Fuel Line Hard or Flex Line.

[TC]

5/8th" line for a sbc a little overkill, ya think

5/8's is basically -10, and I plan on running my Nitrous system off the same regulator as the carb, so plenty of fuel supply is needed.......Remember I'm using a A1000 pump with a 4 port return style regulator.....

[BKBridges]

I thought the same thing until I tried to run 5/8 hard line under my '71 camaro, with all the cross bracing it has now, it is almost impossible and I would end up with a bunch of short runs being connected by soft line. That is why I'm interested in the Push Lock stuff, it will be a lot easier to run and I won't have a bunch of connections in the middle of the line........

Anything ove 1/2" is a major PIA in stainless! Just getting the flares to seal can be a real job. I go with dual stainless 3/8" lines for the "big feed" and its a lot easier. I went to the Nylon lines for the street since its super inexpensive, its easily obtainable for repairs if necc, ultra easy to run, alchohol compatible and its more or less OEM style stuff (250psi capable, high temp nylon 12). Im not so sure Id use it on a race car though.
BKB

[DanStokes]

I'm big on SS hard line, too. That's pretty much all we used in the dyno cells and never had an issue. A little flex as needed (teflon lined SS braid) and you're done. If it runs near hot stuff you can wrap it with Kaowool (find a buddy who works on boilers and they can give you a little). It looks better if you wrap it with the foil aluminum tape that is generally used for duct work. I'm going out of my way not to say "duct tape" because folks start thinking of the sticky cloth type stuff - this is a heavy foil. It works great and can be made to look decent if you take your time.

Dan

[Stich496]

5/8th" line for a sbc a little overkill, ya think

[TC]

back to the o/p ?
I'd run solid line for as much of the run as you can..
yes it can be a p.i.t.a. to do. but it's a one time thing.. and totally worth it..
I ran teflon lined s/s rubber line once, never again . way to costly, and no real gain over hard line thats 1/12th the cost

I thought the same thing until I tried to run 5/8 hard line under my '71 camaro, with all the cross bracing it has now, it is almost impossible and I would end up with a bunch of short runs being connected by soft line. That is why I'm interested in the Push Lock stuff, it will be a lot easier to run and I won't have a bunch of connections in the middle of the line........

[Stich496]

back to the o/p ?
I'd run solid line for as much of the run as you can..
yes it can be a p.i.t.a. to do. but it's a one time thing.. and totally worth it..
I ran teflon lined s/s rubber line once, never again . way to costly, and no real gain over hard line thats 1/12th the cost

[SpiderGearsMan]

doesn't seem to help them run much better lol

[TC]

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

Mercedes has been running fuel coolers since the 70's, they would plumb them into the low pressure side of the A/C system. Here's an example of one from the 90's the one's from the 70's are much bigger......

[Barry Donovan]

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?

that is very interesting.

I did not like block pumps either..that was one of the weird things. there is others, but maine related.
the rubbers used to break random...any moment. and then there is the oil pan flooding gas soak that can sneak up on a tight engine...when it is only a leak.
at the block the line is a sucker, in a vacuum, at the tank the line is a pressure, not a vacuum but for a short gravity fed distance....

I am on a little engine.. going for 25 years. pump at tank, just outside...to the carb.
changed its first pump at 22 or so...been more than 2 years, and all else is still original.

I did find "gumout" as a spray needs to be used more for this setup...the pressure in a longer distance must be the reality.. and that is by no means a complaint.

I am going to mimick the whole setup when I get back into other older engines.

the mention of pressure keeping cool is quite bizarre, the volume is the cool, the mystery knows the distance....low pressure can keep cool too if pump is pressuring from far away..

even my little car is something near ten feet.

[BKBridges]

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

That would work. You could also run NOS through the rail cooler for the track (street?), getting an expansion boost in the nos due to the heat transfer and reducing thermal shock to the valves as well as cooling for the fuel...mount the nozzle under the injector (I think someone makes a kit to do that)...
hmm
Bruce

[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

[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............

[oj]

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

[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

[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