Maserati Spin-on Oil Filter Conversion

If your Maserati has a large brass cylinder, usually painted dull orange, hanging from the right lower side of its in-line six engine or from the lower front of an early V-8 engine, the following should be of interest to you. The above mentioned cylinder is a water to oil heat exchanger and also serves as an oil filter housing. You will notice a large diameter hose running from the radiator to the heat exchanger and another one from the heat exchanger to the water pump.

Several problems present themselves to the owner. Just like a radiator, the heat exchanger has a large number of thin tubes through which the engine coolant must flow and like a radiator, these tubes can become clogged with calcium deposits, lumps of old gasket sealer, etc. This condition will of course cause the engine to overheat due to coolant flow restriction. If your Maserati is running hot, having the radiator and heat exchanger -flow checked by a radiator expert may give you the reason. Never put anything but distilled water and quality antifreeze in your Maserati’s cooling system by the way.

The other main problems that can be encountered lie with the oil filtering part of the system. A paper element is employed rather than the more convenient and less messy spin-on filter used on later cars. Although, under normal circumstances, there is no chance of being doused with coolant when replacing the oil filter element since oil and coolant are not mixed together, it can still be a daunting task to avoid the inevitable gush of oil when removing the paper element, installing a new element, keeping the element back-up washers, seals and spring in the correct order, getting the center bolt started without cross threading it and making sure the upper and lower canister seal rings are located properly while several pounds of brass full of engine coolant dangle by 2 pieces of radiator hose.

A word of caution here, and this applies to all cars with canister type filters with replaceable elements. Many well meaning back yard mechanics, like the proverbial baby and the bath water, have caused great damage to their cars’ engines by inadvertently throwing out the important filter back-up washers, seal ring and spring along with the old filter element. Without something to seal the ends of the filter element the dirty oil just bypasses the filter and carries the same dirt and metal particles around and around the engine doing wonders for all those close tolerances. Before installing a new filter, check to make sure all the proper parts are there and in the correct order.

The following is one solution to the above mentioned problems. Go to your local N.A.P.A. auto parts store and ask for Part # 1-7519 which is a sandwich plate to be installed between a spin-on oil filter and a Chevy V-8 engine. Also ask for an A.C. oil filter, part # PF-932, Fram # PH 373 or N.A.P.A. # 1794. In other words, a large capacity, 2 Quart, spin-on oil filter for a 1975 Chevy small block V-8 engine.

The above mentioned sandwich plate will have 2 threaded holes in it, (1/2″ pipe thread), so that you can route the oil to an auxiliary oil cooler.

EXPLODED VIEW OF HEAT EXCHANGER/OIL FILTER ASSEMBLY NOTE: This drawing happens to be from the Ghibli parts manual and is correct. The parts are depicted in the wrong order in some factory illustrations.

(#60) Oil filter cartridge(s). (#61) Filter cartridge back-up washer. (#62) Cartridge to center bolt Rubber 0 ring seal. (#63) Upper spring perch. (#64) Spring. (#65) Rubber 0 ring end seal. (#66) Bottom cover plate. (#67) Center bolt rubber 0 ring end seal. (#68) Center bolt. (#69) Heat exchanger/oil filter canister. (#55) Rubber 0 ring end seal. (#52) Oil filter housing.

by Wil de Groot

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