[Jacques Reed]

Hi Mariano,

Your diagram shows a factory full flow oil filter set up. I have never seen that relief valve setup other than in diagrams. Every WW2 Flathead V8 that I have seen in Australia has the bypass type filter. Hot rodders have for years modified the system on Flatheads to incorporate a full flow oil filter utilizing those three inlet/outlets.

Most early factory Ford flathead oil filter setups are the bypass type. This type does not filter all the oil but only a small proportion of it which is returned to the sump (i.e. oil pan) from the filter outlet.

The inlet orifice size on the bypass type oil filter container is critical to maintaining oil pressure within the system. Under no circumstances should it be enlarged in the belief it will filter a larger volume of oil. to do so would cause a substantial drop in oil pressure in the system.

Would be curious to know if anyone has one of those relief valves.

Cheers,