Bypass oil filter on car or tractor

For those who may not know, a bypass filter is one that is supplied with a small volume of oil processed through the filter media and returned back to the crankcase at zero pressure. It is never part of the pressurized lubrication system. Bypass filtration bypasses the high volume full flow oil circuit. Someone stated that they would install the bypass in line with the full flow filter. Doing that would not work as the bypass filter head has a very small orifice to reduce the flow through the bypass filter. Thus, it would starve the main oil rifle passage (oil gallery) and destroy the engine. It is correct that this type of filter system needs sufficient oil pump volume to be able to spare a small volume of the oil to be diverted away from main engine lubrication. Some diesel truck engines (18 wheel) have bypass systems that operate on 2 GPM maximum flow. Engines of that size can spare that volume without jeopardizing the lubrication requirements of the engine. To install such a system on a small diesel or gasoline engine would require a much smaller control orifice to prevent oil starvation of the main full flow filter.

Thankyou for the best description of a bypass filter I have ever read! Having clean oil is the goal, long oil live is an added benefit. I appreciate you taking the time to post.