Motorsports News by David Vodden

Ken Roczen won the Monster Energy Super Cross 450cc championship by three points over Hunter Lawrence in Utah last weekend. It was his first title after thirteen seasons in the 450 class in the popular off-season television motorcycle show.

Christian Lundgaard won the Indy car race on the road course inside the Indianapolis Motor Speedway. It was a good race where Lundgaard wanted the win more than David Malukas and demonstrated this by making a spectacular pass of Malukas to take the lead and the win. It was Lundgaard’s second Indy car win. Graham Rahal, Josef Newgarden, and Alex Palou completed the top five.

The 110^th running of the Indy 500 will feature qualifying this weekend followed by the greatest spectacle in racing on Sunday May 24^th. For all who grew up with the whole month of May being the Indy 500, the trimming of the schedule and addition of the road race was hard to take. As it turns out, these were beneficial changes that have helped sustain the world’s longest continually running auto race. I have adapted and now reluctantly accept no more qualifying bump day because there are only thirty-three cars entered. All of these thirty-three cars will start the race in one of ten rows of three to complete the traditional thirty-three car starting field. The race will be shown on FOX TV with my favorite race announcer, Alan Beswick, heading the on-air-team. Brazilian Helio Castroneves is seeking to become the only driver to win the “500” five times. Helio is fifty years old. At forty-nine, fearless Takuma Sato from Japan looms as a dark horse winner seeking his third 500. There will be fourteen countries represented in the field including a first from Norway in rookie Dennis Hauger. German driver Mick Schumacher, son of legendary Formula One Driver Michael Schumacher, will make his first start in the 500. Last years winner Alex Palou of Spain is the odds makers choice for the win. Of the twelve American drivers Newgarden tops the list for the win with Kyle Kirkwood and Alexzander Rossi earning honorable mention. Who will win? History says that the Indianapolis Speedway picks the winner in partnership with lady luck. This is the ultimate world auto race. It has not been equaled in status, presentation or drama. It is an American tradition known around the world from the first race in 1911 to today. Watch it even if you saw it in person in 2016 when Rossi won as a rookie driver by saving fuel. Anything can happen and will.

NASCAR had some great racing at the Watkins Glenn Road course in New York last weekend. Of the four races there, the O’Reilly event on Saturday was by far the best. Connor Zilisch beat his friend Jessie Love with a pass in the last turn on the last lap heading to the checkered flag. It was the third win in a row at the “Glenn” for the nineteen-year-old driver from North Carolina. Zilisch has won seven times in ten NASCAR road races. Tanner Gray, Ross Chastain and Brendon Jones followed Zilisch and Jones to the finish. On Friday, Kayden Honeycutt won the NASCAR truck race beating Zilisch in overtime by one second. Earlier Friday Honeycutt won the ARCA race. He scored four wins over the weekend, counting two more local stockcar race victories on Saturday and Sunday.

The Sunday Cup series race was the least exciting as Shane Van Gisbergen won as expected by seven seconds over Michael McDowell, Ty Gibbs, Chase Briscoe, Tyler Reddick, Austin Dillon, A. J. Almendinger, Kyle Busch, Austin Cindric and John Hunter Nemechek. Van Gisbergen made a pit stop late in the race and demonstrated his superior skill as a road racer by driving to first in twenty laps. His advantage comes from his late braking, trail braking and getting on the gas exiting a corner earlier than other drivers. The win put Van Gisbergen in sixteenth place above the Cup series playoff cutoff line by seven points.

The Watkins Glenn Road course puts on the best racing shows for NASCAR in all three divisions. From the start to the finish drivers must turn right and left, enter and exit seven very different turns by shifting, braking and accelerating better than the competition. Drivers make passes by stealing apexes and out braking the car in front. The track is very fast, can produce some hair-raising moves at speed and deliver wild crashes. There weren’t any crazy crashes this year but the O’Reily, Craftsman truck and the ARCA Menards races were thoroughly entertaining. Van Gisbergen’s drive to win in the closing laps was the best part of the CUP race.

NASCAR offers their version of the All-Star race this weekend at the one-mile, cement track, Dover Delaware Speedway. This annual television show features Cup cars in a totally different race format that does not offer series championship points. In other words, drivers can race all-out and not worry about dropping back in the 2026 thirty-six-race Cup series championship battle. The race pays one million dollars to the winner which is supposed to make the drivers crazy and drive like there is no-tomorrow. No points. Big money. Why not. Having Dover as the site for this annual event has generated some controversy. There is no positive dialog about this, only naysayers spewing that Dover is not a good racetrack for this kind of race or for any NASCAR races in recent years. Stay tuned.

Justin Sanders won the Dave Bradway Memorial last Saturday night at Silver Dollar Speedway in Chico. I watched it on Flo Racing because the promoters at Silver Dollar rejected my journalistic efforts to cover their races. This may have been the best race of the year at the Fairgrounds dirt track located next to COSTCO. Saunders beat many time World of Outlaw champion Brad Sweet to a popular repeat victory. Shane Golobic, Colby Copeland and T. J. Neto followed at the line.

“3rd-Generation Camaros & Firebirds”

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By the time Chevy retired the 2nd-generation F-body twins (Chevy Camaro and Pontiac Firebird) in 1981, they’d been in service since 1970. 12 models years is an eternity in the car business and the 2nd generation was well past long-in-the-tooth. Technology had moved considerably since the 1960s when the 2nd-gen cars were designed. And government-mandated fuel economy standards were becoming more demanding every year. The F-bodies had gotten bloated over the years and the playing field had also changed. Ford launched its new 3rd-generation Mustang on the Fox-body platform in 1979, and gone were the easy pickings provided by the Pintobased Mustang II that came before it. The new Fox Mustang handled well and was light enough to be fast even with the crappy engines back then. It was time for a change.

Even before the new Mustang launched, Chevy saw it coming and by 1977 work had begun on the next F-body. Even though there would be no commonality between the 2nd-gen’s F-body platform and that of the 3rd-gen it was decided they would name the new platform the F-body. By 1979 full-size clay models were being sculpted and hardcore engineering began. Wind tunnel and durability testing commenced in 1980. The result of all the wind tunnel work was a move away from the long-hood/short-deck look of the 2nd-generation to more of a wedge-shaped, aerodynamic profile. Production began in August 1981 at the Norwood, Ohio and Van Nuys, California plants and the first 1982 Camaros and Firebirds were delivered in September 1981.

The new cars were smaller overall. Where the prior two generations had 108-inch wheelbases, the 3rd-gen’s was 101”. Weight was down too, by nearly 500 pounds. This improved performance, handling, braking and most importantly fuel economy. Important to the government, anyway. The new shape netted dramatic improvements in the drag coefficient, dropping from .48 to .37 Cd, again benefitting fuel economy. This was a true fully monocoqued unibody and it was not only lighter but much stiffer than before, designed by computer and made of high-strength steel. The suspension was all new front and back. Gone were the old leaf springs replaced by a novel coil spring setup with two trailing arms, a pan hard rod and a torque arm mounted to the transmission. Gone too was the old recirculating ball steering box replaced by modern rack-and-pinion.

The sharp, angular lines and large flat surfaces were a complete departure from previous Camaros and Firebirds and was brilliantly executed. They were handsome cars when they came out and they still turn heads today. When it came to the exterior, the two sisters shared only the roof, windows, doors and windshield in common, everything else was unique to each car. Chevy opted for four rectangular seal beams tucked into coves in the nose. Pontiac elected to go with hideaway headlights very much like the Corvette’s, a first for the Firebird. Each had their own wheels. Of course under the skin most of it was the same. And for the first time, when it came to engines there was no differentiation between brands, both the Chevy Camaro and the Pontiac Firebird would have Chevy engines. It just wasn’t cost effective to produce two completely separate engine families to do the same job and compete against one another. It was a smart move. The Pontiac V8 engine family was getting long in the tooth anyway, in service since 1955.

The base Camaro and Firebird came standard with, believe it or not a horrible old 4- cylinder known as “The Iron Duke” wheezing out 90 hp from 1982-1986. It was followed by the almost as awful little 2.8-liter OHV V6 making 135 hp. It was an underpowered, grumbly little thing that was punched out to 3.1 liters in 1991. Of course all we care about are V8s. The generation started out in 1982 with two V8 choices. The LG4 was a 305 ci 4-barrel with 145 hp and the top engine was the L69, a 305 with “CrossFire Injection” making 165 hp. The latter was used on the Corvette, but with a 350 (5.7). It was essentially two throttle body injectors (TBI) on a cross-ram manifold. They looked awesome but didn’t make much power and were prone to drivability issues.

In 1985 Tuned Port Injection (TPI) arrived and it transformed the lowly 305. Horsepower jumped to 215 hp, drivability and most important to the corporate suits, fuel economy improved. TPI too was a great-looking system that made the engine look futuristic with its ‘bundle of snakes’ intake runners. At this point one could order any Camaro or Firebird of their choice with either a 5-speed manual or a 4-speed automatic. In 1987, for the first time a version of the 5.7 (350 ci) with TPI became available. These were almost a Corvette engine. The ‘Vette’s engine had aluminum heads and these had iron heads, but otherwise they were pretty close and made comparable power…if you ordered the right package.

The Achilles heal of the 3rd-gen F-bodies is that they’re so low to the ground that there isn’t a lot of room for exhaust plumbing. That’s why there was never a true dual exhaust system on any 3rd-gen F-body. They were all 2-into-1-into 2 setups. The two sides joined in a “Y” next to the rear of the engine on the passenger side, then they went through a cat next to the tranny, then a single pipe snaked its way down the driveshaft tunnel and over the rear axle, to a sideways muffler behind the axle. One pipe went in one side and two pipes came out, one on each side, that exited the back corners of the car. It was a restrictive system to say the least and it choked off the power. In standard form this rendered the 5.7 to making 230 hp. However, if you checked off the G92 package on the order sheet, you got a dual-cat exhaust system that still followed the same 2-into-1-into-2 path but flowed much better. With it, the 5.7 made 245 hp, the exact same output as the Corvette that year.

GM didn’t have a 5-speed manual transmission in their system that could handle the torque of the 5.7, so it was automatic-only. If you wanted a 5-speed you had to opt for the 5.0. At this point, there were two 305’s (5.0-liter), the LG4 with 4-barrel carb and making 150 hp and the LB9 with TPI making 215 hp. Then there was the L98 5.7 TPI making up to 245hp. This was the last year for carburetors. Starting in 1988 everything was fuel injected. TPI stayed the same on both the 5.0 and 5.7, but the carbureted base V8 was replaced by the LB8, a 5.0 with TBI (Throttle Body Injection) making 170 hp.

The Z/28 was the Camaro’s high-performance package right from the start and the Trans Am was Firebird’s. Both came with the same engine and transmission choices, and TPI V8s were only available on these models. Everything else got a V6 or the TBI 305.

The Z/28 package included a TBI 305 as standard (but had the option to go with TPI on a 5.0 or, from 1987 on, a 5.7), heavy duty suspension, bigger brakes, rear spoiler, special hood with faux louvered scoops, sport gauges, emblems, stripes, etc. The Trans Am was mechanically almost identical with some subtle difference in suspension and steering tuning. Chevy called their handling package 1LE and Pontiac called theirs WS6. As a general rule Pontiac lived up to its corporate position, one notch above Chevrolet. Their interiors were nicer, with richer fabrics and carpeting, with soft plastic shift knobs instead of hard plastic on the Chevy. The Firebird’s ashtray glided open on dampers while the Camaro ashtray snapped open like it was going to break off in your hand. The Firebird enjoyed the extravagance of hideaway headlights. Can you imagine how much that must have cost? Just to one-up Chevy?

In 1985 the Z/28 was selected to be the standard car for the IROC racing series. The International Race of Champions pits top drivers against one another in identical cars so that it becomes a battle of pure skill. So, Chevy made IROC-Zs an option on top of the 1985 and 1986 Z/28s. It added 16-inch IROC wheels, special suspension bits and IROC-Z graphics to the already well-equipped Z/28. So, during these two years you could order a Z/28 that was not an IROC. Or you could go with the Z/28 IROC-Zs and had both Z-28 emblems and IROC-Z decals on the doors. Starting in 1987, the Z/28 name was dropped and there were only IROC-Zs. 1987 was also the first year for the 5.7 and the first year for the convertible. There hadn’t been a convertible since 1969. The IROC series switched cars in 1990 and started using Dodge Daytonas so the IROC-Z went away and the Z/28 returned in 1991 and 1992.

Also in 1985, Pontiac launched their own special model. The GTA was intended to be a high-end luxo model of the Trans Am, sort of like the GTX was to the Road Runner. It came standard with the 5.7 TPI and had a premium interior with rich fabrics and leather in all the right places. The seats were fully articulated. They continued the GTA through the end of the 3rd-generation in 1992.

Airbags came in 1990, but only for the driver. Passenger-side bags would have to wait until Gen 4. In 1991 both sisters got a facelift. The Camaro’s consisted of a new ground effects apron with bigger front air dam and faux brake cooling scoops in front of each wheel. This was on all ’91-92 Camaros, not just Z/28s. IROCs had always gotten their own 16” IROC rims, but those were gone now. In their place was the 16” 25th Anniversary rim, to commemorate 25 years of Camaros. Technically that would have been 1992 only, but the ’91 got the wheels. All 1992 Camaros were called 25th Anniversary Editions, however there was an optional appearance package called the Heritage Package that included, among other things the new 16” 25th Anniversary wheels. However, they’d already been released in ’91 across the entire Camaro line, which now consisted of the RS and the Z/28.

Also in 1991, the Trans Am got an all new nose and a new look. It was sort of a love-itor- hate-it affair. I personally didn’t think it improved the looks. It was sort of snarky. Sales started out pretty strong in the first half of the 3rd-generation, averaging over 195,000 Camaros per year and 105,000 Firebirds. But by 1992 that number had fallen to 70,712 Camaros and 27,567 Firebirds.

The 4th-generation was right around the corner but wouldn’t offer much relief. The world was changing and the market that drove this segment just wasn’t there anymore, not like it once was, at least. The Baby Boomers who had been the core of their market in the beginning had grown older and more affluent, and were raising families. Minivans and SUVs gained in popularity during these years, and the F-bodies paid the price.

“Chevy’s Mark IV Big Block”

Chevrolet introduced their first modern V8 (they made a V8 back in 1917-1918) in 1955. Of course, we all know how that went. The Chevy Small Block V8, as it came to be called, started out as a humble 265 and grew all the way to 400 ci. It was and is one of the most successful and prolific car engines ever made, having powered nearly everything Chevy and later GM made for seven decades. 93 million were built (not including the modern LT- or LS-series)! 93 million small blocks. That’s one helluva record!

Starting out in 1955 with 265 cubic inches, it made 225 hp tops. Once the bugs were sorted out of the new design, it was quickly expanded to 283 ci in 1957 and horsepower also grew. Even fuel injection was added, a radical move for 1957, which stood out even more because it fostered the first American engine to make one horsepower-per-cubic inch of displacement, 283 hp from the 283 Fuelie. That was impressive. But by 1958, they’d slapped dual 4-barrels on it and made 290 hp.

But it wasn’t enough. Chrysler’s Hemi’s passed the 300 hp-mark long ago and now Ford’s new FE big block engine family arrived in 1958 with a 352 ci V8 making 300 hp and gobs more torque. The fun was over. While they could continually enlarge the small block, they needed a heavy duty big block like Ford and Chrysler, with strong internals and an advanced design.

Enter the W-series in 1958. Starting out as a 348 ci, it too was quickly blown out to 409 ci and became a legendary performance engine in its time. The Beach Boys even did a song about it in 1962. This was Chevy’s first attempt at a big block and it was successful to a point. But it’s limitations were quickly discovered. Strangely, Chevy had decided to machine the deck surface of the block (where the heads bolt to) at an angle, not square with the bore. This, combined with an oddly-shaped combustion chamber and piston crown was supposed to improve flow, cylinder-filling, and fuel burning. It was an interesting experiment and a bold move on Chevy’s part, but it had more flaws than advantages and probably stayed too long.

It was a great engine for Chevy’s full-size passenger car line and their trucks in milder form, and in the early 1960s its performance was considered exceptional. But, it was quickly being eclipsed by its competitors. They’d learned a lot of lessons with the Wseries, that could be applied to a whole new engine, a clean-sheet design.

By 1962, design work had started led by Chevy’s Chief Engineer, Bill Fisher, with heavy input from Zora Arkus-Duntov, the legend, and the Corvette Chief Engineer. Fisher wanted a great street engine that could easily be scaled up as needed, an advanced design that would be easy to produce, and Duntov wanted the Corvette to dominate racing and the street scene. The new engine made it’s debut at Daytona in 1963, dubbed “the Mystery Motor” because no one knew what it was. They were expecting the W-series 409. This new engine was unstoppable.

By 1964 early prototypes were enduring extensive dyno work and durability testing. And by mid-year 1965 they released the first Mark IV big block, the 396. Available in a wide variety of Chevrolets, the midsize Chevelle/Malibu, the full-size Impala line, Chevy Trucks, and the Corvette, the new 396 came in 3 flavors: The L35 with hydraulic lifters and a 10.25:1 compression ratio good for 325 hp; the L37 also with hydraulic lifters but a much hotter cam and making 375 hp (but was only available in the Chevelle SS396); and the L78 with solid lifters and a red-hot cam, rectangular-port heads and an 11.00:1 compression ratio with a whopping 425 hp!

This bold new design shared nothing with the W-series that came before it except its 4.84” bore spacing. It was designed from the start to be a heavily oversquare (big bore, short stroke, relatively speaking), large displacement, super-strong, expandable architecture. The tall deck height allowed for increases in stroke and the wide bore spacing left plenty of room for increases in bore. But the key to performance always comes down to breathing, and this massive engine would need lots of it. The heads are a masterpiece of flow optimization. The massive, heavy cast iron heads had huge intake and exhaust ports with straight paths in and out, and the large valves were arranged in the absolute best position to maximize efficiency. That placed the valves oblique to one another, not parallel on any plane. The intake valves point one way and the exhaust valves point in a completely different direction. They’re not far off from one another, but the difference is quite obvious. They’re called “porcupine heads”, and they were harder to produce than small block heads with all their valves lined up straight. But the added cost and complexity was worth it, because the new big block breathed and performed brilliantly, with enough room to expand by every measure.

And expand they did. In 1966 a new, larger version of the Mark IV big block was introduced with 427 ci, an engine that eclipsed anything that Ford had certainly, and even rivaled the mighty 426 Hemi. The 427 dominated racing from 1967 through 1970. The standard version (L36) had a single 4-barrel and made 390 hp. The L72 had solid lifters and a Tri-Power setup (three 2-barrel carbs) and made 425 hp, and these were the street motors. Chevy also built two wicked race motors rarely seen on the streets, although super-rare examples do exist.

The 1967-1969 L88 (RPO L88) used large rectangular-port heads, a 12.5:1 compression ratio, a radical solid-lifter cam, an 850 cfm Holley with no air cleaner, high-flow exhaust manifolds and 4-bolt mains all built on a special high nickel-iron their advertised horsepower was 430, but it was more like 550+ in the real world.

The 1969-only ZL1 (RPO ZL1) used an all-aluminum block and heads, cutting over 150 pounds, an even more aggressive solid-lifter cam, special lightweight pistons and rods, and dry-sump oiling. Otherwise it was the same internally as the L88. Chevy stated the horsepower at 430, the same as the L88, but in fact it was above 600.

Both engines are incredibly rare, having been made expressly for racing and never intended for street use. However, wily Chevy dealers back then figured out how to game the system by plugging the right option codes into the COPO (Central Office Production Order) system. They could get Novas, Chevelles and Camaros with 427s, including these crazy racing engines. Chevy went along with this because SCCA and NHRA rules required that a certain number be sold to the public for homologation.

Cars from Baldwin Motion and Yenko were sold new with financing and factory warranties. Most were intended for racing, but some made it onto the street. Among the rarest is the 1969 ZL1 COPO Camaro with the all-aluminum 427, just 69 were built. Today a genuine Yenko of any kind brings top money at auction.

1970 was a big year, many things seemed to turn on it. In 1970, GM dropped it’s decade-long ban on engines larger than 400 ci in their midsize cars. In 1970, the 396 got bumped to 402 ci with a slight increase in bore, but Chevy continued to call it a 396. And in 1970, the 427 got punched out to 454. The standard 454 (LS5) had a hydraulic cam and 10.25:1 compression, made 365 hp and was a $295 option. The top engine costs four times as much, at $1,221, but boy was it worth it!

Not including race car motors like the L88 or ZL1, the ultimate Chevy big block had to be the 1970 454 ci LS6. It was strong with 4-bolt mains, forged steel crank and rods, forged alloy pistons. It breathed well, with rectangular-port ‘open chamber’ heads (casting #3994028), 2.19” intake valves and 1.88” exhausts, an aluminum low-rise dual-plane intake manifold mounting a single Holley 4150 800 cfm 4-barrel carburetor with mechanical secondaries. And it made big power with an 11.25:1 compression ratio and a radical solid-lifter cam. Chevy claimed they made 450 hp at 5,600 rpm and 500 lb-ft of torque at 3,600 rpm. Big numbers to be sure, bigger even than those claimed by Chrysler for their much-vaunted 426 Hemi. But they were all unnaturally low. Most experts agree that the 1970 LS6 made well north of 500 hp at higher rpms than 5,600. Chevy didn’t want to alarm the insurance companies with such lofty claims, so they simply cut off their dyno tests at 5,600 rpm. But bigger power awaited up around 6,500.

Funny thing, though. This ultimate big block, this top dog muscle car motor, the pinnacle of V8 technology at the time was only available in the 1970 Chevelle SS454. Not Chevy’s full-size cars, and not even the Corvette. That’s unusual since Chevy always reserved its best performance engines for the Corvette first. But, for 1970 the only big block option for the Corvette was the LS5 454 which made 365 hp. The LS6 wouldn’t come to Corvette until 1971 but by then increasing smog regs dropped output to 425 hp. Only 188 were built.

1970 was the last good year, then the Malaise hit in 1971. The combination of all the new smog, gas mileage and safety regulations, the removal of lead from the gasoline and rising insurance costs was killing performance. GM went on a wholesale campaign to neuter all its engines in an effort to meet the new standards.

Big block options became limited, compression ratios fell, cams became milder, carburetors got smaller, tuning was dialed back and endless new gadgets began appearing on these already-choked off engines. And horsepower ratings dropped dramatically and continued to drop for years.

The last year for an optional big block was 1972 in Corvette, Camaro and Chevelle. The last year for Chevy’s full-size cars was 1976, by that time down to just 225 hp. From then on the Mark IV 454 big block soldiered on in Chevy and GMC trucks and SUVs through the first half of the 1991 model year.

That’s when the next generation of big blocks came out. The new Mark V was known as the Vortec 7400 and alongside Chevy’s venerable small block, and some 6-cylinders powered every full-size truck and SUV that GM made, until 1999. In 2000 Chevy punched its mighty big block out one more time to 496 ci, making it the Mark VI and named it the Vortec 8100. This 761-pound monster powered many of GM’s biggest trucks through 2010. From then on it was LS or diesel all the way. Well, until lately, now they’re putting turbo 4-cylinders in full-size trucks. It’s a travesty.

It would seem that the age of the big block has come and gone. None remain. Chrysler’s B and RB engine families (383, 413, 426, 440) died in 1972. Ford’s FE big block (352, 390, 427, 428) was gone by 1970, replaced by the 385-series big block (429, 460), itself gone by 1978 in cars and 1997 in trucks. Today’s modern V8s, Ford’s Coyote, Chrysler’s Gen 3 Hemi and GM’s LS/LT-series can make all the power and torque of the classic big blocks with less displacement, better fuel economy, cleaner emissions and 300 pounds less weight.

But Chevy’s amazing Mark IV big block lives on in racing of many different types. It’s still the most favored engine in drag racing (Hemi fans may argue this). And it’s very strong in the classic and custom car world. Classic Chevelles, Impalas, Camaros and Corvettes with big blocks from the factory get all the attention at shows and command top dollar in auction.

If you look at the lifespans of America’s other big blocks, the Chevrolet Mark IV has had the longest life, by far. Chevy’s own W-series lived from 1958 to 1965 (8 years). Ford’s FE big block lasted from 1958 to 1970 for cars and 1976 for trucks (19 years). Chrysler’s B and RB big blocks were around from 1959 through 1978 (20 years). Ford’s 385-series big block, the 429 and 460 went from 1968 through 1997 (30 years). Chevy’s big block was produced from 1965 through 2010 (46 years). No else even comes close. That’s how good an engine it was and is, what a great design it had from the start. And it’s still revered to this day.

For being billed as GM’s ‘bargain-priced brand’, the lowest in it’s ascending ladder of brands, Chevrolet really took the lead in performance, and not just at GM, but out there on the street. And up against some daunting competition from Chrysler and Ford, both strong on engineering. Chevrolet gambled with the Corvette, then stuck with it when it struggled, and endured low sales volumes because they knew it was important. Important to the Chevrolet brand and important to the world at large. Corvette is something special. It always has been. And as far as engines go, Chevy’s Mark IV big block is also something special. Powerful, indestructible, beautiful (if you can call a brute like that ‘beautiful’), truly one of the world’s great engines.

So good in fact that 15 years after they went missing in new cars and trucks, Chevrolet still sells big blocks as crate motors. And talk about expandable, you can buy brand new big blocks in sizes 427 ci, 454 ci, 502 ci, 572 ci and 632 ci. 632 cubic inches? From Chevy?! Holy cow!

So, why call it a Mark IV? The W-series 409 was considered the Mark I. The Mystery Motor that first appeared at Daytona in 1963 was the Mark II. The Mark III was a 1963 design study that would have changed bore centers, but was never produced. When the new engine went into production in 1965 it was called Mark IV. And what an engine!

“Camaro Z/28, the First Two Generations”

Following the very successful launch of the Ford Mustang in 1964 (as a 1965 model), GM took two full model years to launch a response in the form of their own pony cars, the 1967 Chevy Camaro and Pontiac Firebird. Both were spun off the same F-body platform, which was loosely based on the Nova platform. They were essentially almost the same cars with different sheetmetal skins, interiors, engines and minor tuning and setup differences.

Chevy couldn’t hope to outperform the red-hot Mustang in sales, but they could outperform it on the street and at the track. GM’s built-in advantage was that any engine they had would fit, whereas the Mustang was severely limited on engine choices because of its narrow engine bay. And both of GM’s ‘sister cars’ had high performance engine options and packages. Over at Pontiac, the Firebird could be optioned up to the Firebird Formula package which came with a 400 ci V8 and was their straight-line stoplight drag car, or the Trans Am, known for it’s great handling. Chevy did the same thing.

On the Camaro side the straight-line acceleration beast was the Camaro SS, available with the new 350 small block or the 396 big block. The 1967 Camaro SS was the first GM vehicle ever to get the new 350. And their great-handling track car was the Camaro Z/28.

Initially the Z/28 was intended purely as a limited-production homologation to qualify them for SCCA Trans Am racing. Homologation is where the governing body of a racing series requires the manufacturer to sell a certain number of the cars to the public to establish it as an actual ‘production car’. SCCA required 1,000 sales to qualify to race in the series. Just 602 Z/28s were built for 1967. How did they homologate it with less than the required 1,000 sales? Because Chevy did the same thing that Pontiac did with their Trans Am. They claimed that the Z/28 was simply an option package for the Camaro, meaning that every Camaro sold should count, and since they sold 220,906 Camaros in 1967, they passed.

The Z/28 dominated the 1968 and’69 Trans Am racing seasons, winning the Manufacturer’s and the Driver’s Championships both years with Mark Donohue driving. In ’68 he won 10 races and in ’69 he won 6 out of 7 races.

However, a genuine 1967-69 Z/28 is not an ideal street car. To race in the Trans Am series, engine displacement was limited to 5.0 liters (305 ci) so the standard 327 ci V8 couldn’t be used. Instead they used the block from a 327 with its 4.00-inch bore and dropped in a forged steel crank out of a 283 with it’s 3.00-inch stroke and this came out to 302 cubic inches, just below the limit. The new engine was named DZ302, some say to honor Zora Arkus-Duntov, the father of Chevy performance. This severely oversquare setup created an engine that loved to rev, but didn’t make much power at lower RPMs. On the track, running a full throttle all the time, that was perfect, but in stop and go traffic on the street, it sucked.

All 1st-generation Z/28s came exclusively with the M21 or M22 Muncie close-ratio 4-speed manual, and most didn’t have power steering. AC wasn’t even on the option sheet. These were meant to be stripped-down race cars and they weren’t easy to live with on a daily basis. All 1st-gen Z/28s could be ordered with the RS (Rally Sport) appearance package as an option. Their prominent feature were their hideaway headlights. As such, they were called Z/28 RS.

The 1968 Z/28 continued almost unchanged, other than a few styling touches over the ’67 model. Chevy began to realize they should be selling these cars in volume, not just homologating them. They sold 7,199 Z/28s in 1968 and 20,302 in 1969. Of course 1969 was a longer production year than normal, as problems with the 2nd-gen car delayed its release. The 1969 Camaro Z/28 is the most famous and popular of all Z/28s and probably all Camaros. You see them everywhere at car shows and at auctions. There are probably many more ‘clones’ or ‘tributes’ than genuine Z/28s, which is flattering. It’s easy to ‘create’ one. You start with a base Camaro, add some Z/28 emblems and stripes, black out the grille and add an appropriate engine. Some look very convincing. Make sure you’re looking at an authentic Z/28 if you’re paying Z/28 money for it. There’s nothing wrong with clones as long as the seller is honest about it and the price reflects it. In fact, they can be a good way to have a great car that you can actually take out, drive and enjoy. Genuine ’69 Z/28s are getting so valuable today that you’d have to be crazy to drive one on a regular basis. It’s estimated that over 25,000 clones of the ’69 Z/28 have been created, more even than Chevy built. To make sure you’re looking at a genuine Z/28 from the factory, check the VIN and the 5th digit must be a “G”. This is the engine code for the DZ302, and the only car that engine ever came in was the 1st generation Z/28.

The awesome DZ302 was rated at 290 hp, which is a joke. Most experts today agree it was more like 330-350 hp. This motor came with a Holley 780 cfm 4-barrel on a special high-flow aluminum intake manifold, a high-performance solid-lifter cam, highflow exhaust manifolds and dual exhaust, one of two close-ratio Muncie 4-speeds, the M21 or M22 “Rock Crusher”, a 12-bolt positraction rear end in either 3.73:1 or 4.10:1 ratios, heavy duty suspension, stiffer springs and shocks, larger front and rear antisway bars, quick ratio steering, power front disc brakes, 15” X 6” styled steel wheels with trim rings sporting F70-15 tires, a rear spoiler, and the Z/28’s famous stripes and emblems. Inside, it came with front bucket seats, a center console, floor-mounted Hurst shifter, a tachometer (mounted on either the steering column or the center console), and a Z/28 steering wheel.

The 1970 model year started late for Camaro and the new 2nd-generation car was a complete change from the 1st. While sharing the same F-body platform with the same 108-inch wheelbase as before, the new car was longer, benefitting the styling and proportions. Gone were the sharp corners, in their place was a smooth, aerodynamic shape with ‘European influences’. They looked great. The RS option package lost the hideaway headlights but gained a set of gorgeous split bumpers.

Homologation was no longer an issue so the 2nd-gen Z/28 got the new 350 ci LT1 with either a 4-speed Muncie or a 3-speed automatic. The new engine read like a checklist of what you do to make your V8 fast. 11.00:1 compression, solid lifter cam, big heads (2.02” intake valves), forged steel crank and rods, forged aluminum pistons, dual-plane high-rise aluminum intake manifold, Holley 780 cfm 4-barrel with mechanical secondaries. It produced 360 hp at a lofty 6,000 rpm, it had torque down low and it made big power on the high end. The big 350 liked to rev. The chassis itself had been structurally reinforced so the car handled better and felt more solid. Of course, Pontiac was working on the Firebird, and the Trans Am. They had their own family of engines though. Back then, Chevy’s got Chevy engines and Pontiacs got Pontiac engines.

The new 2nd-gen 1970 Z/28 was a fantastic car, performance-wise. They were fast and they handled incredibly well, partially due to their low center of gravity. These were low cars which made them harder to get in and out of, and left little room for exhaust plumbing. That’s why the Corvette version of the 1970 LT1 made 370 hp. But, just as things were getting interesting the Malaise hit in 1971. The combination of new smog, fuel economy and safety regulations, lead being removed from the fuel and rising insurance costs were killing performance. GM started neutering all its engines to try to meet the new standards. Big block options became limited and soon went away, compression ratios fell, cams became milder, carbs got smaller, tuning was dialed back and an endless array of weird new gadgets was appearing on these already struggling engines. By 1971, output on the LT1 dropped to 330 hp and by 1972 it was down to 255 hp (net). It got so bad that there was no point in having a high-performance option like the LT1, so the engine was dropped for the 1973 model year.

The new ‘5 mph bumper law’ forced Chevy to change the face of all of its cars, Camaro included. The new law required that the front bumper must be able to sustain a 5 mph collision with no visible damage. This required mounting the strengthened bumper on spring-loaded shocks and providing the space they would need when they compressed. Some 5 mph bumpers looked like park benches. The 1973 model year was when it was supposed to take effect, but Chevy cleverly found a way to reinforce the front ends of the ’73 Camaro to buy another year. But starting in 1974 they got big, ugly bumpers. In 1975 the top engine for the Z/28 was the L48 350 making a wheezing 155 hp. It got so bad that Chevy was too embarrassed to produce a Z/28 in the 1976 model year, so they just passed it over. There are no 1976 Z/28s.

The Z’ was back in 1977 with the L48 now making 185 hp. That’s more like it. Advances in technology were starting to show. The Camaro got it’s second facelift in 1978. The first one was in 1974 when they got the ugly bumpers. The new face was quite attractive, with a molded plastic skin hiding all the bumper stuff. They decked the ’78-81 Zs out with a teardrop-shaped, almost-NACA faux hood scoop and louvered faux heat extractor vents in the front fenders along with a rear spoiler, and of course the obligatory stripe package which by now was getting quite garish. It was the perfect look for the times, and it was a handsome car. They came with ‘styled steel wheels or a 15” aluminum turbine-style ‘mag’ with 30 spokes.

The new styling paid off. Sales jumped to 272,631 Camaros in model year 1978 and 24,600 of them were Z/28s. That’s the most Z/28s ever! By the end of the 2nd generation in 1981, the L48 in the Z/28 was making 190 hp.

The 70s were behind us and with it, the Malaise. Technology was finally catching up and enabling the smart people in Detroit to make cars fast again, while meeting all the federal mandates. The 3rd-generation would exemplify this, in spades! The new car would advance to art and science in its structure, aerodynamics, styling and powertrains. But, that’s another story for another day. The Camaro and the Z/28 have lived on for seven generations, this was just the first two. Yet by this time the Z/28 had staked out its place in automotive history.

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