The original 265 cid Chevrolet...
The original 265 cid Chevrolet small-block engine has been the basis for American motorsports for the past 40 years.
Ed Cole is regarded as the...
Ed Cole is regarded as the father of the Chevy small-block.
Herb Fishel is Chevrolets...
Herb Fishel is Chevrolets global chief of racing today, but he started out as an engineer at the short-lived SEDCO facility in Atlanta.
Vince Piggins ran Chevrolets...
Vince Piggins ran Chevrolets racing operations when the Automobile Manufacturers Association shut down factory support of racing.
Wes Yocum was just starting...
Wes Yocum was just starting out at Chevrolet when the small-block came into being, and helped the original team during its creation.
Zora Arkus Duntov was a big...
Zora Arkus Duntov was a big player in the development of the small-block as a racing engine and the preferred powerplant of his beloved Corvette.
The Chevrolet SB2 engine,...
The Chevrolet SB2 engine, which competes in NASCAR Winston Cup and Busch Series, is a direct descendant of the original small-block engine. GM engineer Ron Sperry says todays engine will comfortably fit in a 1955 Chevrolet passenger car.
If you stop and think about it, one engine has made motorsports in the United States for nearly 50 years. The Offy was a great engine, as was the four-cam Ford. Who can forget the mighty Mopar hemis? But the one constant through all the heydays of the engines listed above has been the Chevrolet small-block.
In 1955, Ed Cole and a group of engineers got together and brought about the foundation of modern-day auto racing at a variety of levels with the development of the original small-block Chevy. Today, it is the basis for nearly all Late Model, DIRT Modified and Sprint Car engines in competition.
Chevrolet produced its first V-8 engine in 1917, a 288-cid, 55hp model called the Series D. The engine had overhead valves and cross-flow heads, but it was a little pricey for the day. Just 2,817 examples of the engine were produced before Chevrolet called it off.
The next V-8 engine offered by the company was in 1955-model cars, and it was made available to the public on Oct. 28, 1954. As of its 40th anniversary in 1995, more than 63 million small-block Chevrolets had been produced. Untold millions of them are still on the road.
The Chevy small-block engine has been produced in 10 different displacements ranging from 262 to 400 cid. The production engine topped out at an amazing 375 hp, but race tuners have wrung upwards of 900 hp out of the package in its time.
Ahead Of Its Time
You have to understand just how far ahead of its time this engine was when it was introduced. Thin-wall castings, stamped-steel rocker arms on spherical pivots, hydraulic lifters that metered oil to the cylinder heads by way of hollow pushrods, slipper skirt aluminum pistons, interchangeable cylinder heads with wedge-type chambers and an intake that sealed the lifter valley. Coles sales pitch to the Chevrolet hierarchy went along the lines of, high-performance doesnt have to mean high price. To this day, all small-block Chevy V-8 engines share their basic geometry with the original 265-cid engine produced in 1955.
Until the development of the LT1 engine in the 1990s, the small-block adapted to whatever it needed to be. In the 60s, when performance was king, it grew from its 265-cid original size to a whopping 350 cid. In the early 70s, it went to 400 cid, the largest small-block ever produced. When the energy crunch hit, the small-block was winnowed back to 262 cid. In the years since, it has standardized at 305 and 350 cid.
What does this have to do with motorsports? The development of the Chevy small-block allowed racers from several generations to compete using basically the same engine, and it allowed the tricks of the trade in engine tuning to be passed on via a somewhat level playing field. Consider sports-car racing, for instance. Every year, it seems, there are new engines coming out in different configurations. There are V-8s, V-10s and V-12s, with pneumatic valves and other high-tech applications that make the technology curve that much steeper for both mechanics and drivers, let alone the average racer who wants to work on his engine himself.
Still The One
The Chevrolet small-block has been the basis for American motorsports since 1955, much as the Offenhauser was in Indy car racing from the days of the Millers and Meyer-Drakes. The difference is, according to GM Racings Ron Sperry, you can take a modern-day SB2 engine out of a Winston Cup car and drop it directly into a 1955 Chevy without any additional drilling to get it to fit. Sperry worked with the small-block in the 60s at Chevys Product Performance shop and was a key member of the design team on the SB2.
Fundamental likenesses between the original small-block and the SB2 are its the same bearing size, same bore spacing, the casting configuration ... you could virtually take todays SB2 engine and drop it in a 1955 Chevy and it has the same attachment holes drilled in it, Sperry says. There have been some changes to the production engine to make it different, like the oil filter and things like that that have become remote applications. Basically, the block architecture has been duplicated for years as the same thing. Were looking at things to do now to try to make the cam bearings bigger. Even in the LS1 engine, the current production Corvette and truck engine, we moved the cam up so we could get bigger bearings, bigger journals and bigger lobes and things to reduce stresses. But in the race engine, we still use the 1952 design. Theres different oiling and some other features weve added to upgrade the oiling system, but basically its a 50-year-old engine.
While there have been changes, Sperry says the basics remain the same, transcending advances in technology.
Its a matter of comprehending the fact that you had a single 4-bbl engine youre starting off with, Sperry explains. One of the things the original engine did was to take two intake ports and squeeze them between two intake pushrods. It compromised certainly the size of the ports and the horsepower you could develop because you were trying to get two features in a window that all the competitors had. Ford had an intake and then an exhaust with an intake pushrod on either side of that. Instead of two intakes going through two pushrods, it had one port going through two pushrods. So we sort of adopted that kind of design thinking, and we have other engines that we do that with like the LS1. We mirror-imaged the intake ports so they all went back toward the carburetor, and we moved the features around, but it all bolts onto the same block.
That sort of flexibility is why the small-block Chevy has been the engine of record, so to speak, in American Motorsports for five decades. Really, the mainstay engine in circle track racing today is still the 18-degree small-block, which is a subtle variation of the original 23-degree engine, Sperry explains. Its a roll of the casting to stand the valves up and get the ports up in the air a little higher. The SB2 is a bigger departure from that, it does have some compound valve angles in it on the intake side and it does have a little more reach as far as rocker-arm geometry, but it is still fundamentally a small-block Chevy. Maybe youre taking some of the big-block thinking and marrying it into the small-block design, but its still the same engine.
Since the small-block has had such a long life, it has enabled the knowledge to flow freely from one generation of racer to the next, which has been huge for the racing industry. Its also been pretty good for Chevy, as emphasized in the number of racer-oriented changes over the years.
Think about the number of dynos spinning small-block Chevy engines, Sperry says. Many people called us back and told us, If you just changed this, we could go farther. That was a lot of our input to what we did to the racing cylinder heads, from the Turbo heads in the early 70s, to the Bow Tie heads in the late 70s and early 80s to the aluminum stuff today, all those were basically racer-driven changes. With CNC porting, we now actually make the engine as a part to be machined. Our challenge is to make the outside of the thing OK and move the water around so they (engine builders) can get whatever shapes they want into the piece. Were just making an envelope for them to carve their signature pieces into.
The Fathers Of The Small-Block
Lets take a look at the father of the small-block Chevy, Ed Cole. Cole was Chevys chief engineer when the small-block was born. After supervising the development of the Cadillac overhead-valve V-8, Cole arrived at Chevrolet in 1952. When he got to Chevrolet, he found a 231-cid V-8 engine being developed to mirror the Caddy powerplant, and he immediately scrapped that plan in favor of a lightweight, compact and powerful engine that became the small-block V-8. A brilliant engineer in his own right, Cole ramrodded a team that worked six days a week, 10 hours a day to complete the design. Along the way, several breakthroughs were made to form a confluence of events that changed the shape of engine technology for the next 50 years.
A casting technique, called green sand, allowed the V-8 block to be cast upside down and significantly cut the number of cores required. A wafer to meter oil from the valve lifters to the hollow pushrods was designed by Loren Papenguth, and Clayton Leach developed the stamped steel rockers that increased the rev limit of the new engine.
The cylinder head design came about through the efforts of Don MacPherson. I sketched until I came up with the head configuration, MacPherson said on the occasion of the engines 40th anniversary. Upon seeing the sketches, Ed Cole said, Thats it! I was not at all convinced that those sketches would make a workable cylinder head, but fortunately they did. The heads featured cross-flow ports and five head bolts around each cylinder.
Zora Arkus-Duntov, a Russian émigré born in Belgium, became the father of the Corvette and participated heavily in the development of the small-block as a racing engine. Another who helped push the small-block to its heights of racing glory was Vince Piggins, who kept the racing spirit alive at Chevrolet after the Automobile Manufacturers Association, instituted a self-imposed ban on motorsports activities in 1957.
Piggins, who was fresh off domination of NASCARs early years at Hudson, formed the Southern Engineering Development Company (SEDCO) in Atlanta at Chevrolets urging. While it was billed as an engineering development entity, its real business was fielding winning stock car teams in NASCAR. In fact, it acted as Chevrolets factory team in the shadows of the ban. Duntovs beloved Corvettes prepped for Sebring in the remote garages of the SEDCO facility. Piggins is also the man credited with the creation of a classic Chevrolet racing carthe Z28 Camaro. Although Piggins envisioned the Camaro as a perfect foil for Fords Mustang in the SCCA Trans-Am Series, the Camaro was perhaps the most-raced car in America through the 70s and 80s and still enjoys a healthy presence on Americas short tracks. All Piggins had to do to get the Camaro off the ground was convince Chevrolet GM Pete Estes that the Camaro was worth the trouble of building a 302-cid small-block engine to fit the SCCA rules. A single demonstration ride in a handbuilt Camaro was all it took.
After SEDCO was disbanded, Piggins landed in the Chevrolet Product Performance Department, where his primary focus was to conduct economy runs and performance trials. His real responsibility, however, was to make sure the flow of high-performance parts to Chevy teams was kept intact.
Perhaps Piggins most valuable contribution to the small-blocks longevity was the creating of a stealth motorsports department inside the Product Performance (it later was known as Product Promotion) stable. Bill Howell, Paul Prior, John Pierce, Sperry and Wes Yocum were part of the secret engineering team, along with a young engineer from North Carolina named Herb Fishel.
Fishel, who graduated with a degree in engineering from North Carolina State, was a stock-car fan from the word go, and eventually found himself at the epicenter of Chevys racing activities. In 1968, Fisher was the senior engineer on the Z28, L88 and ZL1 engines, and in the early 80s he went to Buick Special Products Engineering. While there, Buick won consecutive NASCAR Winston Cup titles and started its Indy V-6 program that eventually resulted in one- and four-lap qualifying records at the Indianapolis Motor Speedway. The late Scott Brayton still has the turbocharged stock block record at IMS, hitting 233.851 mph over one lap and averaging 233.718 for four.
In 1983, Fishel returned to Chevrolet in the Product Promotion department and was in charge of Chevrolets high-performance racing activities. The company renamed the department the Chevy Raceshop, and Fishel is still the global racing chief for Chevrolet in the Motorsports Technology Group. So there you have it, an abridged history of the racing engine thats outlasted 10 presidents and is still the engine of choice in todays motorsports world. Its Golden Anniversary is just around the corner in 2005, and it will likely still be going strong many years past that.