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HybridZ

Plumbing fuel and brakes on a budget


JMortensen

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Jon,

I used a bunch of those brass fittings the MrFancyPants is talking about for plumbing the fuel system on my Z. As he says they are very hard to push into the correct size hose and will not pull loose. It's recommended that you lube them with a small amount of oil when inserting them. The high pressure hose is not much more expensive than conventional rubber fuel line and if you plan to swap in an LS1 later it's worth it to do it right the first time.

 

I used a combination of 3/8" stainless hard line I found at NAPA that is double flaired and the high pressure rubber with those brass fittings. The hard line was a bit of a pain to work with but once in place can be ignored. I think I spent a little over $100.00 for all the parts of my fuel line but thats because I bought extra parts and did the fuelatank end twice.

This is interesting. How to you connect the locking hose to the hard line? Does that push on style hose work with regular double flared hard line? I thought you needed that gnarly triple barb end to grab onto that style of rubber hose.

 

As far as the hard line, flared stainless would be the poop. I was thinking of using aluminum and was unsure about the strength of it. If stainless hard line is available inexpensively that's definitely what I'll use.

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Man. You have to hate it when someone shows you a better way after you already have parts in hand.

 

Looks like Summit sells an aluminum version for only $3 a piece.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2D220756&N=700+4294924496+4294839052+4294849583+4294906726+4294906724+115&autoview=sku

 

Couldn't find a tube to hose barb adaptor on Jegs or Summit. Doesn't mean they don't exist.

 

One tip on the stainless hard line. I read one article that said to use a hack saw to cut stainless hard line rather than a tubing cutter. Said the tubing cutter will work harden the stainless making it impossible to flare.

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Jon,

Here is an old picture of how I routed the hardline I used. At the very top of the picture you'll see one end with a brass double flare to AN adapter and then a brass AN fitting. The adapters I got with the line from the NAPA store and the AN fitting from the same local hydrualic shop where I got the high pressure push in fittings.

 

fuellineroute.jpg

 

Hope this helps, if you want better pictures let me know and I'll see what I can do. I've redone part of this system since the picture was taken but the design is the same. I got rid of the kink thats visible in this picture and the tank has been replaced with one from a 2001 Camaro.

 

POP,

I wish I'd known that about the tubing cutters hardening the stainless line. I tried to cut and reflare a new section of the fuel line and couldn't do it. I thought it was my cheap HF flare tool but maybe it wasn't. I've had no problem with the smaller 1/16" brake line but the 3/8" was impossible to flare.

 

Wheelman

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One tip on the stainless hard line. I read one article that said to use a hack saw to cut stainless hard line rather than a tubing cutter. Said the tubing cutter will work harden the stainless making it impossible to flare.

 

That was one of the things that I learned in a tube bending class that I was in recently. Jon here is the tubing that I used for my fuel line http://www.mcmaster.com (it will not allow a direct link so search for part # 5177K46) it is rated to 1008 PSI @ 100 deg. F and was very easy to bend and fit using a cheapy tubing bender.

 

Dragonfly

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Since I can get refrigeration copper (soft drawn 50ft length any size OD not home depot CRAP copper ,) for very cheep. I would use copper benefits are easy to bend, easy to cut, easy to flare and will never rust or rot out. and compared to SS it is cheaper even if you had to pay full price for the rolls of copper and fittings. Best thing is it can handle any psi and heat level on any car. this of course is My opinion.

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Since I can get refrigeration copper (soft drawn 50ft length any size OD not home depot CRAP copper ,) for very cheep. I would use copper benefits are easy to bend, easy to cut, easy to flare and will never rust or rot out. and compared to SS it is cheaper even if you had to pay full price for the rolls of copper and fittings. Best thing is it can handle any psi and heat level on any car. this of course is My opinion.

 

I can not see a problem with using copper tubing for fuel line (although you may get some frunny looks from people who see it) but everything I have ever read says to never under any circumstances use copper tubing for brake systems.

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Since I can get refrigeration copper (soft drawn 50ft length any size OD not home depot CRAP copper ,) for very cheep. I would use copper benefits are easy to bend, easy to cut, easy to flare and will never rust or rot out. and compared to SS it is cheaper even if you had to pay full price for the rolls of copper and fittings. Best thing is it can handle any psi and heat level on any car. this of course is My opinion.

 

 

 

I understand that you intend to use the copper line for fuel... but when you say it can withstand ANY pressures on a car... I wonder what it is rated for... throw a number out there... I doubt it is suitable for brakes...

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I did my fuel lines using aluminum tubing with a/s tube nuts and sleeves, it was about the cheapest way possible, not much rubber to worry with and the aluminum tubing is flexible enough that it can hang from my fender to the fuel rail without flopping enough to be a problem, the JIC stuff is ok, same 37 degree taper as the a/n but it's much heavier steel, cost a fractiona and comes in brass finnish

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The allowable internal pressure for copper tube is based on the formula used in the ASME Code for Pressure Piping (ASME B31):

 

formula1.gif

 

Because of copper's superior corrosion resistance, the B31 Code permits C to equal O, and the formula becomes:

 

formula2.gif

 

The value of S in the formula is the maximum allowable stress (ASME B31) for continuous long-term service of the tube material. It is only a small fraction of copper's ultimate tensile strength or of the burst strength of copper tube and has been confirmed to be safe by years of service experience and testing. The allowable stress value depends on the service temperature and on the temper of the tube, drawn or annealed

.26

  • drawn temper - also called "hard" or "rigid"
  • annealed temper - also called "soft" or "flexible

Rated Internal Working Pressure for Copper Tube: ACR*

(Air Conditioning and Refrigeration Field Service)

 

Part 1: 1/8 - 1-5/8 inches Nominal

or

standard

size,

in inchesCoils, Annealed S=

6000 psi

100FS=

5100 psi

150FS=

4900 psi

200FS=

4800 psi

250FS=

4700 psi

300FS=

4000 psi

350FS=

3000 psi

400F1/

Nominal

or

standard

size,

in inchesAnnealedS=

6000 psi

100FS=

5100 psi

150FS=

4900 psi

200FS=

4800 psi

250FS=

4700 psi

300FS=

4000 psi

350FS=

3000 psi

400F3

Nominal

or

standard

size,

in inchesDrawnS=

10,300 psi

100FS=

10,300 psi

150FS=

10,300 psi

200FS=

10,300 psi

250FS=

10,000 psi

300FS=

9,700 psi

350FS=

9,400 psi

400F3

 

 

 

*Based on maximum allowable stress in tension (psi) for the indicated temperatures (°F).

**When brazing or welding is used to join drawn tube, the corresponding annealed rating must be used.

just some numbers to crunch, however I was only refering to fuel line pressure but a good read is http://www.markwilliams.com/braketech.aspx

As the fluid becomes contaminated with moisture, its boiling temperature drops. Only one percent moisture can lower the boiling point of some DOT 3 fluids down to 369° F. Two percent water can push the boiling point down to 320° F, and three percent can drag it all the way down to 293° F - which is getting dangerously close to the minimum DOT requirements.

3/8.035-SS stainless steel tubing

O.D.: 3/8

Wall Thickness: 0.035

I.D.: 0.305

Max Working Pressure (6:1 SF): 2333 psi100F

1/2.049-SS stainless steel tubing

O.D.: 1/2

Wall Thickness: 0.049

I.D.: 0.402

Max Working Pressure (6:1 SF): 2450 psi100F

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To quote http://www.markwilliams.com/braketech.aspx

"Mounting the master cylinder to a frame rail or roll bar is recommended to ensure a solid mount. With the correct master cylinder in place, the pedal ratio must be great enough to produce 1200 psi system pressure under severe braking conditions. A pedal ratio versus line pressure calculator is available below. We recommend using a pressure Gage connected to the system to verify the maximum available pressure before running the car. If the desired pressure can not be easily attained the pedal ratio must be increased until the minimum pressure of 1000 psi is easily reached."

 

However, like I said I was referring to the fuel line pressures when I said any car pressure and any temp..sorry for the confusion (still 1600+ is better than 1200 psi under sever conditions). which is what that site says but I do not want to pretend to know what the actual psi is since I do not.

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