fuel filter used

[SteveO_71]

Hello,
My 71 has a Holley carburetor, 80457, installed on it with a 3/8 fuel line connected to a banjo fuel inlet with a little debris screen. There is also an inline filter before the fuel pump. Just wondering what type of fuel filter is preferred? Should I remove the banjo fitting / screen and install a screw in filter? Can I put one of the bronze filters in the carb inlet or are those for a compression fitting?
Thanks

[1969_Mach1]

I use an inline fuel filter between the fuel pump and the carb. I don't know exactly why, but I've read with mechanical fuel pumps the filter should be between the pump and carb. Plus, that is where the auto manufacturers always put them on carbureted motors. For my peace of mind I stay away from the type that the rubber hose clamps on to. I don't trust hose clamp fittings on the pressure side of a fuel pump. That's just me. I went through the extra effort of installing an inline fuel filter with #6 AN fittings. I purchased the filter, fittings, and aluminum tubing from Summit Racing. I use #6 AN, which is 3/8".

Best Regards,
Mike

[JTS71 Mach1]

The fuel pressure might cause a problem, except that the mechanical pumps only produce about 5 to 7 psi. So a clamp is more then capable of holding the pressure. You are correct, the filter should be between the pump and the carb, and not before the pump. Just as the mechanical pump has a low output pressure it has an even lower amount of suction, and if the filter were slightly plugged it could cause fuel starvation. It is always easier to push something then it is to pull it. Just some thoughts JTS 71 Mach1

[Mach1FatherFigure]

The fuel filter used on E23 E30 and E32 is HUGE and has simple hose fit ends. I have used them on other vehicles I have owned with no problems.

[1969_Mach1]

I he wants a universal inline filter with 3/8" hose nipples, Wix has one, p/n 33033. Wix has one of the best quality oil and air filters. I imagine their fuel filters are the same.

Best Regards,
Mike

[SteveO_71]

Was the Holley a carb someone added later? I thought the 71 Mach 1's came with an Autolite or not?
I can understand not having a pre pump filter but when I removed the pre pump one that is currently on the car, it was really filled with junk. I would hate the thought of all of that crud going into the pump. Can I still have the pre pump filter and then one from pump to the carb or is that really overkill?
What was done originally?

Thanks

[JTS71 Mach1]

Originally if your car was a 2 barrel carb it was definitely an Autolite Carb. I'm not sure about the 4 barrel carbs? The factory only used 1 fuel filter on the 2 barrel carbs it screwed into the right lower corner of the carb itself. There have been several different setups, depending on what "carbs" were used most had the inline filter in the line from the fuel pump to the carb about 3/4 the way up the line, and it was the slip on hoses and clamp style. The filter before the pump being full of trash, indicates a very old, dirty /rusty, fuel tank and somebody's bandaid over the problem. Sounds like time to clean the tank or replace it if it's really bad. The 2 filter idea would definitely be overkill, and could cause starvation as you could have to much restriction. Hope it helps JTS 71 Mach1

[1969_Mach1]

There should be a screen filter on the end of the pick up tube inside the fuel tank to stop big stuff from coming out of your tank. It sounds like it may be missing and your car is ready for new steel fuel lines and clean or replace the fuel tank. The fuel lines are relatively inexpensive. I would change those, if a new tank is out of budget clean it as best possible, and put a new screen filter on the pick-up tube inside the fuel tank. Bottom line, clean the fuel system as best you and your budget will tolerate.

Not to scare you, but its possible that eventually, some small particles will make it to the carb and can cause the needle and seat to stick open, flooding the engine and leaving you stranded. From personal experience, that's not fun. I had a 1956 Ford Pick-Up that had that same issue. At the time replacement tanks were not available. I had two in-line fuel filters on it, one before and one after the pump. But occasionally crud would get into the needle and seat. The smaller particle can get into the passages of the metering block as well causing issues.

My neighbor currently has a 65 Fastback with that issue. There was a bunch of crud in the float bowls on his Holley carb when I rebuilt it. He rarely drives the car and his filter still plugs fast. He as been fortunate and not experienced the carb flooding issue yet.

Clean the fuel system.

Best Regards,
Mike