Car magazines were my friends when I was a young teenager in the late ’60s. While I was crazy about Corvettes, there were no road racing tracks, only a drag strip close to where I lived in Collingswood, New Jersey. So, if I wanted some racing action, the drags was it; which was fine by me because tire-burning muscle cars regularly roamed the streets of our town, and were SO COOL.
Zora and his brother, Yura were making and selling their Ardun hemi-head conversion kits for flat-head Fords in the early 1950s.
Hi-Performance CARS, Popular Hot Rodding, Car Craft, Car and Driver, Car Life, and Hot Rod Magazine were my favorite flavors for fun reading. But somehow, the December 1967 issue of Hot Rod got past me, as I did not see that issue until way after eBay sellers started selling them 20 years ago. Recently I picked up a copy to add to my Corvette library.
The BIG SPLASH is the cover! There was Zora on the cover of Hot Rod, in a corporate gray suit, white shirt, a narrow black tie, and all smiles; but then again, Zora never knew a camera he didn’t like. And why wouldn’t he have been a happy guy, sitting there with four exotic experimental Chevrolet engines; single-overhead cam heads, and double-overhead cam heads with fuel injection systems of different configurations. Duntov even pushed to offer a SOHC kit for small-block Chevy engines via the Chevrolet Parts Catalog! Imagine that under the hood of your Vette!
Hot Rod’s editor, Jim McFarland got the plum assignment to go to Detroit with a recorder and interview Duntov about “some” of the experimental engines Chevrolet engineers were playing with. After the sixth paragraph, McFarland turns over the mic to Zora to take it from there. Duntov was very exacting and articulate in explaining everything he was allowed to talk about. Zora may have been the ultimate corporate misfit in his time, but he knew when to stop talking.
Here’s Zora and Jim McFarland many years after the famous Hot Rod Magazine “Inside Chevy’s Secret Engines!” December 1967 cover story.
The article is a fascinating peek inside the thinking of Chevrolet performance engineers, circa 1967. Enjoy! – Scott
Before the 1969 427 ZL1, there was the All-Aluminum 377 Small-block Chevy!
Dateline: 5-7-21, This story by K. Scott Teeters was first published in the October 2019 issue of VETTE magazine – In the early 1960s, an aluminum performance engine was as exotic as fuel injection, independent suspension, and four-wheel disc brakes. The first mention of an all-aluminum engine for a Corvette was in Zora Arkus-Duntov’s proposal outline for the Q-Corvette in 1957. Ed Cole was Chevrolet chief engineer from 1952 to 1956 and was the lead engineer in the design and development of the small-block Chevy.
The Wintersteen L88 Grand Sport #002 resides at the Simeone Museum in Philadelphia, PA. Part of the collection includes the hand-made #002 Roadster replica body and one of the all-aluminum 377 SBC engines that Dr. Simeone purchased from Jim Jeager. The replica body is mounted to a chassis buck with an interior.
Cole was a mechanical engineering visionary. After he became Chevrolet’s general manager in 1956, Cole announced his 1960 Q-Chevrolet concept that would put a transaxle into every car to improve traction and handling and eliminate the transmission hump that would open up the interior. Cole’s plan included the Corvette.
Even before going to work for Chevrolet, all Duntov wanted to do was to build racecars. Based on his racing knowledge, Duntov’s Q-Corvette was spectacular and included; a four-speed transaxle, four-wheel independent suspension, four-wheel disc brakes, and an all-aluminum fuel injected 283 engine. Duntov is usually credited with the all-aluminum small-block Chevy, a deeper look tells a slightly different beginning.
The design parameters of Cole’s SBC were that the engine should be; small, lightweight, simple, and inexpensive. Cole reasoned that an aluminum version of the SBC using a new aluminum-silicone alloy would be obviously lighter and probably less expensive to make. To keep costs down, there would be no valve seat inserts, no pressed-in valve guide inserts, or cylinder liners. But sometimes a simple idea turns out to not be so simple.
Problems started right from the beginning. The complex molds used sand cores and the completed castings required extensive machining. Sand-cast aluminum is high in porosity and low in density. During machining, cavities would open up in the castings, causing a high rejection rate, which drove up the cost.
Another indication that this is likely to be one of the Nassau Invasion 377s is the chrome stamped steel valve covers. Photos in the “Corvette Grand Sport” book by Paddock and Friedman from the race show the same valve covers.
Aluminum pistons on aluminum bores were hard to lubricate and would scuff the bores. Between the strength of materials and the casting challenges, pouring aluminum into molds designed for cast iron wasn’t going to work for mass production.
Weber carbs were THE hot setup in the 1960s before fuel injection became more efficient. The 377 used four massive 58mm side-draft carburetors. The “EW” on the float chamber cover stands for Edoardo Weber, the founder, and inventor of the Weber carburetor.
A few aluminum engines were completed. Duntov installed one in his CERV-I car in 1959, but the valves would freeze to the guides when the temperature went low. Mickey Thompson got an aluminum engine for an Indy car project and bored the cylinders to installed steel sleeves to reduce the C.I.D. to the Indy limit of 255-C.I.D.
Note the non-stock location of the alternator. This was to slightly lower the car’s center of gravity.
Roger Penske had TRACO modestly build an aluminum SBC to just 300-horsepower for his Cooper Monaco. When TRACO was done, the engine weighed just 350-pounds; the lightest of all the aluminum SBCs.
Forensic evidence gleaned from the book, “Corvette Grand Sport” by Paddock and Friedman indicates that based on the shape of the collector on the headers, this was most likely one of the engines used during the Nassau assault in 1963.
The original SBC was never designed to be cast in aluminum. So when exact copies were cast in aluminum, the basic weaknesses of the original design were obvious. In 1960 some Corvette brochures offered 275 and 315-horsepower fuel injection engines with aluminum heads but were canceled early in production due to breakage. Briggs Cunningham was to be given several sets of aluminum heads for his Corvette Le Mans assault, but none were installed.
When Duntov started planning his Lightweight Sting Rays in early 1962 to battle Shelby’s Cobras, the SBC had 327-cubic-inches. Duntov insisted on an all-aluminum 327, reasoning that the heavy-duty parts from the L84 Fuelie would be more than enough for his racing engine. Unlike the previous aluminum engines, steel cylinder liners were pressed into the block. After each block was machined, it was water-tested for leaks. If leaks couldn’t be fixed with welding they were scrapped.
The most significant change to the basic block was that the main bearing webs were thicker and four-bolt main bearing caps were used. The earlier aluminum SBCs were not delivering any significant power increases, so it was decided that more cubic inches were needed. A 4.00-inch stroke yielded 402-cubic-inches. However, experimentation showed that the engine was happier with a 3.75-inch stroke that yielded 377-cubic-inches. Notches had to be made into the insides of the block for connecting rod clearance.
Numerous cylinder head designs were considered. The wildest was a hemi head design with two spark plugs per cylinder. The hemispherical combustion chamber allowed for larger 2.20-inch intake and 1.72 exhaust valves. The intake system was a Rochester constant-flow fuel-injection unit. This was Duntov’s preferred engine for his Lightweight but never was developed or tested. Engineers expected 600-horsepower from the 402-cubic-inch configuration.
The Mark II big-block with its unique “porcupine” semi-hemi heads was in development, so engineers designed and cast similar sets of aluminum heads for the SBC. Initial tests showed that they did not flow as well as the standard wedge combustion chamber heads, so the concept was dropped. If the heads had been developed they could have been a game-changer and made it into production cars.
Twelve aluminum 377 blocks were successfully machined and designated “A” to “L”. WhenJohn Mecum took delivery of three Grand Sport Corvettes as part of his Nassau invasion, the cars had aluminum 377s with four 58-mm Webers. After the Grand Sports stomped the Cobras at Nassau, the cars were bought and sold at a brisk pace.
Engineers learned that the aluminum 377s were good for short races, such as Nassau, but not durable for long races, such as Sebring. When Penske raced Grand Sport #005 at Sebring in 1964, his car was powered by a steel version of the 377 and performed very well.
Several of the engines were sent to Jim Hall and installed into his Chaparrals. Hall was instructed to install the engines and not to change anything except for timing and settings for the Webers. The engines were plugged in, raced, and returned to Chevrolet for evaluation.
The inscription of the transmission is unusual and indicates that it was likely to have been a specially built unit. “W.O.26310” could have meant “Work Order”. “TRANS #7-B” could have meant the second rebuild of transmission #7. Also note that the bolts on the case side plate are aircraft safety wired. A special team at Chevrolet built all of the 377 engines, the safety wiring was likely a deterrent to tampering.
As the engines were raced, eventually nearly everything either failed or upon examination was soon to fail. For instance, when one engine threw a rod, engineers used a new process for making rods called, Vacuum-Induction Melt steel to insure no impurities in the raw forging. When bolts were magnafluxed and showed signs of stress, all bolts were then over-designed. Rocker-arm lube was another issue and there were electrical problems with the early-transistorized regulators and ignition amplifiers.
Note the serial number on the back of the block casting, “0240983” and the casting date, “8-20-63”. This “could” have been one of the engines used in the 1963 Nassau assault in early December 1963 that stomped on the Cobras.
Exhaust headers were showing signs of cracking at the ports due to metallurgical problems. This was fixed by using a different welding process. Camshaft gears were failing when dry-sump oil systems were installed. Excessive stress and wear on the camshaft drive gear caused the distributor to retard the timing; causing a drop-off in power.
Privateers raced all of the Grand Sports and many changes were made to the cars. One of the previous owners of the Simeone 377 built this expanded capacity oil pan. Original versions of the engines used as many stock performance parts as possible
The perceived advantage of the all-aluminum SBC was weight; the complete engine weighed 150-pounds less than a cast iron version, however, the aluminum engines didn’t make quite as much power. Because durability was such a serious issue, in the early years, development work went into durability.
Eventually, the aluminum SBC reached optimum development, priced itself out of racing, and didn’t contribute any parts that went into production engines. Close to the end, there was talk of an overhead-cam kit for the SBC, but no action was taken. The amount of money spent on the program was an accounting nightmare for sure. At best, all the problem-solving saved years of development time for the all-aluminum Can-Am block and the ZL1. In a sense, the all-aluminum SBC was a prehistoric ZL1, domed by the basic “bread and butter” design of the original SBC. – Scott
Reproductions of this post’s lead illustration of the All-Aluminum 377 Small-Block Chevy and the Grand Sport #005 are available as 11″ x 17″ prints, signed and numbered by the artist, CLICK HERE!
And for fans of the 1963 Grand Sport Corvette, we have LOTS of Grand Sport Corvette prints CLICK HERE!
A Look Back At An Inexpensive Option That Delivered a Little Extra Grunt and A Lot of BARK
Note: This article was first published in the December 2013 issue of Vette Vues. Subscribe to Vette Vues HERE! –Corvettes enjoyed a banner year in ‘08. When no one was looking, GM unleashed the latest variation of the LS generation small-block Chevrolet engine, the LS3. This latest edition of the highly successful LS series of GM engines is only 12-cubic-inches larger than the LS2, but uses the Z06-style valves and port design that features larger and straighter intake ports, nine-percent larger valves, and a five-percent higher cam lift. For what wasn’t much of a stretch, the LS3 netted out an extra 30-horsepower for the base model Corvette, which added up to a whopping 430-horsepower for the base Corvette! But a close look down the ‘08 Corvette option list shows a little item called, “Dual Mode Exhaust System” (RPO NPP) for $1,195. This was the first time since 1969 that Corvette buyers had a factory exhaust system option.
This version of Corvette factory side pipes were available from 1965 to 1967
You could call it the Trickle-Down Horsepower Theory from the high-performance Z06. The Dual Mode option functions the same as the Z06 version. The outlet valves are vacuum-actuated to open during what Chevrolet calls, “high-load operation.” (That’s GM-speak for “get’n on it!”) While the Z06 version has 3-inch diameter exhaust pipes, the LS3 version uses 2-1/2-inch pipes. So, how much extra grunt do you get for your $1,195? The system adds 6-horsepower and 4-ft/lb of torque. While those numbers aren’t terribly impressive, the exhaust note certainly is. Of the 35,301 Corvettes sold in ‘08, 13,454 (38.1%) were equipped with the new system. That’s pretty cool, considering that’s only $199.16 per horsepower unit and $298.75 per torque unit, but we won’t quibble over numbers. After all, the system sounds great!
As these side pipes got older, they got louder.
It all got me to thinking about those infamous, barking side-pipes that were offered from ‘65 to ‘67, and slightly milder ‘69 side-pipes that made even the 300-HP small-block sound as ominous as a junkyard dog. Two unique designs were offered back then. Beginning in ‘63, as part of the overall Z06 package, was the $37.70 N11 option, the Off-Road Exhaust System, which included low-restriction, under the car mufflers and 2-1/2-inch exhaust pipes. This option was available through to ‘68 and was officially listed as “off-road.” (That’s GM-speak for “race track”, is in, racing.) The N14 Side-mount Exhaust System was another animal altogether. The system begins at the end of the exhaust manifold flange with the typical 90-degree bend.
Side pipes were not available on the new 1968 Corvette but were brought back for 1969 only. The side pipe setup was available through Chevrolet Parts Department for many years after 1969.
But instead of bending towards the back of the car, the bends were directed towards the sides of the car. After a short distance of about 12-inches or so, there was a gentle bend of approximately 118-degrees that leads to a long, straight tube that passed as a “muffler.” The “muffler” portion that ran along the side rocker panel had small crimps that created little internal baffles – and not much baffle at that.
Since Chevrolet didn’t want to burn the ankles of their Corvette customers and passengers, a set of beautifully styled, aluminum covers were designed. Each cover featured five horizontal ribs, with five sets of vertical blacked-out indentations between the ribs. The standard side rocker panel was replaced with a narrow polished aluminum rib that was mounted over the top of the covers. These hid the attachment screws that held the side covers. At the end of the piece of long, chambered tube was a downward-pointing chrome exhaust tip. And here’s the kicker… the Side-Mounted Exhaust System cost was only $131.65 in 1965! Plus, the system looked fantastic! Talk about “muscle.” Side pipes not only made ‘65 to ‘67 Corvettes look serious, they sounded serious!
The C3 side pipes look great on this black 1980-1982 model. Owners could not do this until the car reached “antique” status and was no longer subjected to emissions testing. In the side pipe system, there was no capacity for catalytic converters.
But as good-looking and inexpensive as they were, by the numbers, it wasn’t a terribly popular option. Only around 10-percent of all ‘65 to ‘67 Corvettes were optioned with the system. When the new Mako Shark II-inspired C3 Corvette came out in ‘68, the side-pipes weren’t on the options list. It was said that GM’s VP of Styling, Bill Mitchell, didn’t want to distract from the new shape with side-mounted exhausts. That may or may not be correct. It wasn’t that Mitchell was opposed to loud, side-mounted exhausts – nearly every concept and show car that came out of his studio had side-pipes as standard equipment. Considering what a nightmare it was getting the new Mako Shark II design out as a ‘68 model, perhaps there just wasn’t time for side-pipes.
This is Kevin Mackay’s “see-through” 1969 427 L88 Corvette. These mufflers were more like real mufflers, as they were not chambered pipe, like the 1965-1967 side pipes.
When the ‘69 Corvettes came out, side-pipe fans rejoiced over the return of the barking pipes. Only the new version didn’t bark as much. While the new pipes bolted on and functioned like their predecessors, the minimalist chambered pipe was replaced with a for-real muffler. However, the covers were beautifully styled to fit the unique shape of the Corvette’s side rocker panel.
A few specialty performance builders, such as Joel Rosen of Baldwin-Motion fame, installed the ‘65 – ‘67 units on his ‘68 and a few ‘69 Phase III Corvettes. While they didn’t fit exactly right, they still looked great. Rosen also added the first generation side-pipes and covers to his Phase III Camaros, Novas, Chevelles, and Biscayne supercars, although due to the short Corvette wheelbase, the system was less aesthetically successful than the C3 Corvette application.
During the 1970s, Hooker Header side pipes on Corvettes were quite common and helped un-cork whatever engine they were put on. This is Craig Cardwell’s 1970 LT-1 and was a LOUD beast!
So aside from the barking exhaust note and added bragging rights, what did the side-pipe exhaust system do for the car’s performance? Unlike the C6 Dual Mode Exhaust system, the old side pipes were never promoted to increase horsepower at all, or at least, they were never officially tested and certified. Of course, the only way to really answer that question would be to rear-wheel horsepower test, say a 427/435 427 ‘67 Corvette with and without the side-mounted exhausts. A lot of work just to find some numbers.
Craig Cardwell bought his 1970 LT-1 new and had the dealer install the side pipes.
So, I took the question to two genuine experts – veteran Corvette racer, Dick Guldstrand and Mike Cederstrom, owner of Sweet Thunder Chambered Exhaust Systems, in Cadillac, Michigan. Since Guldstrand has spent thousands of hours building and racing Corvettes for over 50 years, I thought Goldie might know how much horsepower the side-pipes were worth. Dick’s answer was somewhat surprising. “Those old chambered pipes did improve the engine’s performance, but not much. But then again, almost anything you did was an improvement over the stock system. The ram horn manifolds were pretty good, but nothing like big tube headers with proper phasing and the scavenger effect. But they sure sounded good!”
My conversation with Guldstrand was very historical. According to Mike, GM first started using the low-restriction chambered pipes as part of the ‘61 Oldsmobile Starfire performance package and standard equipment on the ‘64 – ‘65 models. But since the pipes were mounted under the cars and not on the sides, hardly anyone took notice. Meanwhile, over at Chevrolet, with the new big-block 396 engine coming out in ‘65 and the L84 Fuelies were making their last appearance, the Corvette designers wanted a little something extra and got approval to offer the chambered-pipe Off-Road Exhausts optional on all model Corvettes.
The chambered pipes have distinctive “crimps” on the exterior. Inside of each side-pipe is an inner 1-3/4” inner baffle tube with hundreds of small perforations. The crimps on the exterior are there to create the chambered sections, these are specific sizes that combined with the special perforations on the inner baffle tube. These two factors are what they used to help control different exhaust sounds. The “muffling” effect comes from all of those tiny perforations, which burn off after a few years of regular use. With only a 1-3/4” inner baffle tube, you can see why some call the side-pipes “chokers” and why Guldstrand commented that they helped a little, but not much.
The Sweet Thunder Company started making true factory-style, replacement chambered side pipes for Corvettes in the late 1990s. Not the crimps on the outer shell of the side pipes. All the crimps do is hold the inner pipe.
An educated guess might be close to what the new Dual Mode Exhaust System is worth – around 6-horsepower. Had the inner perforated tubes been in the neighborhood of 2-1/2-inches, horsepower increases would have been more substantial. “Why” the 1-3/4-inch inner tubes were chosen is anyone’s guess. Design engineers may have felt that was “enough.” Or perhaps larger diameter inner pipes were experimented with and were determined to be excessively loud. Within my extensive library of Corvette history books, I have never read of an accounting of side-pipe development. It is widely believed that mid-year Corvettes equipped with factory RPO N11 – the “Off-Road Exhaust System” consisting of a pair of GM “Hi-Flow” mufflers in the stock 2-1/2-inch exhaust system would out-perform side-pipes.
See the small perforations? They act like little sound scoops. That’s all that does any kind of muffling. The little perforation burn off after a few years, leaving an owner with an extra loud Corvette! I know, I had one that everyone complained about. “Your car is SO LOUD!”
Of course, side-pipes of one kind or another had been showing up on racing, experimental, and show car Corvettes since earliest Fuelie racers in ‘57 and the stunning Corvette SS racer. Many of Bill Mitchell’s important show and concept cars wore their exhausts on the sides from the ‘59 XP-700 dream car to numerous modified production-based show cars, as well as his Mako Shark I and Manta Ray cars. The Mako Shark I had exposed header pipes protruding from the sides of the fenders that blended into a collector fitted to a decorative, finned muffled cover. While these setups looked dreamy as show cars, exposed header pipes on a production car would never happen. But they did help pave the way for the tamer but deliciously loud chambered side pipes. Until steel tube headers became common, most racing Corvettes used the stock ram horn cast-iron manifolds and would either have a 2-1/2-inch diameter open pipe that exited just in front of the rear wheel or ran along the side rocker. This setup was obviously considered “open” exhaust and was completely illegal for the street.
Not that the factory optional chambered exhaust didn’t create a few problems with young Corvette owners, such as myself. Several inspection officers at my local DMV threatened to not pass my ‘65 Coupe with factory side-pipes because they didn’t like loud cars. I always passed… barely. Once I was told that if I came back next year with THAT CAR, it would DEFINITELY not pass! It wasn’t until my conversation with Sweet Thunder Mike that I learned why my ‘65 Coupe was so loud. Mike asked, “Were those original pipes?” To the best of my knowledge, my car came from the factory that way. They certainly weren’t “header” side-pipes. When I owned the car, it was 10 years old. Mike said, “That’s why. Those little perforations that were stamped into the very thin aluminized steel, didn’t last that long. The whole inner tube would just rot away. You were running nearly straight open exhausts!” he laughed.
I shared with Mike that my girlfriend at the time once said to me, “Your car is really cool, but it’s deafening!” Of course, it didn’t keep her from wanting to drive it from time to time. Once I thundered by a fellow in a 356 Porsche. As we were approaching a traffic light, I could see that he was quite agitated and was yelling at me, “I only got FOUR CYLINDERS, MAN! Four cylinders!!!” I thought, “Well, don’t complain to me!” So I pushed the clutch in and barked the side-pipes for good measure. Another time I passed a coworker friend on the way to work in a, shall we say, ‘spirited fashion” at around 6,000 rpm in second gear. Later in the office, my friend came over to my drawing board and said, “That car of yours is SO FRICK’N LOUD, I could feel the side windows in my Camaro rattling!”
Chambered exhaust systems eventually found their way into Camaro, Chevelle, and dealer-installed AMX cars. Usually, these systems ran under the cars to not draw too much attention. Former VETTE editor and founder Marty Schorr had a tricked out, black 390 Javelin with a set of ‘65-’67 Corvette side-pipes and covers. And what can only be considered a true anomaly was that a small handful of new Corvette buyers opted to have their new Corvettes equipped with dealer-installed Hooker Header side-pipes.
While repro side-pipes have been available for some time now, the guys at Sweet Thunder have invested a lot of time and energy into the reproduction of these new side-pipes with the correct sound. For more information and photos, visit Sweet-Thunder.com. Mike and his team also make chambered exhaust systems for the new 2010 Berger Chevrolet Super Camaros, as well as chambered exhaust systems for several other cars.
So, will side pipes ever come back as a production option for Corvettes? The short answer is, “No!” And many would ask, “Why would anyone want them?” After all, strictly “by the numbers” when offered, side-pipe-equipped Corvettes only accounted for 10-to-11-percent of new Corvettes. However, the side-pipe systems were available for many years through your local Chevrolet Parts Department, to be self-installed by owners. For several decades, ‘75 and newer C3 Corvettes that were equipped with catalytic converters could not have side-pipes and pass inspection. However, now that all of the C3 Corvettes are well over 25 years old and are considered “historic” cars, there’s a lot more leeway.
And what about C4 Corvettes you ask? The folks from Power Effects® obviously have a passion for side-pipes. What’s surprising about their Side Effects® system is that it’s actually a Cat-Back design. The factory catalytic converters remain in place. Just south of the catalytic converter is an aluminum splitter that makes a 90-degree bend to the right and left sides. The splitter is located in alignment with the final exhaust exit. The exhaust weldments bolt to the splitter, then make a 90-degree bend forward and bolt to the sound chamber that captures excess sound. Exhaust gas is then allowed to escape out the exhaust tips in front of the rear wheels.
There is a built-in heat shield attached to the weldment which keeps the composite side panels cool to the touch.
These panels can be painted to match the car’s body color or even custom painted, as seen in our photo sample. The system is available in two sound modes; “Sport” has a deep, throaty tone while “Touring” is a little quieter. Unlike the old factory side-pipes, this system has been dyno tested. L98-powered C4 cars can expect an additional 23-HP while LT1 and LT4 cars can expect a 10-HP gain. For C4 owners, this is an attractive way to personalize your machine. You can review their entire line of performance exhaust systems at PowerEffects.com.
With the introduction of the C5 Corvettes, design parameters were changed to make the new Corvette more of a GT, or Grand Touring machine. Then Corvette chief engineer, Dave Hill, brought his considerable experience working on Cadillacs to the Corvette line. Corvettes had a long history of quality issues and Hill wanted to make sure that owning a new Corvette wouldn’t be a headache. After the C5 was introduced, Hill’s team went on a hunt to eliminate as much excess noise from the cars as they could afford, but at the same time, not lose the car’s performance character. Hill explained that the C5 was the kind of car you could drive for 500 miles and feel good when you arrived at your destination. When he was outlining the parameters for the C6, he determined that after driving 500 miles in a C6 Corvette, the driver would feel GREAT! Obviously, droning side pipes wouldn’t fit into the equation.
The other factor in the demise of side-mounted exhausts was advances in exhaust systems in general. The biggest being the introduction of crossover and H-pipes. Besides emissions, the biggest factor has been noise restrictions on new cars. In order to be certified for production, carmakers must design the cars so that they pass decibel standards in a variety of conditions from various distances. The Corvette’s Dual Mode option is an interesting way to get around those standards because the solenoids only open the flaps during “high load” conditions. You could call the new system, “Bark On-Demand.” Considering that the C6 Corvette is more GT car than ever, the new setup is truly having your cake and eating it too. Well done, C
“I vant one of dez for Corvette!” – Zora Arkus-Duntov
Dateline: 12.24.18: Main photo from Hemmings.com – Okay, that’s probably not an “exact” quote for Duntov, but I’m sure that when he found out how much horsepower and torque the new Mark IV big-block made, he said something to that effect.
The Mark IV big-block engine was intended to be a replacement engine for the W-Series 348/407/427 truck engine. But very quickly in the development phase it was discovered that the engine was a torque monster.
When released in spring of 1965 in the Corvette as the 396/425 L78 for only $292, it was obvious that it was easier to make big horsepower and torque with the new big-block to the more exotic and expensive ($538) L84 Fuelie. The rest is history.
Hemmings Daily just posted an in-depth look into another piece of Corvette history that you can check out, HERE.
Photo: SuperChevy.com
To splash their latest in engine development at the New York World’s Fair, Chevrolet had on hand an animated cut-away display of the new engine, plus an animated See-Thur 1965 Corvette Coupe, PLUS a stunning factory custom Corvette.
Photo: Mike Yager / Ed Baumgarten
After all the years of building dynamic Motorama cars, the cut-away 396 big-block, cut-away Corvette, and custom Corvette was a delightful piece of cake for Chevrolet. – Scott
PS – Here’s a rare, in-living color look at the “GM Futurama” at the 1964-1965 New York World’s Fair. “The Future” had ARRIVED!
The BIG attraction at the New York World’s Fair was the Futurama Ride. It was a LONG wait to get in!
1990 ZR-1 Corvette – Finally! A Dedicated “Performance” Model Corvette
Dateline: 8.11.17 – Photos: GM Archives, Michael Beal, Illustrations: K. Scott Teeters –There’s an unwritten, unofficial “Law of the Jungle” that basically states, “If you are at the top of the food chain, you might not be there for long.” Such was the case for the C4 ZR-1 Corvette, for a little while. The C4 ZR-1 had a six-year production run with only 7,018 units produced. The ZR-1’s head-exploding price was the biggest limiting factor. The crummy economy in the early ‘90s didn’t help, and the much-rumored, all-new C5 no doubt was a drag on the ZR-1’s sales. And then there was also that pesky Dodge Viper. The 427 Cobra’s “Marley’s Ghost” was obvious, only this time disguised as a Dodge, While armchair quarterbacking is easy and hindsight is 20/20, it is worth asking the question, why wasn’t such an awesome car more successful? “Timing” aside, the ZR-1’s aesthetics was a big factor. Stated simply: When viewed by itself, the C4 ZR-1s look like “regular” Corvettes. As an illustrator and stylist, I find it astonishing that Chevrolet would have done this, after all the engineering work that went into the ZR-1. The body panels from the doors all the way back to the rear bumper cover, are unique to the ZR-1 – made wider to cover the widest tires put under a factory-built Corvette body, to that point. This means that the panels had to be redesigned. But rather than make them visually unique, the Corvette stylists were commanded to imitate the basic design of the standard Corvette, with one exception Continue reading “
The Story of the ZR-1 Corvette – C4 1990-1991 ZR-1 Corvette: Part 2 of 4″ →
George Haddad’s Stunning 1969 ZL-1 427 Corvette – With some personal touches!
Dateline: 7.6.17 (VIDEOS AT THE BOTTOM!) (This story was first published in the January 2016 issue of Vette Vues Magazine).
To understand the importance and uniqueness of George Haddad’s 1969 ZL-1 Corvette, we have to get into the “Vette Vues Time Machine” and go back to late 1968. The December 1968 issue of Hot Rod Magazine hit the newsstands like a thunder clap, with an obviously all-aluminum big-block 427 Corvette engine wearing bright yellow tube headers. It looked like Chevrolet finally had an ace trump card. The 427 ZL-1 was the ultimate “pie-in-the-sky” Corvette setup – big-block horsepower and torque – with the weight of an iron small-block! Duntov was a happy man because his dream of an all-aluminum engine for the Corvette went all the way back to the 1957 Q-Corvette concept that not only called for a fuel-injected all-aluminum small-block engine, but a trans-axle! (Sounds like a C5, doesn’t it?)
Duntov and his team tried casting SBC engines in aluminum, but there was a serious “strength of materials” issue that was never successfully worked out. The SBC was simply not strong enough when made in aluminum. A small batch of all-aluminum 377 engines were developed for the Grand Sport project that were powerful and light, but just wouldn’t hold together in competition. The prospect of an engine lighter than a regular SBC was deliciously tantalizing. So when the replacement for the 348/409/427 W-series (truck) engine, (the Mark IV) was being designed, an aluminum version was an obvious next step because the Mark IV was inherently a more stout structure. The story of the production ZL-1 Corvettes is a long and complex one that we won’t try unraveling here, except to say that a batch of seven cars were built in early September 1969. The cars that “rolled off the St. Louis assembly line” were full-out RPO-L88 cars. The RPO-ZL-1 aluminum block was an option that was only available on an L88 engine. In other words, the ZL-1 was identical to the L88, except it had an aluminum block – making it 100-pounds lighter than the L88 Corvette, something that only racers would even notice. Continue reading “
George Haddad’s Factory-Style 1969 427 ZL-1 Corvette” →
Dateline: 1.19.17 –C6 Z06 LS7 and C7 Z06 LT4 Engines Kick off NEW Corvette Art Print Series
The Corvette legend has many aspects.Most obvious is the car’s outstanding good looks. Generally it is good to look at the various styles of Corvettes from the perspective of their day – what did regular cars of the day look like. Only then is it obvious how far advanced Corvette styling has always been.
You can order your print today from our safe and secure Amazon store, HERE.
Equally important within the Corvette mystique is what’s under the hood. Many Corvette engines have become automotive heroes and legends. I am launching a new Corvette art prints series called, “Corvette Engine Blueprint Series.”Continue reading “
The Grand Debut of NEW Corvette Engine Blueprint Series” →
Dateline: 1.7.17 –3D Printing Makes Working LS3 Corvette Model Engine
Most of us are at least lightly familiar with 3D Printing. It’s an amazing leap that has its roots in ink jet printing. Back in 1990 I bought the first HP ink jet printer as an alternative to a cheap $150 dot matrix or an expensive $2,500 laser printer. The HP Ink-Jet Printer cost me $950 and was promoted as a “deal.” But we never dreamed that the basic mechanics of the back-and-forth spraying of ink would one day lead to the spraying of a sub-strait material to build 3D “things”! Here’s the video…
All of the parts of this kinetically functioning LS3 model engine were 3D printed and the parts all go together just like the real thing. Continue reading “
Stunning 3D Printed LS3 Corvette Model Engine – Video” →
by Patrick Rall as republished from Torque News, Photos Torques News Staff Lingenfelter Stage 2 Safely Adds 100hp, 100tq to the Corvette Z06
Dateline February 2, 2016:The folks at Lingenfelter have just announced their Stage 2 package for the C7 Corvette Z06, which lifts the output by 100 horsepower and 100lb-ft of torque in a very reliable way – adding improved internal engine components rather than just jamming in a bunch more boost. Continue reading “
650-HP Not Enough for Your Z06? Lingenfelter Safely Adds 100-HP to the LT4″ →
by Scott Teeters as written for Vette Views January 4, 1963 – GM President and Chief Operating Officer, Jack Gordon gives Chevrolet General Manager, Bunkie Knudsen approval to proceed with an all-new big-block engine to replace the W-Series 409/427 engine
Dateline January 2016:When you think of “big-block” Chevy engines, the Mark IV, aka “Porcupine,” Rat Motor” usually first comes to mind.But the first Chevrolet “big-block” was the W-Series engine that was in production from 1958 to 1965 – only eight model years! Continue reading “
1963: Corvette’s Bunkie Knudsen Produces All New Mark IV Big Block Design” →
by Patrick Rall as republished from Torque News New LT4 crate motor package injects C7 Corvette Z06 power
Dateline 12.9.15:If you are shopping for a very special person in your life who is rebuilding a classic Chevrolet Camaro, Corvette, Chevelle or El Camino and you want the most bang for your buck, the new LT4 crate motor package injects C7 Corvette Z06 power into any old school GM muscle car. Continue reading “
Get Your Favorite Chevy Fan a Corvette LT4 Engine as a Terrific Gift!!” →
Words and Art by K. Scott Teeters as written for Vette Magazine and republished from SuperChevy.com
Illustrated Designer Series No. 221: The First LS-Series Muscle Motor
There are many factors that go into the halo of a Corvette. Most obvious, of course, is the car’s extraordinary good looks. Regardless of the generation, compared to its peers of the day, there was nothing else on the road like a Corvette. A “Vette” has always stood out. “Performance” comes next. Continue reading “
