Charlotte, N.C. — The general levels of horsepower across the NASCAR Winston Cup makes has increased about 20 horsepower since the early season race at Las Vegas. That 20 horsepower represents a 100 percent increase of the normal annual increases the industry has seen in past years. However, with GM and Dodge believing they are behind the eight ball when it comes to horsepower production from their vintage 1999 and 2000 motor packages (GM and Dodge respectively) recent dyno testing could foreshadow changes.
Teamfordracing.com learned several weeks ago that the numbers gathered from the NASCAR Indianapolis Motor Speedway tests showed that the Robert Yates motor turned the highest horsepower readings on the dyno. And while TFR has not yet gotten the numbers from the NASCAR Michigan International Speedway tests, we do know that Yates once again was the horsepower king.
GM advanced the disadvantage argument at Bristol. Compared to the Ford teams, that the camshaft sits lower in the GM block than the Ford, by some three-quarters-of-an-inch, which limits cam choices. This argument does have some merit because the GM men deal with a cam that sits closer to the bottom of the “V” (hence the term V8) preventing use of a cam with taller lobes, a machined-in high spot on the camshaft that pushes the pushrod, which in turn opens a valve.
Another disadvantage to the GM block camshaft positioning is the longer pushrods, about three-quarters-of-an-inch longer than the Ford according to garage sources. As the mechanical actuator between the camshaft and the valves if the pushrod does flex or walk a problem is present.
Dodge has little room for complaint since their motor is a custom-built racing engine that was designed on a clean sheet specifically for NASCAR style racing. Since its introduction in late 1999 the Dodge block has carried a huge weight disadvantage, about 40 to 60 pounds, depending on the source. You might recall Dodge’s Ray Evernham’s complaints when he discovered the factory block was bloated, but this disadvantage has its privileges. The block has the best cooling system in the game for both its internal oil and water systems — a choice consciously made by the designers. Weight and cooling issues aside, the Dodge block sports GM SB2-like heads — a design choice not made by Dodge, but rather NASCAR.
The Dodge boys, however, still complain that their motor is unable to make power comparable to the Ford motor. The argument is getting some attention, now, because the motors in Evernham’s cars have turned lower than expected numbers in the last two NASCAR dyno tests. But, even when Evernham was with Hendrick Motorsports, and the motor was housed in a race-winning car, at times the engine tested lower than expected.
The chassis dyno can introduce errors in measurement due to varying temperatures in driveline coolants. But switches in the driver’s compartment that run the car off the alternative distributor cam, the one that’s 4 degrees retarded, can also be activated and make a horsepower reading appear low. Dodge might argue valve geometry, pushrods an inch shorter than the Ford motor uses, prevents turning comparable RPM levels. But that was a choice Dodge made when they designed their clean sheet P7 motor.
All this rock throwing at the Ford Blue motor casting is directed at the oldest motor in the NASCAR fleet. The Ford engine design dates back to 1992; and has been turned down for factory freshening by NASCAR countless times through the years.
