Mark Cronquist, Joe Gibbs Racing's head engine builder, and Lake Speed Jr. join Joe Castello on Hidden Horsepower. Mark talks about the design of the JD-1 engine, named after J.D. Gibbs, the drive to stay at the top in NASCAR, experiments that didn't work, oil analysis, and the evolution of racing engine technology. Mark even tells a story about when Jason Line worked at Joe Gibbs Racing.
