Technical Changing 1/4" fuel line to 3/8'"

Where D Go?

 

I'd look at it like this:
How hard is it going to be to replace the line on a finished car IF you do have a problem
..................................................................VS.........................................................................................
How hard is it going to be to install a 3/8 line from the git go

I'd put an electric fuel pump in the tank with an access panel in the trunk for easy servicing. Then a under car filter in line and a pressure regulator up forward with a an electrical pressure guage for easy reference and troubleshooting. Then maybe another small filter before the carb.
Then you know you have plenty of flow and pressure and its not a headache you have to sort out later.
Do it right....do it once. Make a miscalculation and do it again. I learned the hard way!

 

I almost used the name John Meeoff..aka Jack. But thought better of it in 2006.

 

3/8 may be overkill for most, but my avatar has a blown injected hemi, so need all i can get

 

Sometimes when going to larger line you are actually creating a fuel reservoir, it gives your pump more free flowing fuel to draw from. It won't work really well on a long run but makes all the difference in the world in about 1320 feet or less.

if you want to do something that makes a difference for longer distances at higher fuel demand you have to open up the fitting. One some tanks there is enough meat in the original fitting to drill and tap it. In others tanks the original fitting needs to be drilled out and a new one soldered in. You can solder an old tank, if you are using a soldering iron and not an open flame.

Now as for the screen name, I actually thought about Johnny Fukerfaster, I could have probably pulled it off when I joined. My name unfortunately is not johnny and I do not like using my real last name on the web.

 

You guys covered it, modify the pickup for larger line, or buy the expensive premade one, run 3/8 line.

@Howie Feltersnatch what do you need AN line for ? 3/8 hard line from tank to engine mounted fuel pump, hard line from fuel pump to carb.

I ran low 12's all day with GM fuel pump on a small block chevy, don't overcomplicate it.
There an engine masters (check you tube) where they test mechanical fuel pumps, very good info on power levels with pumps on the market.

 

Howie has not been seen since his post in March. I’m guessing it was his real name but what do I know. Phil Macraken, Ben Dover, Dillon Pickle and Richard Head have also left the building.

 

Talking only basics. It’s not the 1/4” line that’s the issue, it’s it length that causes flow restriction. So if a step up fitting at the tank has a larger I.D. dimension than the main jets combined is there a restriction?

 

Oh, I get it now; Howhe Felthersnatch. Very amusing in a tweensian/pre-pubescent, boys locker room, 18 year old virgin, sexual angst sort of humor.

 

It's a bit of both - the diameter of the line, and the length of it, all contribute to the pressure loss.

A 600 mile length of 1/4" line is a lot harder to get fluid through than a 6" length of line (pressure drop through length)... but a very short "pill" in a fuel injection setup makes a huge difference to fuel flow (pressure drop through orifice size).

Cheers,
Harv

 

Actually, I think thats the point. A 1/4 line has more resistance thru its length than a 3/8 will have thru its length. Increasing the size of the fitting at the tank will not change anything........my opinion for what its worth.