Abstract: Described is an oil filtration apparatus that includes external vanes 120 and associated outer flow passages 140 for allowing a heat exchange to occur between oil passing therein and cool air that passes by the vanes. A manually rotatable valve 154 is provided at one end of the filtration apparatus for controlling the flow of oil through the manifold. In a first position, the valve allows oil to flow through the outer flow passages through the end cap 152 and into an inner flow passage 142 where it is filtered before flowing through a central passage 134 and out the flow manifold. In a second position, the outer flow passages are blocked so that oil flows directly into the inner flow passage. A pressure sensitive valve 164 is provided in the end cap so that when the filter becomes clogged, oil is diverted directly to the central flow passage bypassing the filter.