New GM engine not quite ready

GM's new R07 engine may not be ready for prime time. Introduced last fall, the new engine is the first to be designed specifically for racing by GM. It was touted as the being the successor to the production-based engines that had been used by GM in stock car racing since the mid-1950s. In using what is referred to as a "clean sheet of paper" while designing the engine, GM's engineers were confident they had addressed the kinds of issues that plagued previous designs, in turn building a race-ready powerplant. However, the planned rollout of the new engine into Nextel Cup competition, which originally was slated for sometime later this month or in April, has been delayed. When asked to comment on the delay, GM Racing program manager Pat Suhy said that teams were still testing the new engine and were not yet comfortable with giving up their current engine, the very reliable SB2 – which won its first race when Dale Earnhardt took it to victory lane at the season-opening Daytona 500 in 1998. Although the new engine has not seen a lap of real competition, teams are able to simulate the stresses of a race weekend on their shop dynamometers, which are used to measure power and durability of engines. Those tests include running the engines until they are hot, letting them cool down and then heating them up again, which is known as heat cycling. What teams have found hasn't been all that comforting. "We've blown at least one of them up," said one senior team member who asked to remain anonymous. He did stress that failures do occur whenever teams work on something totally new. And, he added, he expects Chevy teams will continue to test the new engine, including on actual race weekends. Yahoo Sports