It’s been a couple of years since Virginia-based engine builder Sonny Leonard announced plans to offer the industry’s first 1,000-cubic-inch V8 for the auto racing and enthusiast market. His first bullet (shown above) displaced 1,005ci and pulled 2,118 horsepower at 7,700 rpm on the dyno. It was featured extensively in the media and is now racing in Australia.
But what has happened since with the 1,000ci program?
“There aren’t a lot of racing classes for engines with a 5.4-inch bore spacing,” Leonard tells EngineLabs. “Most of the rules say 5.3-inch.”
“It starts, idles and behaves like your new grocery car,” reports Thau, “but sounds like thunder!”
Thau says early dyno tests are showing over 1,360 horsepower and 1,314 lb-ft of torque, but he’s running out fuel at 5,500 rpm.
“I’m working on bigger injectors,” he adds.
The street engine runs a 12.5:1 compression ratio while the race engine was built at 17:1. Other differences include a milder cam, and the billet 12.225-inch deck height block is machined with exterior scalloping to accommodate water jackets. Otherwise, short-block similarities include Bryant 5.875-inch-stroke crankshaft, GRP rods, SAR pistons (5.220-inch bore), ATI balancer, Jesel belt drive and Dailey dry-sump oiling.
The tall deck and wider bore spacing require a custom sheet-metal intake manifold, topped with four Accufab throttle bodies. The injectors are controlled with a BigStuff3 ECU while the spark is timed by MSD.
“But if anyone ever wants to go over a 1,000 cubic inches,” says Leonard, “we can do it!”
Meanwhile, EngineLabs will keep monitoring Thau’s progress as he finalizes the tune on his 1,000ci street engine. Be sure to check out the video above to hear the thunder.

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