You might know Sonny Leonard from his line of 1,000-cubic-inch V-8s or his pioneering work with Pontiac heads and Pro Mod racing. Automotive journalist Rod Short spoke with Sonny before he died to share the history of this legendary engine builder. -HOTROD Humble Beginnings After 50-plus years of developing engine combinations ranging from 400 to 1,000 cubic inches, many people are surprised to learn where Sonny Leonard came from. Following his time in the U.S. Army, Leonard was employed as a tech at a Chevrolet dealership where he put in extra time on nights and weekends to make a few bucks so he could drag race. After selling his car and borrowing $300 from the bank to start his business, Leonard and his wife Frances set out on their own to open a shop in a 300-square-foot building that could barely fit two cars. He worked on anything that had wheels, anything that would pay the bills to keep his business going. That ranged from fleet truck maintenance to farm equipment to other racers cars. Leonard would do the hardest jobs, the ones that involved internal engine work the big retail names didnt have the expertise to do. High-performance street and strip engines had to have closer machine tolerances on components. That meant sometimes taking a two-hour round trip to the nearest performance machine shop to get work done that Leonard didnt have the equipment for. Making that trip cost extra time and money that couldnt always be charged back to a customer, so he took it upon himself to learn some new skills so he could bring that work in-house. Leonard recalled, I thought maybe Ill buy some equipment of my own, but I didnt have any experience in machine shops, so I went to night school. Leonard borrowed money for machine shop equipment so he could apply what hed learned and then relocated his expanding business to make room for everything. He used that to build some engines for his drag-racing hobby and soon developed a local following that had seen how well his car ran at the track. Making a Name In the early 1980s, Leonard put together a 540-inch engine combination for a young Ohio bracket racer named Chuck Sneed who wanted to try his hand in IHRA and AHRA Pro Stock. Sneed surprised people with his performance, becoming a member of the Holley 7-second club. The run whatcha brung style of Southern drag racing meant getting more power by whatever means was necessary, so Leonards recipe for big-cubic-inch engines was in demand. Business continued to grow, forcing him to relocate his shop again to get more space. In 1987, a little-known Midwestern racer named Bill Kuhlmann bought a 615-cubic-inch engine kit from Sonnys, added some nitrous, and ran it at Darlington in Top Sportsman. He came home from that event with national recognition of being the first driver in a doorslammer to ever break 200 miles per hour. I really didnt think that it was so important to his racing to be the first full-bodied car to run 200 miles an hour, Leonard said at the time. You could run 199 all day, and it aint no big deal, but you run 200? I didnt realize how important that was. I just didnt think much about it. But when he did it, that was something. Ted Jones, who was the IHRA president then, decided to create a heads-up class to accommodate these powerful, crowd-pleasing cars that we know as Pro Modifieds today. From Mountain Motor to Monster Engines The popularity of Kuhlmanns performance had a huge impact on racing as a whole as big mountain motors became all the rage. The demand for bigger and better race engines had maxed out the limits in cubic inches of what a stock block could accommodate. Many thought that engine development had hit a wall. I believed back in those days that engines could only get about 540 or 550, tops, Leonard admitted. Those were mountains back then, but in todays world, they are effectively molehills now. Leonard met that challenge by abandoning the use of factory production car and truck engines in favor of aftermarket blocks with larger dimensions. Raised cam locations, spread oil pan rails, and larger-bore centers provided room for larger and larger displacements. He helped design the features of an aluminum block with Donovan Engineering. That, in turn, necessitated the need for better internal engine components that could safely handle the greater stresses of racing. Larger-diameters pushrods and camshafts were developed to minimize flex, while connecting rods and rod bolts began to use space-age technology for superior strength. Castings for cylinder heads, for instance, were greatly improved by hot isostatic Pressure technology, which helped eliminate porosity issues while providing stronger, lightweight blocks. The culmination, at least for now, was the groundbreaking 1,005-cubic-inch engine that was later developed and built for an overseas customer. New Directions Sonnys Garage, as the business was first known, grew into Sonnys Racing and narrowed its focus to just competition engines. As international business grew, the name evolved into Sonnys World Class Racing. Recognized for its forward-thinking and product quality, inquiries from the truck-pulling and high-performance marine communities began to ask for Sonnys expert services. Though not publicized, the business had a hand in NASCAR and motorcycle racing, as well. It all came from the recognition and praise that Sonny Leonard had earned from his longtime customers. New Yorker John Montecalvo, who won Pro Stock association championships in three different series with Sonnys power under the hood, was an example. He has always been progressive and on the leading edge of technology. If there is a way to make more horsepower, Leonard and his phenomenal employees would find it, he said. The Legend Continues Well into his seventies, Sonny Leonard was a regular presence at his business, along with his wife Frances and daughter Kelly. A wide array of customers from every corner of racing across the globe continues to seek parts, engines, and knowledge from Sonnys World Class Racing. You had to have the drive, Sonny said about the secret of his success. You want to do it, you want to be better, and you want to do better than the guy in the next town, so you worked a little harder and a little harder. You gotta like what you do if youre gonna do really good at it. From those humble beginnings in December of 1968, Sonnys World Class Racing rose in prominence with innovative engine designs and uncompromising performance. Thats resulted in well over 100 national and world records on land and sea. In mountain motor Pro Stock alone, Sonnys engines have amassed 17 championships within the PDRA, IHRA, and ADRL. Thinking back on the past half-century, Sonny still cant believe how far the business has come. When I think back to my time at that little 300-square-foot building where I started, we didnt even know if wed make it or not, he said. When its all said and done, his was a lifetime of determination, hard work, and the success that came with it. It was the fulfillment of the American dream. --> The post Sonny Leonard, Engine Builder, Dies at 77 appeared first on Hot Rod Network .