Your car’s performance depends on precise control of air, fuel, and spark, and vacuum leaks quietly disrupt that balance.

One of the most difficult tuning problems to overcome is the seemingly ever-present engine vacuum leak. Vacuum is an important component of the internal-combustion process because it controls basic ...

Carl Arentz bought his 1964 Chevelle two years ago, well used but running. "I'm well aware that it's an old dog that should have been put down," he says, "but I can't bear to see these cars go to the ...