SCIENCE & ENGINEERING NEWS
Welcome, N.C. — Anna Turnage reports that every NASCAR racing team lives to win. But as the operations staff at Richard Childress Racing (RCR) will tell you, the race begins long before the weekend event.
From the time the checkered flag is waved until the next race, RCR engineers and researchers are not only racing against time, they’re competing to find the best technologies that will gain their four drivers including seven-time NASCAR Winston Cup champion Dale Earnhardt the next win.
“What we do Monday through Friday really determines what happens over the weekend on the track,” says Lenny Batycki, vice president of operations at RCR. “We have to know far ahead how our engines are going to perform.”
Performance is the RCR Research and Design Lab’s business. A wonderland of technology, the shop is where some of the best-kept secrets in racing reside. State-of-the-art CAD/CAM software, giant CNC and CMM machines, and Raindrop Geomagic digital duplication software are among the many weapons the staff uses to gain that extra thrust of horsepower for the next race.
Inside the squeaky-clean lab, the Chevrolet Monte Carlo race car engines are built from the ground up. After each race, they must be taken apart, inspected and rebuilt again. Many of the parts come from Chevrolet. Others are built in the lab. All are retooled to give the cars maximum performance within the confines of NASCAR regulations. Engines are tested with dynamometers that run an engine full throttle to ensure that it will withstand a five-hour, pedal-to-the-metal race.
“The skills we have in this shop have an awful lot to do with what the outcome will be,” Batycki says.
RCR engineers are intensely trained to deal with some of the most powerful engines in the automotive industry. The V-8 Winston Cup engine runs at about 750 horsepower, with speeds as high as 200 mph. It has a 12.5:1 compression ratio with a maximum 358 cubic inches. A Busch series engine runs at about 500 horsepower with a 9.5:1 compression ratio and a maximum of 358 cubic inches. But it’s what goes on inside the lab that makes each race car engine unique.
There are many tricks of the trade that will make a race car engine gain more horsepower. But perhaps one of the most difficult, and most secretive, is cylinder head porting.
“The cylinder head port is the heartbeat of the engine,” says Greg Jones, design engineer at RCR. “It is pivotal to the success of the car. Except for the cam shaft, cylinder head porting is the most guarded secret in an engine department.”
Cylinder head ports allow air and fuel to travel through the cylinders. The more cylinders there are in a car, the more power it has. Cylinder head porting is when engineers reshape the ports to improve efficiency by removing flaws that come from the factory. It also reduces restrictions in the engine’s intake and exhaust tracts, allowing more air and fuel into the cylinders, thus increasing horsepower.
The cylinder head porting process is so intricate and complex that it takes a true craftsman with a lot of patience to get it right. In NASCAR, teams use different cylinder heads for different racetracks. Some tracks are faster than others, some are longer. Some tracks fall under NASCAR’s restrictor plate rule, which makes the cylinder head ports even more important for increased horsepower.
“We’ve gone through six cylinder head designs in six months,” Jones says. “We are constantly searching for better performance.”
For years, all of the cylinder head porting at RCR was done through a long, labor-intensive hand-grinding process. It took 40 hours to complete one cylinder head. “It would take a total of two weeks to complete a pair of heads,” Jones says. “This is not acceptable with the current racing schedule, not to mention any small bit of human error from port to port could decrease horsepower.”
Raindrop Geomagic Studio digital duplication software, working in conjunction with other technologies, has helped create a process that delivers a perfect cylinder head much quicker than ever before. Geomagic Studio makes it possible for RCR engineers to take output from 3D data, capture the texture and shape of the cylinder heads, and transform this information into models that can be used over and over again, saving days in production time.
“Geomagic allows us to take the model from its digitized state and surface it,” says Jones. “We can visualize it a lot quicker and it allows us to make alterations right there on the screen. Visualization is important because we can determine if there are any glitches in our data that will be machined in the CAM package.”
The cylinder heads are first digitized with a CMM machine. The digitized data is then pulled into Geomagic Studio, converted to a polygonal model, then to a NURBS model, and exported into a watertight surface that can be manufactured within .0001-inch of the original model.
“In this business, you have to be very accurate with your surface,” says Jones. “Any fraction off can mean the difference between winning and losing a race. Geomagic Studio is as accurate as I’ve ever seen.”
RCR engineers use Parametric Technology Corp.’s Pro-NC software to complete the design process. The digital design model is then sent to the RCR manufacturing division, where an Okuma CNC machine produces the finished product. The entire process of porting two cylinder heads, which used to take 80 hours, now takes just 12.
“Everything is based on performance in this industry,” Jones says. “Geomagic helps make optimum performance possible. The beauty of it is that we only have to make one model, then we can copy it. This saves us a tremendous amount of time in production.”
At RCR, the quest for the checkered flag goes beyond the four drivers: No. 3 Dale Earnhardt and No. 31 Mike Skinner in the Winston Cup Series, No. 2 Kevin Harvick and No. 21 Mike Dillon in the Busch Series. The race starts on Monday, when the engines are back at the shop, ready to be pushed for more power.
“We have four drivers here, but we have 180 racers,” Batycki says, referring to the entire RCR team. “Everybody who works here has that much passion for racing. And they all push to the limit to get us where we want to be on race day.”