There is no denying that crate engines have changed the racing landscape-possibly forever. Maybe it was just the tip of the economic iceberg, but we've noticed tracks and engine builders offering more options than ever before for racers looking to pinch every last penny.
Take, for example, the recent development of spec racing engines. Spec motors that require a certain combination of parts have been around for decades, but until recently most were usually limited to a specific cylinder head or intake mandated by the track promoter. But now we're seeing engine builders putting together some pretty ingenious engine packages in order to stay competitive with the crate onslaught.
This newest generation of spec motors are capable of providing big horsepower on a budget. And unlike most crates that are built from mainly stock OEM components and must be treated with kid gloves, these specs are built from the ground up with racing in mind. They may cost more up front than a crate motor, but the idea is that they should be able to provide good, raceable power and do it for a season or more without needing a rebuild. It's just one way to help save the racer money in the long term to help keep the sport healthy.
"I've been on both sides of this deal," says Comp Cams' Scooter Brothers, who has consulted on several different new spec motor projects and understands the difficulty of helping racers save some money in an environment where-let's face it-money can often buy speed. "I've been a racer, a promoter, an engine builder, and now I'm a parts supplier. One thing I've learned is that a racer will compete at 100 percent of his ability and spend about 110 percent of what he can afford to spend.
Dorton says that he chose...
Dorton says that he chose his components very carefully for his 387ci small-block. The Dart SHP block is incredibly strong and durable yet still cheaper than a Chevy Bow Tie block. Notice the expanded water jackets around the cylinder bores for exceptionally consistent cooling. The crank is a tough Callies forged unit with 3.625 inches of stroke.
"I'm not sure we can ever change that or make racers believe they can perform better when spending less. However, if they can be shown how to spend the right amount in the right places, it might free them up to last longer, race more, or win more, and be more successful. As long as they can feel competitive and feel that there is a way to exploit some tiny loophole to make themselves better than the next guy they will find a reason to compete and be happy. It makes very little difference how fast they go or how much power they make as long as they are competitive."
But what is also interesting is that a few forward-thinking engine builders have taken the reins from the promoters and instead of simply building to a rulebook have produced their own spec engine designs and made them available for any track promoter or series that would like to give them a shot.
A hydraulic roller cam is...
A hydraulic roller cam is a consistent feature with almost all the new spec motors we are seeing. Rollers eliminate the need to the special lubricants that flat tappet cams require and make easy power. Hydraulic lifters help absorb some of the shock that can damage valvetrain components and, in addition to being nearly maintenance free, help the entire valvetrain run smoother longer.
To give you a better idea of just what's available out there, we've taken three very different examples from three different engine builders. Keith Dorton of Automotive Specialists is a longtime stock car racer who can trace his roots all the way back to Holman and Moody and has built winning race engines for the late, great Dale Earnhardt. His spec engine design most closely resembles the classic stock car formula with a few key differences that make it quite interesting. Meanwhile, Mast Motorsports has a more road-oriented heritage and has developed a range of spec motors utilizing tuned port fuel injection. And finally, Sprint Car racing icon Ron Shaver has developed a spec motor for the Sprint guys that keeps the traditional elements that makes the engines so unique while mixing in some key low-cost components. Shaver has also taken a unique step when it comes to dealing with the age-old issue of cheating.
There's something here for just about everyone, and this is certainly only the first wave of the new generation of spec racing engines. It's going to be exciting to watch how this all will develop.
Traditional but with a Twist "I've been pretty up front all along that I don't think crate engines are a good idea for racing long-term," Dorton says of developing a spec motor that's an alternative to crates. "But it's obvious that you had to either get on board in some manner or get left behind-and I had no doubt that we could do something better than what's out there."
Dorton's answer is a spec motor that remains easily recognizable as a small-block stock car racing engine. But because he's not restrained by the typical rulebook, he can make some changes that improves durability while keeping costs down.
"The problem is we had painted ourselves into a bit of a box," he explains. "Even though everyone's rulebook is a little bit different, they all follow the same principles. And the only way to continue making more power is to increase the rpm. But anytime you push the rpm levels, your expenses go up and rebuild intervals go down. So with the new spec motor instead of chasing rpm we simply added displacement."
Instead of the usual 358 cubic inches, Dorton chose a Dart SHP Chevrolet-style block than is lightweight, relatively inexpensive compared to a Bow Tie block and can easily handle a 4.125-inch bore with 3.625 inches of stroke for 387 total cubic inches. Dorton also outfitted the drivetrain with a hydraulic roller cam and lifters. The hydraulic system combined with a cam lobe designed to make a broad torque curve while being gentle on the valves, puts the redline at a respectable 7,800 rpm. Dorton says that while he wouldn't recommend it for extended periods, one of the test engines has been run as high as 8,200 rpm safely.
Dorton points out that a lot of work went into the valvetrain to produce good power at just the right rpm levels. "A motor with lots of consistent torque is not only easier to drive, but they also produce better racing. Plus, these motors produce enough rpm that they really sound like a race motor should," he adds.
A look at the rod and piston...
A look at the rod and piston combination reveals another clue to just how much thought Dorton put into his engine package. A 6-inch rod helps maintain a good rod/stroke ratio with a 3.625-inch stroke crank. The Mahle pistons are custom forgings with coatings throughout for good durability and use a 1.5 mm, 2 mm, 3 mm ring package. But notice the symmetrical valve pockets. Dorton says having the pistons made this way allows him to cut down on cost by reducing the piston inventory needed.
Horsepower can be adjusted between 600 to 650, to suit the needs of the cars and the desires of the series director, with just a carb change. Currently, Dorton expects this package to sell for approximately $26,000, which includes everything from the ignition and wiring harness, to the carburetor, and even the power steering pump. "The crate motors are typically only a long-block," he says, "so when you add in all that's required to get one running, the costs get a lot closer than you might think. Plus, you still don't get anywhere near the horsepower that this spec motor is capable of. Here, we're talking the equivalent horsepower of a NASCAR Nationwide engine at 1/3 the price. And our test motors have shown that we can race these between four and five thousand laps between rebuilds, which should get most racers through an entire season no problem."
Join the LS Revolution It has been quite a few years since a first generation small-block that is the staple of stock car racing has appeared in any new GM vehicle, but that doesn't mean that the cam-in-block small-block is dead. It's just grown up a bit.
The GM LS series of engines is carrying on the pushrod engine tradition and has been around long enough that some of the exotic feel of the motor has worn off. In fact, many feel that time has come to see the LS engine widely accepted in stock car racing.