Buick Gran Sport

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Buick Gran Sport, 1970 455 Stage 1
Buick GSX, 1970 455

The Buick Gran Sport or GS was a high-performance option package available on a number of Buick models, including the Riviera and Wildcat. A special version of one model was given the package's name as its model name.

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[edit] Skylark Gran Sport

The 1965 Skylark Gran Sport was the intermediate Buick Skylark with the Gran Sport option added. Although a 300 cubic inch engine V8 was already offered in the Skylark, the Gran Sport had the largest engine permitted by GM - a 400 in³ Buick V8. This engine was actually 401 in³ but called a "400" by Buick because that was the maximum engine size limit set by General Motors for the intermediate body cars. This engine produced 325 hp (242 kW) and 445 ft·lbf (603 Nm) and was known as the "nailhead" engine. Buick sold more than 15,000 Skylarks with the Gran Sport option that first year, and almost that many the next. It was renamed the GS 400 in 1967, and the Gran Sport became its own model in (about) that same year along with a new "400" engine quite different from the notoriously reliable but growingly obsolete nailhead engine design that was first introduced in 1953. Sales fell somewhat in the face of increasingly more hot and popular muscle cars from other marques when compared to those from the more stodgy and expensive Buick. Buick, however stepped it up a notch when introducing the Stage 1 option in 1969. This limited (less than 1,500 cars in 1969) version produced 340 hp (253 kW) and 440 ft·lbf (597 Nm). The name Gran Sport replaced the GS moniker with the 1973 Gran Sport, and was again revived in the late eighties on the FWD Skylark model with various performance options added.

[edit] Gran Sport 340/350

In 1967 Buick added a 340 in³ version, the GS 340 or GS California. It produced 260 hp (193 kW) and 365 ft·lbf (495 Nm), and less than 4,000 were sold. It was replaced the next year with the GS 350, and similar GS California; these used Buick's 350 in³ small-block engine. Sales of the little-brother GS doubled, and were up to almost 10,000 for 1970. The Gran Sport 350 outlived its big brothers, lasting until Gran Sport production stopped in 1975.

A baby brother Gran Sport 231 was produced in 1975.

[edit] Gran Sport 455

The 400 was replaced for 1970 with the 455 in³ Buick V8, used in the GS 455. The base model V8 produced 350 hp (260 kW) and 510 ft·lbf (690 N·m) at 2600 rpm. In the optional Stage1 trim it produced 360 hp (193 kW) and 510 ft·lbf (691 Nm) at a low 2800 RPMs. As with all American engines produced prior to the 1972 model year, these were SAE Gross ratings, which are generally significantly higher than SAE Net ratings, which are indicative of what actual production engines produce in their "as installed" condition (with all engine accessories and full exhaust system in place). Magazines from the period obtained a Trap speeds in the 105 MPH range for the 1970 test cars that were provided to the press. Those results, combined with subsequent engine dyno testing of a production-line stock 1970 Stage 1 in "Muscle Car Review" magazine in 2001, suggest that the 1970 Buick Stage 1's actual net output was roughly 360 SAE Net HP, leading some to suggest that the engine was truly "under-rated," relative to what was typical for the time. Reports of higher "actual output" (e.g. 415 HP) during the engine's development were likely the result of partially blueprinted development engines that were fitted with test headers and devoid of all power sapping engine accessories - a common practice in the pre-1972 "Gross HP" era.

The Stage 1 enigne option condisted of a more aggressive camshaft, unique cylinder heads, unique 4 barrel carb. more aggressive ignition timing and various other tweaks. The engine was available with either a firmer shifting Turbohydromatic 400 and a standard 3.42:1 posi-traction rear differential. A 3.64:1 rear ratio was standard when delivered with a Stage 1 and manual transmission with optional gears available to at least a 4.33:1 ratio.

The relatively unknown and expensive when new 1970 GS 455 Stage 1 drew a great amount of attention and controversy in the muscle-car world when in the 1980's it was listed as faster than any of the Chrysler Hemi cars in the original "50 fastest muscle cars" list. This Hemi Vs. Stage-1 controversy has prompted several contests to settle the controversy which continues today and has been a great boon to car magazine sales over the years.

There was also a very rare Stage 2 option produced. This was a dealer-installed package that was first offered in 1969 and included a cam, headers, intake manifold, high compression forged pistons, hollow pushrods, and some calibration changes to the ignition and carburetor. If the car was ordered with the Stage 2 package, the parts were shipped with the car but were installed at the dealership. In 1970(?) the Stage 2 package included special, round exhaust port Stage 2 heads, matching Kustom brand headers, a radical cam, high compression forged pistons, Edelbrock B4B aluminum intake, and other equipment for racing. Few stage 2's were ever used on the street and Buick only ever factory assembled 3 Stage 2 test units. One of which was a factory GSX test mule with 4 speed manual transmission used for speed testing. The Stage 2 package's existence was not made public until 1972 when the Stage 2 parts could be ordered in any combination. There is little documentation about the 2 Stage 2 cars that were sold. One was campaigned by Kenne-Belle and the other was knows as the Jones-Benesik car. The Jones car was the one that was known to have been delivered as a Stage 1 car with all the Stage 2 components in the trunk in GM boxes.

Output and sales for the assembly-line cars were down after 1970 largely due to reduced engine compression ratios and a change from gross to net horsepower ratings. In later years, air quality regulations further limited the power in part due to the addition of catalytic converters and single exhaust pipes. However, Stage 2 parts were available over the counter although the stage 2 heads were discontinued after about 75 sets were produced. The discontinuation was due to porosity problems with castings.

[edit] GSX

GSX / GSX Stage1 was the optional high performance package available on the GS 455 starting in 1970. It was only available with the standard big block 455 engine or the optional Stage1 engine the first year. It was not a very popular model and only 678 GSX'S were produced in 1970, of those 400 were ordered with the Stage1 option. GSX or any GS Stage-1 performance is comparable to that of the 'Hemi' 'Cuda with a much more luxurious car. This is partly due to the light weight of the 455 which is roughly 150 lb (68 kg) less than the Chevrolet 454. Quarter mile times in the 13.30s were reported in numerous magazines in 1970. Production dropped in 1971 to 124 total, and 44 in 1972. These numbers include the available for 1972 350-4 bbl option, the standard 455, and the Stage 1 engines. The Buick 455 Big block V8 with stage one heads produces between 350-370 hp and 510 ft·lbf (690 N·m). of torque.

In 1970, the GSX option was available in only two colors, Saturn Yellow and Apollo White (in 1971 and 1972 other colors were available for the GSX). All GSXs had the distinctive full body length black stripe that crossed over the rear spoiler and was outlined in red pin stripes. A large area of the hood was also black with a hood mounted tachometer (Buick engineers disliked the hood tachometer because it was a Pontiac part) and black front spoiler. Also standard equipment were black bucket seats, floor shifter, wide oval tires, quick ratio steering and anti-sway bars. Some other options were automatic transmission or four speed manual.

After 1970, the GSX became an option that was available on any Gran Sport. Many GSXs survive to this day and can be seen at the Buick Gran Sport Nationals held annually in Bowling Green, KY in the middle of May along with many other examples of '60s, '70s and '80s Buick performance models.

The GSX and big-block V8 were dropped after 1974. In 1974, the GSX consisted of a trim package on Buick's small, X-bodied Apollo.

[edit] Riviera GS

The Riviera GS was a high-performance version of the Buick Riviera, produced from 1965 through 1975.

In 1965, it was called Riviera GranSport and the later models were still officially called Gran Sport but showed GS badges instead of GranSport. Unlike the mid-size GS models, the Riviera and Wildcat GS package included a standard 3.42 positraction rear axle until 1973. The 1965 (and optional in 1966) Riviera GranSport also came with a 425 cubic "Super Wildcat" engine, with dual carbs and dual snorkel chrome air cleaner. You could add H2 option (Ride and handling package) for even better road handling. Shorter gear ratio for steering, 1 inch lower suspension.

[edit] Wildcat GS

Another GS option package was available on the Buick Wildcat and Wildcat Custom, hardtop and convertible. The GS package included a 3.42 ratio posi rear, variable rate suspension springs, quick ratio steering box, heavy duty sway bars, and a switch-pitch turbo-hydramatic 400 transmission. The addition of the Y48 option gave the purchaser a pair of Carter AFB four barrel carburators, and finned aluminum valve covers on the 425 nail head engine. This was a one year only option. The Y48 option was delivered in the trunk and installed by the dealer.

[edit] Century Gran Sport

In 1973-75 and in 1986, there was a Century Gran Sport.

[edit] Regal GS / Regal Gran Sport

From 1988 to 2004, there was a Gran Sport version of the Regal. The 1988 body style was available with the 3,800 cubic centimetres (230 cu in) Series I V6 producing 170 horsepower (130 kW). The 1997-2004 body style featured a 3.8L Series II supercharged V6 with 240 horsepower (180 kW).

[edit] External links

Retrieved from "http://en.wikipedia.org/wiki/Buick_Gran_Sport"
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