Hi Baz
I had the same problem with my 1.8 Zetec & have fitted an oil filter from an early OHV Fiesta.
Just been out to measure & it is aproximately 80mm in length .... Can't read the part number because as sods law says, it is underneath
Any short oil fiter with a 3/4" BSP thread should do the trick ( Assuming the OD is suitable )
