jay

Anyone know what size the stock fuel line is (from the back to the front of the car) ? I burned up my Holley blue, it was only about a year old and low miles. I'm thinking the fuel line might be too small? I'm replacing it this weekend with the Mallory from RB. Do I need to run a larger diameter line? I hope not. My car is a 79 with RB Holley carb set up w/ Holley regulater set at 6psi.
Any help would be helpful. Can't afford to replace fuel pumps once a year @ $160 plus the reliability. Thanks in advance

mikewoodkozar

Larger fuel line is recommended i think i used 5/16" or 3/8" I dont remember what size actually only that it was larger

redbstd

Also were do you have the pump located? it needs to be level or below the tank and close to it. pumps are better at pushing than pulling.

jay

So is the stock fuel line 1/4"? or 5/16"? My fuel pump is mounted level on the frame rail hump, it is dead nuts perpendicular to the ground. It's just below the tank and just below where the fuel filter is on a 79. The question is - do I need to run a new (larger line) under the car in order to eliminate burning up pump motors. If so - what have some of you gurus done. I assume metal lines would be better huh. Thanks again

1BADSP

iTrader: (4)

i run 1/2 in O.D.fuel line from the in tank pickup to the regulator,from the regulator to the carb i run -6 aeroquip,i have never run out of fuel,but i have had fuel pumps quit after sitting over the winter.

Clearkut

iTrader: (1)

I belive the stock lines have a 5/16 main, and 1/4 return, I replaced mine with 3/8 main/return all the way into to the tank, malory pumps would only last 10k km for me. I was ussing comp 110 malory pumps, ther very quiet, and very smooth fuel delivery, but too expensive to burn out every year,I went through 2 this past summer alone(one was a free replacement) and I burnt out one the prior summer!! threy quit almost to the km very reliable to that point but just stopped working, I recently replace the malory with a carter, the carter is loud, and i have only put 200km on my carter before the car was stored for the winter so i dont know how it will last, but it was only 1/3 the price of the malory so I can deal with the noise
What malory are you planning on using, 70/110

jay

I just got the Series 70 to replace the Holley Blue that burned up(it got so hot it melted the wires together where they come out the motor). I don't have the return line in use since I switched to aftermarket pumps, not sure if thats partly why the Holley burned up or what. The mallory recomends using 5/16 or larger, if the stock is 5/16 then it should be OK. I think Holley recommends 3/8" line.

trochoid

iTrader: (6)

If you want longer life out of your Mallory, run 3/8", supply and return. They do not like non-return systems. I bought a 25' roll of AL line for about 20 bucks at the local speed shop. Be sure to bulb the ends of you lines where you clamp rubber hoses.

Clearkut

iTrader: (1)

use the mallory bypass style regulator(iirc part #3909), it will let you set up a return system and dial your pressure to desired psi.

I did the same but with stainless steel lines, what a B!TCH to bend, but should last forever