When rebuilding my 1936 12hp tourer (completed in 2001) I fitted an AC bypass oil filter, but I removed it after 2000 miles as I could not source a replacement. However, the micro-filtration properties of this type of filter are attractive and this year I searched the web for a modern equivalent. I came up with Kleenoil Code 9758 Engine Micro Filter Unit, which consists of a very robust aluminium canister 3" in diameter and 6 1/4" high, holding replaceable paper cartridges (Code 1858).

I decided to mount the Kleenoil filter on the scuttle, held by the bracket supplied, next to the coil. I was advised that the filter would work in any position, specifically that mounting it upside-down would not be a problem. I find that only an eggcupful of oil drains away after use, but to prevent this I have recently fitted a tap.

I fitted a 7" inlet pipe (-04 JIC 20TPI female thread) to the take-off point for the oil pressure gauge on the engine block. The gauge itself now comes off a tee just below the filter.

The return pipe from the bypass filter would normally go into the centre of the rear tappet cover plate, but in my case I had previously drilled and tapped into the block just above the oil filler.

With a bypass system it is crucial that the amount of oil passing through is strictly limited, since there would otherwise be a significant drop in oil pressure. The filter comes with a built-in restrictor and I find that oil pressure is well maintained at 30psi or above, according to Rover specification. In the course of time all oil will in theory be filtered and it should therefore be possible to decrease the frequency of oil changes. I am now planning to carry out an oil change every 2000 miles instead of the recommended 1000 miles, replacing the filter element at the same time.
Ordering details:
Kleenoil Filtration Ltd.
Unit A The Maltings, Fenton Lane
Sherburn in Elmet
West Yorkshire
LS25 6EZ.
Tel. 01977 682810
Website: kleenoil.co.uk
Contact Paul Kitching for helpful advice on fitting to Rovers (e.g. hose length, threads, etc.
Code 9758 Engine Micro Filter Unit. For Engines with Sump Capacity of 3 gal / 16 litres with tight space. Was £100
Code 1858 Micro Cartridge. Supplied as a carton of 6, together with custom hoses, T-piece and adapters. Was £65