Chevrolet Camaro Z-28 Series 1

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Chevrolet Camaro

Chevrolet Camaro Z-28 Series 1

1967 - 1969
Country:
USA
Engine:
V8
Capacity:
302.4cu. in.
Power:
390 bhp
Transmission:
see article
Top Speed:
n/a (bloody quick)
Number Built:
n/a
Collectability:
5 star
Today, even the most ill-informed know the Z-28 designation referred to an engine option, a 302.4 cu. in., 290-hp V8, the heart of a sedan racing package. The option added US$437.10 to the Camaro's $2572.00 base price, but additional mandatory options, such as power disc brakes (front) and a four-speed close-ratio Muncie transmission, brought the sticker price up to a minimum of $3314.60.

Additionally, the Z-28 option included heavy-duty springs and shocks front and rear, shot-peened front ball studs, a rear radius rod, 15 x 6-inch wheels with 7.35-15 nylon red-stripe tires, and a pair of broad fore-and-aft racing. This equipment was brought together in the Camaro primarily for the Sports Car Club of America's sedan races, which were governed by Group 2 of Appendix J of the Federation Internationale de l' Automobile’s Sporting Code. Group 2 sedans were supposedly production touring cars, modified only slightly - in the interests of safety - for competition.

The manufacturer had to manufacture 1000 identical cars before the FIA would certify that it was a production car. The SCCA imposed some additional restrictions, including a maximum wheelbase of 116 inches, and a maximum engine displacement of five liters (305.1 cu. in.).

At the time Chevrolet had no intention of entering passenger cars in sedan races itself, but there was such a cry from road racing Chevy lovers that management was persuaded to make a suitable vehicle available and have it certified ("homologated”) for competition just as Chevrolet had done with the Corvette Sting-Ray in the sports car class.

Actually, the Chevy II would have made a more competitive basis on which to build a Group 2 sedan (because it was lighter), but Chevrolet quite rightly thought of the Chevy II as a family sedan and the Camaro as a sports car - and their marketing department no doubt needed the public think likewise.

The SCCA's five-liter displacement ceiling was what prompted the 302 cu. in. engine size of the Z-28. Until the Z-28, the Camaro was available only with a 250 cu. in. Six-cylinder engine (not powerful enough) and the 327 and 350 cu. in. V8s (over the limit). If the standard Chevy 283 cu. in. V8 had originally been offered with the Camaro, that's probably the engine Chevy would have homologated (that's out take, and may not be accurate), but starting from scratch, the opportunity to create a new engine with a displacement close to sedan racing's maximum proved tempting. And it could be easily built up from existing hardware. Chevy took the crankshaft from the 283 with its 3.0-inch throws, and put it in the 327 block with its 4.0-inch bore, and came up with the Z-28's 302 cu. in. displacement. (This bore/stroke combination had, by then, been used for years in Chevy engines in USAC sprint cars).

The Z-28's engine was special in several other respects. It had mechanical lifters, which were noisier than hydraulics, but allowed higher revs. The carburetor was a high flow capacity (800 cu. ft. per minute) Holley four-barrel, sitting atop a "high-rise" aluminum intake manifold, and fed from a plenum chamber picking up cool air from the grille near the base of the windshield - a trick previously invented by Chevy for their 427 cu. in. Mark II racing engine in 1963. The Z-28's heads, from the 327, featured large valves: 2.0 inches (intake) and 1.6 inches (exhaust). Dual-point transistor ignition, a 5-blade viscous-drive fan, and double fan belt pulleys were also standard on the Z-28.

The engineers encountered  some problems with the exhaust plumbing during development. Chevrolet had asked one of its big suppliers for a price on fabricated headers. The supplier, accustomed to working on 100,000-job lots, sheepishly came up with an initial estimate of $400. At the time you could buy headers for the Chevy 283/327 from practically any speed shop in the US of A for under $150. So, although the Z-28 option included tuned headers, although the at launch $437.10 price did not reflect this.

Under heavy acceleration, reaction to the engine's torque would tip the car counter-clockwise (viewed from the rear), unloading the right rear wheel. If the right side of the axle wasn't tied down, it could easily go haywire. One traction arm on the right side controlled axle judder, but the Z-28 was still prone to come off the line sideways.

Also, it would behave differently in a right hand corner than when turning left. Worst of all, under heavy braking the torque would be coming from the opposite direction, and the left side of the axle juddered violently. Under Group 2 rules, it wasn’t legal to add a traction arm, so competitors tended to use the left trailing link of a rear anti-sway bar (not an option, but legal in Group 2).

As a racing car  the Z-28 to did well. The 283/327 engine had been around long enough that extracting its maximum power was old hat for any experienced speed shop (souped-up versions of the 327 powered five of the six Can-Am winners in 1966), particularly as the choice of such key items as the camshaft and pistons was up to the individual Group 2 engine tuner.

Modified to the legal limit, the 302 engine was capable of 390 horsepower, as compared with the 380 hp of the Cougar 289 (with two four-barrel carbs), the 370 hp of the Mustang 289, and the 360 hp of the Plymouth/Dodge 273 installed in Barracudas and Darts. In fighting trim, the Z-28's weight was under 2700 lbs. Brakes, transmissions, suspensions and aerodynamics were roughly equal between the cars in this class.

The list of race-worthy options for the Z-28 included items like an aerodynamic spoiler-lip for the trunk lid, 7 x 15-inch cast magnesium wheels, and sintered metallic brake pads and linings, and choices of axle ratios from 3.07 to 4.88, with or without Positraction. Looking Back on it today, it seems pretty obvious that the Z-28 was intended to be Chevrolet's version of the Shelby Mustang - a Gran Turismo disguised as a Detroit sports car. The Z-28's performance was remarkably similar to the Shelby GT 350, at a price almost $1000 less. Of course, Carroll Shelby had by then had three years of experience with his Mustang, in that time learning to avoid some of the pitfalls that were new to the Camaro.

The engine was obviously the Z-28's strongest point. Pulling a slightly tighter gear than the SS 350 and with nearly 20 % less displacement, the Z-28 jumped through the quarter-mile 1.2 seconds faster, yet reached a slightly higher top speed. The 290-hp figure quoted for the Z-28 engine was ridiculously conservative; most road testers of the era claimed that it felt at least as strong as the 327 cu. in., 350-hp hydraulic lifter engine offered in the Corvette.

The 302 engine was without a doubt the most responsive American V8 then manufactured, although there was a trace of unevenness at low speeds because of the carburetor’s unusually large venturi area. Once it began to pull, however, it smoothed out and lunged forward like a 426 Hemi. The red-line on the tach was at 5500, which to the most part could be ignored. Those that could ignore it would find the engine revving quickly to 6000 rpm, with no sign of getting tight. The clutch engaged easily but smartly, and pedal pressure was ideal for high-spirited driving. The Munncie gearbox had the very close ratios (2.20/1.64/1.28/1.00) used in the high-performance Corvettes, and the synchromesh was absolutely un-beatable, except going into fourth. The shifter mechanism was as positive as a Hurst linkage, although not as stiff.

Reviewers also noted that drag racing starts would result in a lot of snaking around as the left hand single-leaf spring flexed. Pontiac used huge dual traction arms on virtually the whole Firebird line as standard equipment, so many opted for the easy solution of junking the Chevy part and bolting on a pair of Tiger Tamers. The braking ability was adequate, but not great. Comparing reviews of different cars of the era, the Z-28 required 293 feet to stop from 80 mph (.73G), which compared with the Camaro SS 350's 280 ft. (.76G), which had a braking system identical to the Z-28's, and with 287 ft. (.74G) for the 428 cu. in. Shelby GT 500.

Tests conducted some time after launch indicate that the stopping power of the Z-28 improved considerably, so it would seem the Chevy engineers were onto this initial teething problem pretty quickly. Today’s owners can of course really improve things by fitting good quality tires. If you are lucky enough to own one, then keeping it original will require you to fit Goodyear 7.35-15 which were best described as average.

In most other respects the Z-28 test was identical to the SS 350 – there was a vinyl top, custom interior, console, AM radio, tinted glass, Rally Sport package (peek-a-boo headlights), and some other trick stuff that didn't make it go any faster. All the other options normally available for the Camaro (except air conditioning), were available with the Z-28. We all know today that the Z-28 is a very appealing car; as tough and purposeful as a jet fighter, but a car you could be happy living with. There were a few niggles on the early production examples, but most were well sorted quickly enough. Today they are highly prized – and rightly so...

First Generation Chevy Camaro VIN Decode

The 1967 Camaro was the only model to have the Vehicle Identification Number (VIN) tag mounted to the door hinge pillar. VIN tags on later models were visible through the drivers side windshield. Unfortunately, there is no engine information contained in a Camaro VIN until 1972.

-
-
Engine
Body Style
-
Year
Plant
-
-
-
-
-
-
1
2
4
3
7
7
N
1
0
0
0
0
1
3=6 cyl
4=V8
3=Coupe
6=Convertible
Last Digit
N=Norwood
L=Van Nuys
Increases by one for each Camaro built at each plant


1967-69 CAMARO VIN
Vehicle Identification Number (VIN) Example: 124377N100001
Third Digit Engine: 3 for 6 cylinder, 4 for V8
Fourth Digit Body Style: 3 for coupe, 6 for convertible
Sixth Digit Year: 7=1967, 8=1968, 9=1969
Seventh Digit Production Plant: N=Norwood,Ohio, L=Van Nuys
Last Six Digits increase by one with each Camaro built at each plant
1967 Chevy Camaros started with (100001)
1968 Chevy Camaros started with (300001)
1969 Chevy Camaros started with (500001)

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Also see:


Chev Camaro
1967 Chev Camaro Specifications
Chevrolet Heritage
Chevrolet Car Commercials
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