I'm beginning to piece together the fuel system for my street/strip 66 Dart. It'll eventually have a 600-650hp stroked big block.

After thinking about it some, the pump and filter would be near the fuel cell on the frame rail, running to the carb via 1/2" aluminum hard line, then to a bypass regulator and finally returning to the cell via another 1/2" aluminum hard line.

Would this fuel system be adequate? I already have many of the pieces. Is there anything you would change (parts, or hose/line sizing)?

Thanks!

I don't remember how much pressure that fuel pump makes but I would want the fuel regulator in line in front of the carb. and the second fuel filter to be 10 microns mounted between the regulator and carb.
I have used one of the Mallory 140 pumps with the regulator that Mallory sold with it and it was marginal on a smaller 440 bracket motor under 600 HP
Maybe a better, bigger pump is needed now instead of finding out later it isn't good enough

If you're running 1/2" why would you put that piece of 3/8" between the filter and the pump? The regulator needs to be in front of the carb and -6 is fine to the carb. -6 would also be fine for the return. That system will be fine for the street but a 10 sec. car will probably zero the gauge going down the track.

Thanks for the input Cab. Since I have the pump already, I'll probably give it a try and, if it's inadequate, I'll sell it and swap to a bigger pump. Thanks again.


Are you referring to the piece of -8 to supply the pump? Should I step that up to -10?


Thanks for the input. So, placing the regulator in front of the carb would be better. I've always thought after the carb is best since it keeps fresh (cooler) fuel feeding the carburetor, especially in a street car. When at the track, does it not regulate pressure as well in that configuration? Thanks again.

looks like the way you have it drawn, the regulator will only regulate pressure in the return line, carb will see full pump pressure...


EDIT: oh nvm, did some quick reading, seems the pressure is constant in the whole fuel system no matter where the regulator is.

That drawing should work perfectly. Sizes and placement of the regulator are fine assuming using the correct regulator. Much more flow to the carb with this set up. You would possibly be better off with -10 between the filter and pump.

I don't think that's going to work, you're going to have full fuel pump pressure at the carburetor that way. The regulator needs to be moved.

Looks good to me, I would use #10 between filter and pump. I ran a very similar set up for many years, went 9.60s with it in a 3400 lb car. People don't understand that it is designed to keep 7 lbs of pressure in front of regulator.(or whatever you set it to) It won't see high pressure like they think. It was the most steady pressure system I ever had on my car.

you have the regulator in the correct place for a return system !!!

I have & do run this set up like your picture.

With the way you have it drawn in the pic is the way you should do it, just change the short line between the filter and fuel pump, make it bigger. The pressure is going to be the same from the regulator back to the pump.

The system looks fine... the #8 before the pump I
might change to a #10... make sure the filter will
flow the amount needed.. other than those little
things your fine.. on the section of #8 I just like
to have the first restriction at/or near the carb...
as for the pump.. rule of thumb is .5 pounds per HP
and your safe

I thought -8 was the AN equivalent to 1/2" OD tube. Wouldn't hurt to go bigger it is probably fine.

#8 is equal to 1/2"... 3/8" is a #6

absolutly agree, I switched to that system several years ago and has worked flawless every since, just change that smaller line between the filter and pump and you will be golden.

My
I would use a 100 micron strainer in the outlet fitting in your fuel cell and do away with the 100 micron housing because you want a smooth flow of gas to the pump. A filter housing on the inlet side of the pump is not a good idea because it interrupts smooth gas flow to the pump and can cause cavatation. If you do use it keep it away from the pump so the gas has time to smooth out before getting to the pump. It really is a bad idea, a separate pre filter. Just more places for the fuel to heat up and weighs more too.

Use at least all #10 to the pump with #12 being better on the suction side. Minimize any restrictions(smooth fittings and try not to use 90s. Or at least tube 90s) on the inlet side and the fuel pump must be lower than the fuel cell. Can't suck up hill or even level can cause cavatation.

Pressure regulator is in the right place and you only need #6 coming out of the pump. It is a disadvantage to have it oversize because it makes the pump work harder pushing it forward under hard acceleration. It weighs more and then there is slower fuel flow which allows it to heat up more.

This is one kind of 100 micron discharge fitting for your fuel cell, way better than a external filter and housing. Less to heat up like I said. LINK

A fuel pump in the fuel cell is the best way to go.

I favor fuel systems that don't run a return from the regulator all the way back down the length of the car. My Magnafuel pump has the return right at the pump, and no return from the engine compartment. I'm not a fan of running two lengths of hose that distance; waste of money on line, and just another thing that could leak/dry rot/get hit and send you home early. Obviously depends on what parts you already have in your possession.

By returning fuel right in front of the pump you run the risk of introducing bubbles and turbulence into the inlet of the fuel pump and can cause cavatation during hot weather.
Steel line should be used front to back and not hose.

Thanks for all the input guys. I appreciate it. The main reason for the -8 line between the filter and pump was just for packaging purposes. -8 seems to bend a lot easier and the fittings are smaller, so I could pump the pump and filter closer together. Plus, since the threads on both the pump and filter are pretty small (3/8 npt), I didn't realize the -8 would causes much of a restriction. I'll go with -10 though as you folks suggested and separate the filter and pump a little more to make it doable.

Thanks again.

I'll use a return system any day.. when I was
testing hot fuel in Cali.(Death Valley and Baker
grade) I seen fuel temps in the low 300* range..
that fuel at the injectors was sitting there
boiling.. it took a fair amount of time to get
that hot fuel out of there.. with a return it
would be out of there in short order...I dont
mind paying more for a good system.. even if it
weighs more