Fuel Line Hard or Flex Line.

[Cyclone03]

I'm just racking my brain on this one.

I have an FE Mustang about 500HP,I want to keep the fuel as cool as posible,front to back.
I'm running 1/2 Stainless Hard line now from the tank to a short section of Push Lock tubing to the Block Mounted pump,then filter then regulator and carb.

My plan is to replace the block mounted pump with an electric near the tank.
I was thinking of using this Stainless PTFE lined hose...

http://www.frozenboost.com/product_info.php?cPath=219&products_id=1241&osCsid=5919e916eeae737587d1147046eaf1b3

Front to back with a return.
The reason for the PTFE tubing is I want to limit the gas smell in my garage and prepare for Fuel Injection.

[A/Fuel]

I read this post the other day and really couldn't figure out what you where really trying to ask.

[Cyclone03]

Hell I'm not sure what I'm trying to say either.....

Hard line front to back or teflon lined braided steel?

The reason for the teflon hose is to get the !@#$%%^ gas smell out of my garage. The hose I'm using now smells of gas on the OUTSIDE.

On one hand I can just add a secound Stainless Hard line for a return then mate the ends with the above hose.
On the other run the above hose front to back,yes I want the lines to match so return and feed must be the same.

The side project is to try and keep the fuel cool,The closest the lines get to exhaust is about 3" at the rear frame rail,then runs along the body pinch flange then back to the front wheel well,into the engine compartment,pump,filter,carb.Basicly it's stock 68 Mustang routing.

I'm thinking the Hard line may keep the fuel warmer than the braided hose but in the end how much does it matter?

[CTX-SLPR]

No real experience but go hardline for as much as you can bend on your own or buy prebent in the correct size for your needs. Braided stuff is for stuff that has relative motion, you can't bend a single piece/get to the union easily, or needs to come apart frequently. When you do run the braided stuff, by all means go for the teflon lined stuff so today's fuels don't eat it alive.

[SpiderGearsMan]

I ran 12 feet of -8 aeroquip hose , not cheap

[BKBridges]

Ive had good success with nylon lines with kevlar braid over them. Good heat rejection and very inexpensive Dorman's EFi line kit runs about 150.00 and has enough stuff to do about 4 cars. The Kevlar braid comes from McMaster Carr. The down side is aesthtically they dont really pull it off...The pic is of my 72 Baccaruda. Ive got about 20K miles on the conversion/fuel lines with no issues. Most of the fuel heating happens in the fuel rails in the engine compartment. The return line sends the hot fuel back to the tank and heats up the whole tank. Running the regulator under the car right after the filter, keeping the return line out of the engine compartment helps a lot. The down side of that is no air purging in the fuel rails (debateable but a concern). Insulating the fuel rails with silica felt can help reject the fuel heating, but again, aesthetics come into play.
Bruce

[Scott Liggett]

I've never experienced a "fuel smell" standing next to a car when the system doesn't have a leak somewhere. Two of my cars have a vent tube going up into the trunk and back out and neither smell of fuel. I'd check for a cracked line or a leak somewhere. Fuel smell means fuel vapors. That is what burns and explodes.

Also, why the worry about heated fuel? An electric fuel pump will heat up the fuel as the fuel moving through is what keep the electric motor from overheating. Moroso used to make a Cool Can that you filled with dry ice, or ice ice that the fuel line circled through.

[BKBridges]

Hot fuel is lost HP... I think the rule of thumb is 1hp lost for every DegF hotter the fuel is from "baseline". Last time I baselined my car the dyno room was 118deg F and my fuel temp was about 65 deg hotter in the rails...HP was down a bit from the previous session when things were a bit cooler. Im not too concerned since its EFI adn it cant vapor lock the way its set up (and Ive got decent power "hot". Ive seen fuel tank temps rise 10 deg in an hour on the chassis dyno (EFI car with return line). Some guys go as far as to use the A/C system to cool the fuel rails with evap cores wrapped around the rails. The guy in AZ that did it said "why not? cant drive without the A/C on here anyhow" He was very consistent at the track. Just another variable!
Bruce

[Stich496]

fuel is 183* in the rail.. !!!!!!!!!!!!!!!!!!!
must not have a return line all the way to the engine

[TC]

What you want to use and what I'll be using on my '71 Camaro will be Earl's Push Lock Hose(Pro-lite 350, Super Stock, etc..)....It is what a lot of my Racer buddies are using........

Features

Quality Synthetic Rubber Hose
Maximum Pressure Rating of 250 PSI
Interior Braided Fabric Sheath
For OE Applications
For Professional Racers
Continuous Service
Suitable For Fuel/Oil/Water

http://www.holley.com/780008ERL.asp

It is also NHRA legal....

[BKBridges]

fuel is 183* in the rail.. !!!!!!!!!!!!!!!!!!!
must not have a return line all the way to the engine

The motor was getting kinda hot too...EFi has its issues..At WOT the return flow is pretty low. A big bowl of fuel in the carb can get warm but the surface area of the EFI rail contacting the smaller volume of fuel heats up the fuel a lot more. In my tests we found the rails were the main source of fuel heating (not the pump or delivery line routing)
Bruce

[BKBridges]

What you want to use and what I'll be using on my '71 Camaro will be Earl's Push Lock Hose(Pro-lite 350, Super Stock, etc..)....It is what a lot of my Racer buddies are using........



http://www.holley.com/780008ERL.asp

It is also NHRA legal....

I dont think NHRA will let you run alcohol with Pro-lite if that matters. For a race car I run mandrel bent stainless. Its not very hard to do and it builds character.
Bruce

[oj]

I'm not exactly sure, but for some reason i'm think gasoline boils somewhere in the 160ish degree zone.

[TC]

The motor was getting kinda hot too...EFi has its issues..At WOT the return flow is pretty low. A big bowl of fuel in the carb can get warm but the surface area of the EFI rail contacting the smaller volume of fuel heats up the fuel a lot more. In my tests we found the rails were the main source of fuel heating (not the pump or delivery line routing)
Bruce

How about drilling ports through the length of the injector rail and pump Compressed CO2 through them to cool the fuel/fuel rail............

[BKBridges]

Gasoline, its amazing they let us fill our tanks with it without protective gear.. .
It vaporizes at somewhere around 250? But with EFI, 40- 60psi fuel pressure extends the boilng point dramatically. The gas pretty near reaches the temp of the intake manifold due to the fuel rail heat transfer (with return) on a street/heavy traffic driven vehicle. No vapor lock but some lost power. At least theres no exhaust crossover under the intake! Those things really get cooking... Mercedes as well as Ford and a few others are now running active fuel coolers and all makes have been in-tank regulation (no return) for a decade or two...
BKB