Toyota Racing Development, provider of engines for the Toyotas of Michael Waltrip Racing, Robby Gordon Motorsports, and Red Bull Racing, has decided to revert back to the oil pump used on TRD engines last year, and will continue the modifications used in the Shelby 427 last week at Las Vegas Motor Speedway.
In the last two weeks, TRD had to replace six engines due to lifter or camshaft issues . Lee White, TRD president, believes the issue has to do with oil pressure when the cars are in low-RPM situations.
It is also believed that the better tire at LVMS increased lap speeds by three-quarters of a second, which may have led to more strain on the engines.
TRD has switched to a more aggressive camshaft that uses a lighter weight oil.