And that raises the question of, what's wrong with just cutting a V-8 in half? That's been done before successfully, right? Dennis Weglarz, manager, GM Racing Powertrain answers with, "Creating an overhead-valve Midget engine by cutting off one cylinder bank of a V-8 engine positions the camshaft on the intake side of the engine. Our key design decision was to relocate the cam and pushrods to the exhaust side of the cylinder case. This opened up the intake side of the cylinder head and allowed our engineers to optimize airflow without compromising the intake ports to accommodate the pushrods. Relocating the camshaft to the exhaust side also opened up new options in positioning the spark plugs and fuel injector nozzles. It also locates the camshaft lower in the chassis and offsets its weight to the left side of the car, which can be advantageous to handling. The exhaust-side camshaft is really the cornerstone of the Chevy Midget engine's design concept."

Speaking of weight, Chevy is being cagey about what the new motor actually weighs. When pushed for an answer, they say only it is within current, competitive engine weights. That would put it less than 250 pounds But with the new manufacturing design of the block and heads, it's easy to see there is no wasted metal. Traditionally, when factories give out stats such as weights and actual horsepower numbers, they are usually conservative at best. Still, the idea of over 350 hp in less than 250 pounds of four cylinders makes for a healthy motor.

GM also kept one eye on the type of racing where this engine would see duty. "Another key decision that enabled the innovative repackaging of the valvetrain was to invest in an all-new block and a cylinder head that wasn't constrained by the limitations of being usable in other forms of racing," says Pat Suhy, GM Racing group manager, Oval Track. "Our goal was to produce an engine with power that's equivalent to the most powerful engines currently competing in the USAC Midget series while maintaining a wide power band. Midget racecars run without transmissions, and they race on tracks that range from 0.1-mile arenas to the one-mile Phoenix oval. The engine's operating rpm range extends from 4,000 to 9,000 rpm, and throttle response is critical, especially on dirt tracks where the driver uses the throttle to help turn the racecar."

And then there are the costs involved. "Another important consideration for a grassroots racing series is cost," Suhy notes. "Our objective was to produce an engine that delivers great performance for the money. The Chevrolet brand has always stood for value, and the Chevy Midget racing engine will continue this tradition."

Initial track tests by Tony Stewart Racing have confirmed that GM Racing hit the mark with the new Chevy Midget racing engine. "So far in testing, we've learned that the Chevy engines don't ever seem to run out of power," says Tracy Hines, driver of the No. 21 TSR/Chevy/Spike USAC National Midget. "From the instant you get on the gas, the engine never quits pulling. They're strong on both the bottom and top ends of the power band, and it feels as though the engine has power in reserve. Chevy has built a great piece and I'm really looking forward to competing with these engines."

TSR plans to complete its transition to Chevrolet power as soon as possible. "The opportunity to be a part of the development and debut of the new Chevy Midget engine is something that I'm really proud to be involved with as a driver," says Levi Jones, driver of Stewart's No. 20 Midget. "Looking back at the history of open-wheel racing, there have been several influential engine programs that have left their mark on the sport. To be one of the drivers to compete with the first-ever Chevy branded USAC engines will definitely always be one of my career highlights."

Midget racing has had a long and storied career of ups and downs in popularity. As it seems to be surging once again, this new piece can help draw even more attention. We're watching to see if it attracts some of the other Detroit biggies to get involved.

SOURCE
Chevrolet Tony Stewart Racing