Legendary drag racing engine builder Sonny Leonard, whose name is virtually synonymous with big-inch mountain motor Pro Stock and Pro Modified racing, has passed away.

After building engines as a hobby, Leonard opened a two-bay shop known as Sonny’s Garage in 1968 in Madison Heights, Virginia. The business flourished and in 1977, he moved to a 5,000 square-foot facility. Leonard campaigned a number of racecars under the “Southern Rat” name through the late 1970s and 1980s, through which his on-track testing led to a number of performance developments. In 1987, Leonard made history with customer Bill Kuhlmann, who pushed his brand-new 615 cubic-inch Sonny’s engine to the first 200 mph speed in history by a bull-bodied car.

Leonard’s accolades as an engine builder stretches for miles: 13 IHRA Pro Stock world championships and countless world records, event victories, and championships in drag racing and truck pulling spanning half a century. Leonard also built the first 800-plus cubic-inch engine and the first 500 cubic-inch small-block Chevrolet, developed the GM hemispherical cylinder head, and the 5.3-inch bore space wedge cylinder head. In recent years, his team built a massive 1,005 cubic-inch mill, the largest such engine to be built for drag racing.

Leonard last updated his social media on December 28, noting that he was in the hospital suffering from pneumonia but was showing considerable sign of improvement.

“Sad day for the racing family,” stated Radial versus The World and Pro 275 racer Mark Woodruff, a longtime customer of Leonard’s. “I was lucky enough to call Sonny Leonard a friend. I will sure miss his phone calls asking how I was doing. He was always super excited for our racing updates. He will surely be missed. RIP my friend.”

Radial-tire racer Jim Howe, Jr. echoed the sentiment, adding “Another legend gone. Sonny helped me out a lot in the early 90s in my IHRA days. He knew I didn’t have the budget to buy his motors and took the time to help dad and I with cylinder head and camshaft and nitrous stuff. RIP to a legend. Fly high my friend.”

The staff at Sonny’s Racing Engines, in a prepared statement said: “As most of you have heard , unfortunately Sonny passed away this morning. He will will be deeply missed beyond what words can describe, but we want to reassure our customers that Sonny’s Racing Engines will continue to thrive and remain open for business.”