This oil cooler is a replacement radiator for the engine oil circuit. It sits in the oil loop between the engine block and the oil filter housing, dissipating heat from the oil before it returns to the sump. Maintaining proper oil temperature is critical for correct viscosity and lubrication of the crankshaft and bearing surfaces. A cooler with reduced flow capacity or internal blockage will cause oil temperature to rise, leading to reduced film strength and accelerated bearing wear. The manufacturer machines the core and mounting flanges to match the original assembly's port alignment, so no adapter hoses are needed on installation. Replace the O-rings at the ports when reinstalling.