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Fuel line internal diameter

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tao724

Jedi Trainee
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Sorting through my new fuel pump, filter, copper lines, and rubber hose before a trial fitment, I notice the Facet fuel pump supplied barbed connector ends seem to be for 5/16 hose, and indeed the hose is 5/16. Sorting through my new Automec fuel line kit, I notice everything appears to be 1/4, (copper line and rubber hose). Checking the inlet piece to the SU's, they fit the 1/4 Automec hose. The common plastic fuel filters in the catalogs have 'reducer ends' to accomodate both sizes. My question is...........is there an inline 'reducer' connector piece available to go from 1/4 to 5/16, from tank copper line to hose to pump, then 5/16 to 1/4 from pump to copper line to hose to carb? Or, do I just 'muscle the 1/4 hose onto the pump connectors? And double clamp the 5/16 hose onto the 1/4 copper line? Is this a common situation?
Thanks
 
1/4 inch is the standard on our Spridgets.

Check with your auto supplier, all sizes of connectors are available.
 
I just did this job last week. Throw the fittings which come with the Facet pump in the spare parts jar. Replace the 5/16" diameter push on tubes with threads with 1/4" tubes which screw into the Facet. Get these at the Hardware or auto parts store. I used fuel injection 1/4" I.D. tube ($$) and spring clamps to connect the rigid hoses with the plastic fuel filter to the pump. I used the same flex tubing at the other end to connect the 1/4" tube to the carbs and then between the carbs. I have not been able to find the correct tube between the carbs with what looks like SS covering. Hope this helps.
Scott in CA
 
That is correct according to my memory. However, you can google AN size or what ever and get a table that gives the sizes in good old US numbers.

AN Dash Size Nominal Equivalent Hose I.D.
3 3/16" 1/8"
4 1/4" 7/32"
6 3/8" 11/32"
8 1/2" 7/16"
10 5/8" 9/16"
12 3/4" 11/16"
16 1" 7/8"

https://www.russellperformance.com/tech_center/manualorigin.htm
 
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