an4 or an6 for fuel line

[rollingthunder]

Would an4 be suffiecient for a fuel line?

 

[adam]

No. That's only 1/4". Use #6 (3/8")
If you weren't aware, AN #'s refer to 16ths of an inch. #4=4/16, #6=6/16, etc...

 

[RPM]

Would an4 be suffiecient for a fuel line?

Depends on the fuel demands of the engine. For a low HP engine it would be fine. Most all of the early cars had a 5/16 fuel line. Also the needle inside the carb only has an opening of about .080"

 

[NitroJohnny]

What RPM said. It depends on what your doing with the motor. Low rev driver, 4 is ok. Big carbed big motor thats going to be run hard go bigger.

 

[Old Iron]

I wouldn't go any smaller than 5/16.
3/8 is the best all around size cause, you can upgrade the engine, when you want, without changing the fuel line.

 

[rollingthunder]

Ok cool..ill go an6.. Im runnin a 355 with a 3x2

 

[rollingthunder]

Well I just realized my outlet on the spun tank is only 1/4.. will 3/8 line give more delivery even though there a 1/4 spot on the sytem?

 

[donsrods]

Well I just realized my outlet on the spun tank is only 1/4.. will 3/8 line give more delivery even though there a 1/4 spot on the sytem?

That is tough to say. Short answer would be that no, the fuel line can only feed what fuel is allowed to pass through the smallest opening. But, there are other factors involved, like can your fuel pump suck enough gas through that opening so that the line size doesn't matter. Or, for short bursts there may be enough fuel in the line to supply the motor with all the gas that is already in the 3/8 line and not starve the motor.

If you look at the typical fuel hose barb it will reduce the inside diameter down a lot over the 3/8 diameter of the hose itself, and those work fine. And I assume when you say your outlet is 1/4 that you mean 1/4 npt (natl pipe thread) so that is pretty large actually.

Don

 

[rollingthunder]

ok thanks don.. That makes sense 3/8 its !!! Short bursts