A more serious problem was that of overheating. Piston temperatures in particular were troubling. Nicolae Glaja, a Romanian-born engineer, initially tackled the problem by installing oil jets in the crankcase, aimed so that they sprayed the piston crown from underneath. While this cooled the pistons, the oil temperature then became intolerably high. Skip Metz, engineering project leader for the engine, and his team then came up with installation of an oil cooler, with good results. However, the styling and marketing departments felt that this fix looked too much like a band-aid solution. It seemed to be an admission that Harley-Davidson had designed an engine that ran too hot. Management agreed, and the 1998 release date was also passed. Returning to the drawing board, the engineers examined the entire oil system. The excessive oil temperature was not just the result of heat coming from the piston crowns, but from the cylinder head and rocker boxes. Engineer Ben Vandenhoeven then initiated a series of test runs restricting oil flow to specific areas of the engine, with surprising results. In the initial design the concept was that flowing large amounts of oil through the rocker boxes (much more than was actually needed for lubrication) would help cool the heads. In actuality, not much cooling was provided for the heads. Rather, the heads were heating the oil. The oil flow to the rocker boxes was cut down to about one-sixth of the initial design flow, still adequate for lubrication, and this brought the operating oil temperatures to around 220 degrees. The engines were released for the 1999 model year. High operating temperatures have continued to plague the Twin Cam engines, although the engineering refinements have resulted in a reliable and smooth-running engine.