Thermal Expansion Measurements on Operating Automobile Engines

As today's automobile engine become more sophisticated the need to perform additional testing becomes essential. Many components now serve several purposes in order to produce higher horsepower in a smaller overall package. This requires each component to be manufactured to tighter tolerances. An example would be the oil pan. For years the sole purpose of the oil pan was to act as a reservoir for the engine lubricant. Some modern engines now utilize the pan as a structural component. It is machined from a rigid steel or aluminum casting and designed to support the lower portion of the crankshaft bearings and rear main seal. This development has introduced a potential problem area that must be analyzed. As engines go through heating and cooling cycles it is essential that the engine block and oil pan expand and contract at nearly the same rate. If not, stresses can be introduced to the pan gasket, main seal and bearing races. This can cause oil leaks, premature bearing failures and unwanted noise and vibration.