms (drilled for weight savings).
  • Tubular header system.
  • Seat framework (thin sheetmetal, with lightening holes).

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