The New SB2 Engine

GM's introduction of the new SB2 engine, with its intake valve angle at 12 degrees instead of the current 18 degrees, promises better torque performance on the race track but means lots of work ahead for engine builders.

How significant is the SB2's introduction in NASCAR?

"It's probably the biggest design change the Chevrolet V8 has ever seen. Even though it will basically use the same engine block, the configuration of the cylinder head is drastically different from what we have worked with over the past 30 years. The previous engine's 18-degree angle intake valve is drastically different from the SB2's 12-degree angle. The manner in which the ports and the chambers are laid out in the SB2 enhances the combustion process, thereby increasing the ability to produce power."

Differences between current engine and SB2?

"The biggest differences are in the port layout, valve angle and combustion chamber design. The only things that remain the same are the crankshaft, rods, oil pan and water pump. Other than that, everything has to be changed to accommodate the new cylinder head."

What does the SB2 mean for the Gumout team?

"At Bahari' Racing, we are looking at throwing away 25 engines that cost about $35,000 each, and essentially starting over."

How will the SB2 impact performance?

"The SB2 is designed to level the playing field. Our problem hasn't necessarily been the horsepower number differentials. We suffered more in the torque curve down below the peak horsepower number. The difference in the torque in the lower portion of the rpm curve is a big factor in the acceleration of the car. That's where we can really gain the most with the SB2 engine.

"Considering the way these drivers get on the throttle today with the tires and chassis they have, Ford's engine characteristics are so much better at the entry point of the rpm range and the terminating point than the GM's. In short, the GM cars should start getting off the turns better than they are now."

Keys to development?

"What we are concerned about is increasing the torque in the 7,000 to 8,000 rpm range. That's important because at most tracks the engine works in that range most of the time."

Where will fans notice the SB2?

"It's pretty difficult to answer where this engine will be most effective. It will definitely help at places like Atlanta, Charlotte, and Michigan, where we felt the Fords dominated. What matters most on the shorter tracks will be the throttle response. It's a possibility the response on the short tracks will be less than what we have now, but that is something that over time will be addressed and corrected."

Are you concerned about the work that lies ahead?

"It is definitely satisfying when you overcome an obstacle, solve a problem or measure up to a challenge. GM has done a tremendous amount of testing, and I think we will be just as well off as if we stayed with the old engine."

How long will the SB2 used in NASCAR?

"I don't see it around for 30 years or anything like that. I think down the road you might see four-cylinder, dual overhead cam, four-valves-per-cylinder engines. I think that approach may be one way to get us away from the restrictor plate. With today's technology this engine we are using is far behind the times. Hopefully in the near future we can look at things like that."

How will the restrictor plate SB2 compare to the current restrictor plate engine?

"It will generate the same challenges and problems as the old engine. A lot of the things we learned with the old engine can be applied to the new engine."

Will the engine sound or fuel mileage change?

"I don't think you will hear a difference in the sound unless something drastically different in the header arrangement occurs. The sound should be virtually the same. I don't think fuel mileage will be greatly changed either."