Thread: Where does my second fuel filter go???

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Originally Posted by IC2

While you can (should??) put a non restrictve filter before the mechanical pump, there should always be one between it and the carb.

With an electric pump you are first trying to protect that tight clearanced rotor then secondarily the carb. The mechanical pump valves can tolerate some level of dirt so here your primary objective is to protect the carb (does that make sense)

Yes thanks!

So it looks like I need another filter between the mechanical pump and the carb. It is going to be interesting to prime that system so I don't have to crank the engine a lot on the first start. Maybe a suction bulb wil pull gas through all of that restriction. On a previous car (MG midget) I had a whole box full of plastic see-through filters with small paper filters inside and they flowed pretty good. They were just inserted in the fuel line before the carb and held with clips; I changed them frequently due to a rusty gas tank but I could see if anything was in there. With my first filter shown above I would think the gas should be pretty clean after the first few minutes flushing the new line. Now I have to rethink another filter.

Don Shillady
Retired Scientist/teen rodder

I have a Fram the same size as Don's located just ahead of the fuel cell. The question I have is, why does every one have so many filters? One would think the large canster filter would be "overkill" as years past saw only a glass sediment bowl, and I am sure there was more trash in the old tanks.

Originally Posted by John Brian

I have a Fram the same size as Don's located just ahead of the fuel cell. The question I have is, why does every one have so many filters? One would think the large canster filter would be "overkill" as years past saw only a glass sediment bowl, and I am sure there was more trash in the old tanks.

I use two filters because of all the junk in fuel these days.... I don't know if it's because of additives at the refinery, careless fuel transfer, or poorly maintained tanks but there is a lot of contaminents in the fuel.... If it sits in the tank for any amount of time, things get even worse..... It doesn't take much to upset the performance of an engine..... The cars with the sediment bowls usually ran an old Rochester or Carter carb, the Holley's and Edelbrocks that a lot of people use now are way more intricate and have more systems withing the carb, thus being more sensitive to contaminents.

For me, the extra filtration is somewhat comparable to an insurance policy, maybe not all the fuel I buy is junk, but if the extra filter prevents messing up the carb one time (usually happens during the final round or many miles from home) it pays for itself......

Besides it looks cool!

Both Dave S and Stovens have the right answer.

I originally built my car to run with an electric fuel pump and had the primary filter mounted on the frame just before the pump and a little one in the line before the carb. I converted to a mechanical pump (not really ea$y on a $B Ford - if it has the wrong timing cover). I did away with the canister filter and am now using a 40micron Speedway race car type unit.

This one