MG MGA Fuel Filters / Fuel Regulators BBS discussion at MG-Cars.net

MG MGA - Fuel Filters / Fuel Regulators

Grant I run a Facet fuel pump. The fitting instructions advised fitting a filter/regulator so I fitted a Filter King under the bonnet on the vertical front of the lower firewall where the fuel line enters the engine compartment. All has worked well for many years with my 1800 engine so I presume it's doing its job. Mine is a solid type regulator, similar to attached image. Steve

Steve Gyles

Filter King makes various models of filter-regulators, and any of them may be overkill for the MGA. The only reason you need a pressure regulator is if you have an aftermarket fuel pump that puts out too much pressure. Pressure in the range of 1.5 to 4.5 psi is acceptable. The MGA was built originally with no fuel filter. It has (had) a pencil size bug screen in the fuel pump, and thimble size screens in the carburetor float covers. The idea is to catch particles that might be too large to pass through the float valves or main jets. Original type float valves are very tolerant of small debris, generally "self washing" (but they do fail for other reasons). Gross Jet float valves may be a little less tolerant of medium size debris in the fuel (although they may otherwise last indefinitely with no wear). If you have a dirty fuel tank (and choose to live with it), then you may need a fuel filter. Size for the filter is still not very important, as the smallest filter will pass enough fuel for an stock MG engine. Find one with 1/8-inch-NPT pipe thread ports (optional) and use 5/16-inch hose barbs. If you were particular about being neat you could pipe it into the hard lines. The only size consideration is for how long it may take for the filter to become clogged. A larger filter may last longer between maintenance calls. To this end, if you expect a lot of trash, then even a large filter might get clogged up quicker than you like, which is when it becomes imperative to clean out the fuel tank. If you think you I needed a larger fuel filter, then I would recommend a sediment bulb type filter with the see-through glass bowl and sintered bronze filter inside. See attached picture. The bowl will have capacity to hold lots of sediment while sintered filter element is pretty much self cleansing while being sloshed about with normal vehicle bump and vibration. When it does collect enough sediment, you can R&R the glass bowl to dump and rinse it in about minute without disturbing any of the fuel line connections. The proper trick to keeping crap out of the carburetors is to keep the fuel tank clean. Once the tank is clean, if you drive a lot and flush lots of fuel through the system it should stay clean, and any small sediment will wash right through the fuel system. I have driven my MGA over 222,000 miles in the past 22 years (love those twos), and have never had any fuel clog problems. What the cars don't like is being left in long term storage with less than half a tank of fuel, which is when the tank may rust inside (especially with variable temperature and humidity). It is a big mistake to park it in the fall with one gallon of fuel intending to drain it in the spring. If the fuel is relatively clean the size of the filter (or even the presence of a filter) is pretty much irrelevant. I have been running a finger size filter at the inlet to my aftermarket fuel pump. This filter gets changed when the fuel pump gets changed, every 100,000 miles or so. In other words, my car apparently does not need a fuel filter, but it's there just in case I might ever get a load of crap from a gas station.

Barney Gaylord

This thread was discussed between 14/05/2009 and 15/05/2009

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