5/16" id or 3/8" id fuel hose?
 

Getting ready to add a fuel pressure regulator to my stock 8ba motor and a 94 EAB carb and will replace all rubber fuel hoses. I have 3/8" from other projects but I'm sure this combination would be fine with 5/16" but since it's going to be apart I figured I would ask the experts here.
Does it matter either way? THANKS GUYS!

Re: 5/16" id or 3/8" id fuel hose?
 

Call me old fashioned but 1/4" would be enough.

Re: 5/16" id or 3/8" id fuel hose?
 

From my days as a sprinkler tech at a local country club golf course the further the distance and bigger diameter the more pressure drop. I would think that 5/16 gives you the lesser "potential" of decrease in pressure BUT at that short of distance it most likely would have little to no effect.

Re: 5/16" id or 3/8" id fuel hose?
 

If you can go with 1/4 inch to keep it all the same.
I am assuming rest of your fuel line from the tank is OEM 1/4 inch.
Use the hose that is intended for today's gas.
https://mossmotors.com/barricadetm-e...-hose-by-gates

Re: 5/16" id or 3/8" id fuel hose?
 

I hate to disagree but the bigger the diameter the less the pressure drop.

Charlie Stephens

Re: 5/16" id or 3/8" id fuel hose?
 

Pressure drop is not an issue with the pressures, flow rates and distances we are dealing with.

Re: 5/16" id or 3/8" id fuel hose?
 

The slower the fuel flows through the larger size helps promote vapor lock. Go with small

Re: 5/16" id or 3/8" id fuel hose?
 

Too small diameter can cause restricted fuel flow ( starvation) , some times fuel hose will grow shut, seen it many times on heavy equipment, maybe just the type of material, the only time I use 1/4'' is on small lawn mower engines. Just my opinion.

Re: 5/16" id or 3/8" id fuel hose?
 

At stock horsepower levels, you can run 1/4, 5/16, 3/8 - whatever you like. Truth be told, the 1/4" line will feed more fuel than you'll ever use.

Re: 5/16" id or 3/8" id fuel hose?
 

Thank you for all your replies. And thanks for the fuel hose link for the good hose.

Re: 5/16" id or 3/8" id fuel hose?
 

I run 1/4 inch fuel line with a 390 Holley and electric fuel pump on a flat head with a fuel regulator near the engine. No problems.

Re: 5/16" id or 3/8" id fuel hose?
 

This is good info to know , I am guilty of overkill, sometimes I forget we are working on flatheads and see more and more of why henry designed them the way he did.

Re: 5/16" id or 3/8" id fuel hose?
 

original hard fuel line was about 1/4" correct?

Re: 5/16" id or 3/8" id fuel hose?
 

The original hard line was 1/4". That's OD so the ID was more like 3/16". So 1/4" bore rubber pipe should be easily adequate.

Re: 5/16" id or 3/8" id fuel hose?
 

Thats what I figured, thanks Mart!

Re: 5/16" id or 3/8" id fuel hose?
 

what size comes out of the tank thats it you cant draw any more but remember there a low pressure engine 2/4 psi