We're just finishing putting our duratec back together on which in the past we have always used a straight forward CVH oil filter (we have a remote mounting).

However this time my father unknowingly picked up a ford filter with a non return valve in it. This filter when connected to our engine (piped up exactly as we have been running it for the past 2 years) does not allow oil through it. Now this is obviously because the filter is designed to flow the other way and so the non return valve is preventing flow.

So, currently our oil flow TO the filter is coming out of the middle port on the remote filter housing - so feeding into the center of the filter and then returning to the block via the outer holes of the filter. So given we swap back to a bog standard filter is this ok or should it be flowing to the outside of the filter and then returning out of the middle hole in the filter?

Does it even matter? I would assume that the filters are designed to 'store' the filtered debris so perhaps it does? Im sure I looked into this when piping the remote housing originally but I really cant remember....

i would have thought the unfiltered oil goes to the outside, and the filtered oil comes out the middle of the filter.
outside of the filter element has a larger surface area, more volume to store bits, and so should last longer. thats how i fit any kind of filter anyway

Flow goes from the outside in , many filter types ( including the Ford Pinto) have a rubber one-way valve to prevent oil draining back to the sump when the engine is stopped.

[Edited on 1/8/12 by britishtrident]

Hi Dan

Did a quick search on Google "how oil filters work"

and the images seem to support what blakep82 says. ie oil from engine goes into the outer holes and is then returned via the hole in the centre.

Thanks guys - yes I should have googled! Looks like we've had it the wrong way round

It can matter... The Pressure relief valves apparently open at higher revs as the filters are not large enough to allow the flows;this will get worse as the filter is loaded during it's life. I guess non original filters (i.e. the sorter ones!) might have less filter area and may suffer from this more. So at higher revs the oil can pass unfiltered.. This means if you plume in backwards you might find you have poor oil pressure after the filter at high revs..

Dan

[Edited on 1/8/12 by Bluemoon]