1969 Camaro Z28 - Attitude Is Everything

Few automotive battles raged as fiercely as the “Ponycar Wars” of the 1960s. Ford’s Mustang launched a new market for personal sporty cars in 1964½, forcing GM to react with its Chevrolet Camaro in 1967. These two competed head to head in showrooms, stoplight matchups, dragstrips and road courses. And while the 35-year battle ended when GM retired the Camaro in 2002, the skirmishes these two competitors

fought reverberate today.

The most intense of these battles were conducted on the road courses of America and Canada in the Sports Car Club of America’s Trans-Am series. Introduced in 1966, the Trans-Am was open to four-passenger production sedans in two classes—2.0L and under and 2.0L to 5.0L. Ford commissioned Carroll Shelby to prepare a team of Mustangs for the first season’s competition against the Dodge Darts and Plymouth Barracudas running in the over 2.0L class. The Trans-Am series captured more than a passing interest with race fans and the automotive press, an impressive achievement for a first-year race series.

Watching with keen interest from the sidelines was Chevrolet’s Vince Piggins, one of the driving forces behind Chevrolet’s high-performance program. Before the first production ’67 Camaro was built at GM’s Norwood, Ohio, assembly plant, Piggins had already conspired with the SCCA to bring Chevrolet into the Trans-Am series, developing a special package for homologation.

Piggins’ first challenge was to homologate (certify) an engine that came in under the Trans-Am displacement limit of 5.0L (305 cubic inches). Chevrolet offered 283-ci and 327-ci engines, but nothing in between. The 283 wasn’t stout enough and the 327 was too large, but Piggins deduced that mating the four-inch bore of the 327 with the three-inch stroke of the 283 provided a displacement of 302.4 cubic inches. This was a tried and true combination that racers had used before, and it met the SCCA’s legal 305ci ceiling. It also meant that the 302 would inherit the intrinsic benefits of having a short stroke with an oversquare bore. A short-stroke engine can run at higher rpm for longer periods since there is less piston speed. That of course is what a race engine has to do—run for sustained durations at high rpm.

The small-journal, cast-iron block for the 302 was also shared with the 327 and the 350 engines in 1967. The crankshafts were forged steel and tuftrided for high-rpm durability. The rods were shot peened and mated to 11.0:1 domed-aluminum pistons with notched valve reliefs. The iron heads featured big 2.02-inch intake and 1.60-inch exhaust valves with wide passages and big ports to produce mid- and high-end horsepower response. The 302’s “30/30” camshaft was lifted from the 375hp Corvette 327 fuelie engine and designed for use with solid lifters.

A big 800-cfm, dual-pumper Holley carburetor was bolted to a tuned-runner, dual-plane aluminum intake manifold with the front crossover tapped for a temperature sensor. Log-style iron exhaust manifolds were standard with headers optional. A single point Delco-Remy ignition was standard with a transistorized ignition optional. Chevrolet blatantly underrated the 302’s horsepower at 290 and torque an equally silly 290 lb-ft. In reality, the production engines generated over 375 hp, with power coming on strong from 3,500 to 6,500 rpm and still pulling at 7,000 rpm.

Piggins’ concept of using off-the-shelf components to build both a spirited performance street engine and a wicked race engine had another advantage—he could come to market with a production engine at significant cost savings. That would make it easier to sell the program to Chevrolet management. The rest of the package consisted of a heavy-duty radiator, quick steering, 15x6 wheels on 7.35x15 nylon red stripe tires, a four-speed Muncie M21 close-ratio manual transmission, special springs and shocks, a 3.73:1 rear axle and special wide stripes on the hood and rear deck lid.

Mandatory options included power brakes with front discs and metallic rear drums. Chevrolet Product Planning assigned it the next available RPO package number on the list—Z/28. The RPO number became the model name for Chevrolet’s Trans-Am contender.

The Z/28 was released on December 29, 1966, just in time to run in the 1967 Trans-Am series. Its public introduction was low key, and many Camaro buyers who didn’t see the magazine coverage of the Z/28 weren’t aware it was available. The Z/28 was lost in the overall onslaught of Camaro promotion as GM bombarded the market to overtake the Mustang. The Z/28 option, costing $358.10, was available only in coupes and just 602

were sold.

Refinements were made to the 302 engine for 1968. Some of these upgrades came at the beginning of the model year, while others were rolled into production during mid-year. The 302 block was still shared with the 327 and the 350 engines, however it now boasted larger journals and a large journal crankshaft (2.10-inch rod journals and 2.449-inch main journals). First-production rods featured pressed pins and larger rod bolts, while second-production rods were changed to floating wrist pins. Pistons were also changed in mid-year. First-production 1968 302 pistons were similar to 1967 units, however the domes were notched across the entire head of the piston. Cylinder heads and camshaft usage

remained unchanged.

What the high-winding 302 lacked in low-end torque was made up in thrilling mid-  and top-end acceleration. “Above 30 mph,” Car Life noted in a 1968 road test, “on winding mountain roadways, back country lanes and the rest of the types of roads that make driving worth doing, the Z/28 Camaro is an exhilarating vehicle. The Z/28 engine is a jewel, an outstanding performer by any yardstick.” The word was spreading about the hot Z/28 package, and sales rose to 7,199 units. The package price also rose to $400.25.

The biggest news for 1968 was the $500 cross-ram package homologated for Trans-Am competition and offered over-the-counter for the Z/28. The cross ram had first been conceived in 1966 for use with the big-block with conversion to small-block application taking place in the summer of 1967. Actually intended more for race use, customers could purchase and install the cross ram for street use themselves or have the dealer install it for them. Good for at least an additional 25 hp, the cross ram started with a special, dual-quad aluminum intake manifold with tuned runners and featured a pair of Holley 600-cfm double pumpers. The cross ram lacked manifold heat crossovers or chokes for the carburetors and was difficult to drive on the street. Its true purpose was on the racetrack, where it could add more horsepower to the high-winding 302.

The cross ram used a cowl-induction air cleaner and plenum to take advantage of the cooler, high-pressure air located at the base of the windshield. This cool air provided a denser charge and more power. While it was great on the racetrack, most testers found it impractical for street use.

“If the Z/28 isn’t a bona fide racing car—in street clothing—then we’ve never seen one,” observed Road & Track. The cross ram was available over Chevy dealers’ parts counters in December 1967, in time for Chevrolet to homolagate it for 1968 SCCA competition. By the end of the 1967 season, the Penske/Donahue team had sorted out the gremlins in their Z/28 and, thanks to improvements like the cross ram, won the 1968 Trans-Am championship.

The Z/28 truly came into its own in 1969. “News of Roger and Mark’s Trans-Am expedition has finally reached the Chevrolet marketing minions,” noted Sports Car Graphic, “and they’ve caught the fever.” After two years of racing and dozens of magazine road tests, Chevrolet marketing was finally getting behind the Z/28 and carrying the word from Detroit to dealers nationwide.

The Z/28 went through a transition to becoming a balanced street performance car rather than an uncivilized brute wearing painted suspenders.

When it came to the 302 engine, the Z/28 was not without its detractors. The complaints didn’t stem from the engine’s innate ability to wind to high rpm. Instead, questions arose about the 302’s merits as a street performance engine. Corvette Chief Engineer Zora Arkus Duntov called the 302 “an artificial engine built to meet an artificial class limit.

For 1969, the Z/28 Special Performance Package was basically unchanged from 1968, however the 302 engine received a few internal improvements. The block now had thicker main bearing webs, four-bolt mains and a large journal crankshaft. The intake manifold was redesigned and the water pump assembly was longer and deeper. While headers (Z/282) and plenum air-induction (Z/284) options had been cancelled during 1968, they were still offered over the counter for 1969.

Within the context of Trans-Am racing, however, the 302 proved itself to be a spectacular power plant. On the street, the 302 was cantankerous in cold weather and was undriveable below 3,000 rpm. The driver had to constantly keep rowing back and forth through the gears to keep the rpm up.

Early production ’69 Z/28s had the ’68-style decklid stripes and spoilers. The ’68 production spoilers were slightly shorter than the wider ’69 rear and weren’t replaced by second-production units until October 1968. Inside, when a tachometer was ordered, it had a 7,000-rpm limit and a 6,000-rpm redline.

These were replaced with 8,000-rpm tachometers with 6,500-rpm redlines during the model year. The D80 rear decklid spoiler and front chin spoiler was now included in the Z/28 package. For those who wanted to cruise the boulevard incognito, the wide stripes could be deleted.

In mid-December, Chevrolet released the RPO ZL2 Special Ducted Hood (known as the “Super Scoop”) as a $79 option. The ZL2 hood, designed by Larry Shinoda, featured a high-rise center section that ended with a rearward-facing duct that drew high-pressure air from the cowl into the carburetor through an underhood plenum. The factory ZL2 hoods were stamped steel with special bracings around the round plenum opening that allowed the air cleaner to fit within. The Heavy-Duty Service fiberglass hood was available over the counter for use with the cross ram. It used the same cowl induction technique as the production hood, however the underhood was molded specifically to mate to the foam seal that surrounded the dual carbs. An adapter package was released to use the Heavy-Duty Service hood with the four-barrel setup. It was an instant hit, ordered by 10,026 buyers.

Aside from the Corvette, the Camaro and the Z/28 were the only American production cars in 1969 to offer factory-installed four-wheel disc brakes. The Camaro setup (RPO JL8) cost $500.30 and was plagued with OE supplier parts problems. That shortage made delivery difficult and kept bumping the price of the option upward. Consequently, only 206 sets of four-wheel discs were installed at the factory when the option was canceled in mid-July 1969. A Heavy-Duty Service four-wheel brake package was also offered over the counter.

Savvy option manipulators who wanted the strongest setup for racing could order the RPO JL8 brake package on the car and the Heavy-Duty Service four-wheel brake package over the counter and install the Heavy-Duty Service rear axle assembly in place of the JL8’s rear axle. The benefit was to utilize the larger diameter axle shafts and bearings, which were better suited for the rigors of racing.

The Z/28 reached its zenith in 1969. In Trans-Am racing, the Penske team with Mark Donahue at the wheel crushed Ford to win its second series championship. Chevrolet marketing and sales finally got behind the Z/28 for 1969 and raised dealer awareness of this hot ponycar package. On the street, where a performance car’s reputation was both made or broken, the Z/28 became a favorite, and sales reflected this with 20,302 sold during the extended 1969 sales year. That sales total wasn’t broken until the ’78 Z/28 tallied 54,907 units.

Chevrolet collector Rick Treworgy in Punta Gorda, Florida, owns the Garnet Red ’69 Z/28 shown here. It is equipped with the Cross Ram induction system, M22 heavy-duty close-ratio four-speed gearbox, tube headers, power steering, tilt-steering column with wood-grained steering wheel and special console instrumentation.

• PERFORMANCE

• THE REAL NUMBERS?

According to Chevrolet, the 302 produced 290 hp @ 5,800 rpm and 290 lb-ft of torque @ 4,200 rpm. There’s no question the 302 was underrated, but by how much? Insiders talk about 375 hp at 6,800 rpm. Road testers could take the 302 to beyond 7,000 rpm and the engine was still pulling. Keeping the horsepower rating low kept the insurance premiums down for youthful drivers and was a transparent foil for SCCA specifications.

• BETTER BRAKES

Thanks to the research and data collected with Donahue’s race car, Chevrolet engineers developed a four-wheel disc package that became available in March of 1968 as a “Heavy-Duty Service Package” to conform to SCCA/FIA rules. This over-the-counter service option was primarily geared for racers, however it was suitable for dealer or customer installation.

• ’69 Z/28 PRODUCTION

20,302

• SUPERIOR SPOILER STUDY

During the 1968 season, the Penske crew was invited to bring their Camaro race car back to Detroit for a vehicle dynamics analysis by Chevrolet Engineering. While the race car was at GM’s Milford, MI, test facility, Chevrolet Engineering gathered new data on spoiler position and angles for application on the ’69 Z/28.

PHASES ANDCHANGES

The Z/28 option package went through a variety of configurations during the extended 1969 model year, which lasted from the car’s introduction in September 1968 to the end of the model run in February 1970. Changes were made primarily to the exhaust and brake systems:

Z/28 Option Package – Dated September 26, 1968

Includes 302-inch V-8 engine, dual exhaust with deep tone mufflers, special front and rear suspension, rear bumper guards, heavy-duty radiator and temperature-controlled fan, quick ratio steering, 15x7 rally wheels, E70x15 special white-lettered tires, 3.73:1 ratio axle and special rally stripes on hood and rear deck. Available only when four-speed transmission and power disc brakes are ordered. Positraction rear axle recommended. Package price $458.15.

Z/28 Option Package  – Dated October 18, 1968

Includes 302-inch V-8 engine with bright accents, chambered dual-exhaust system, Z/28 emblems on grille, front fender and rear panel, special front and rear suspension, rear bumper guards, heavy-duty radiator and temperature-controlled fan, quick ratio steering, 15x7 wheels with trim rings, E70x15 special white-lettered blackwall tires, special paint stripes on hood and rear deck. Available only when four-speed transmission and power front or four-wheel disc brakes are ordered. Positraction rear axle recommended. JL-8 (four-wheel discs) recommended. Package price $458.15.

Z/28 Option Package – Dated January 2, 1969

Includes 302-inch V-8 engine with bright accents, dual exhaust, Z/28 emblems on grille, front fender and rear panel, special front and rear suspension, rear bumper guards, heavy-duty radiator and temperature-controlled fan, quick ratio steering, stripes on 15x7 wheels with trim rings, E70x15 special white-lettered blackwall tires and special paint on hood and rear deck. Available only when tachometer gauge or special instrumentation, four-speed transmission and power front or four-wheel disc brakes are ordered. Positraction rear axle recommended. JL-8 (four-wheel discs) recommended. Package price $473.95

Z/28 Option Package – Dated April 1, 1969

Includes 302-inch V-8 engine with bright accents, chambered dual-exhaust system, Z/28 emblems on grille, front fender and rear panel, special front and rear suspension, rear bumper guards, heavy-duty radiator and temperature-controlled fan, quick ratio steering, 15x7 wheels with special center caps and trim rings, E70x15 special white-lettered blackwall tires, auxiliary front valance panel and rear deck spoiler, plus special paint stripes on hood and rear deck. Available only when four-speed transmission and power front or four-wheel disc brakes are ordered. Positraction rear axle recommended. Package price $506.15.

Z/28 Option Package – Dated September 18, 1969

Includes 302-inch V-8 engine with bright accents, dual exhausts with bright tips, Z/28 emblems on grille, front fender and rear panel, special front and rear suspension, rear bumper guards, heavy-duty radiator and temperature-controlled fan, quick ratio steering, 15x7 wheels with special center caps and trim rings, E70x15 special white-lettered blackwall tires, auxiliary front-valance panel and rear-deck spoiler, plus special paint stripes on hood and rear deck. Available only when tachometer gauge or special instrumentation, four-speed transmission and power front-disc brakes are ordered. Positraction rear axle recommended. Package price $522.40

Z/28 Option Package – Dated November 3, 1969

Includes 302-inch V-8 engine with bright accents, dual exhausts with bright tips, Z/28 emblems on grille, front fender and rear panel, special front and rear suspension, rear bumper guards, heavy-duty radiator and temperature-controlled fan, quick ratio steering, 15x7 wheels with special center caps and trim rings, E70x15 special white-lettered blackwall tires, auxiliary front-valance panel and rear-deck spoiler, plus special paint stripes on hood and rear deck. Available only when tachometer gauge or special instrumentation, four-speed transmission and power front-disc brakes are ordered. Positraction rear axle recommended. Package price $522.40