The History of the General Motors Small Block
At the start of the new year, Chevrolet will unveil the latest version of the Corvette, and it will likely be nothing short of amazing. At the heart of that is the latest version of the General Motors small block V8. It is called the LT-1 (above) and will be the most powerful V8 engine from GM to date. It is sophisticated, fuel efficient, yet potent. and will be propelling one of the most lauded sportscars on the planet, the Chevrolet Corvette. But all the while, under the hood, was one an engine of humble beginnings that was so well engineered that it was able to be modified through the generations, so that even under today's Corvette, the same basic layout is there. We're going to delve a bit into what makes the GM small block so great. Why does it matter to you? Well from Camaro to Silverado and Savanah to Express, and Impala police car, the GM small block has always been there. To get a better understanding of just how important the GM small block is to the American automotive sector, we spoke with a man who just might know a little bit about the V8: GM Technology Communications and powertrain rep Tom Read. Tom was able to give us some serious perspective on the small block: GK: What made the design of the small block so revolutionary at the time? TR: There are a number of design features that made the small block revolutionary. More than anything it is probably best known for its compact size and light weight. Its original length was only about 22 inches long and it weighed less than the inline 6 it replaced while being more powerful at 195 horsepower. Stamped steel rocker arms contributed to higher engine speed capability and a strong lubrication system contributed to long life and great durability.
GK: How did its debut in the automotive world affect not only GM performance, but the whole of the performance car world?
TR: Chevy fans the world over might have better answers to this question better than I. In my estimation there isn’t a single correct answer however the engine developed a following for a few simple core reasons including an elegant design that’s conducive to power development, great power to weight, durability and interchangeability of parts. As the Small Block improved, the improved parts, especially cylinder heads, could be added on to older Small Blocks. This wasn’t always the case with competitive engines.Did I mention great power development?
GK: What has been the secret to the staying power of the small block?
TR: We would like to think that there is single answer to that question but we haven’t found it. We produced our 100 millionth small block late last year and if you think about it there are probably dozens of reasons embodied with those millions of customers as to why the Small Block is so loved. There is a kind of mystique behind the staying power but there is a core design formula key to its success: Design an engine to exceed customer expectations in terms of power, durability and reliability. I think the Small Block hit, and continues to hit, that mark.
GK: Talk about some of the biggest advancements in the small block through the decades.
TR: Advancements and adaptability are a hallmark of Small Block. Technology integration over the years are too numerous to list. Highlights arriving in the first generation included using fewer casting cores for manufacturing simplicity and light weight and fuel injection. The second generation included electronic fuel injection, roller lifters and rocker arms. The third generation saw a deep skirt block, six bolt mains, composite intake and electronic throttle control. The fourth gen was introduced with active fuel management, variable valve timing and transverse drive configurations. Stay tuned for more advancements in Gen 5 including a direct injection fuel system.
GK: Talk about the small block today. What technology allows it to compete with larger vehicles in fuel economy?
TR: The modern small block is one of the most efficient engines in the industry. Truck versions take advantage of cylinder deactivation which is also known as Active Fuel Management. This technology seamlessly deactivates four of the eight cylinders when they’re not needed to save fuel. When power is needed the cylinders are reactivated for power on demand. This all happens in the blink of an eye and gives the Chevy or GMC truck owner superior capability with excellent efficiency.
GK: Future for the small block with ever-stringent fuel economy. At some point will it be too difficult to get that fuel economy out of a V8?
TR: The future isn’t without challenges but the adaptation of the Small Block to fuel saving technology isn’t over. GM has some of the best resources in the world for engine and fuel-saving technology development. Stay tuned, our next generation small block will have a direct injection fuel system which provides improved power and efficiency which is something everyone can live with.