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914World.com _ 914World Garage _ I'm going aluminum

Posted by: Headrage Feb 16 2005, 06:03 PM

I've been researching different alternatives for replacing my fuel lines and, after talking to a bunch of motorheads and car builders around town I've just about decided to go with 3/8th inch aluminum. Input from you guys would be appreciated before I actually do anything.

Posted by: mattillac Feb 16 2005, 06:21 PM

how about stainless steel? why did everyone recommend aluminum?

Posted by: Headrage Feb 16 2005, 06:29 PM

Seemed to be a general concensus that it has proven reliable on the track as well as ease of installation.

Posted by: mattillac Feb 16 2005, 06:36 PM

i don't know why, buy i don't think aluminum would be all that great. aluminum doesn't really bend all that well, right?

Posted by: Headrage Feb 16 2005, 06:40 PM

Seems to work http://www.914world.com/bbs2/index.php?act=ST&f=2&t=8830&hl=aluminum+fuel+lines okay.

Posted by: john rogers Feb 16 2005, 06:41 PM

The aluminum will get brittle from the chemicals in our wonderful modern gasoline and vibration will probably cause cracks. I used 3/8 inch stainless brake line from NAPA when I did ours and it works fine.

Posted by: mattillac Feb 16 2005, 06:47 PM

stainless would be stronger. it would be pretty easy to accidentaly crush the aluminum lines when you're working on the car or something.

Posted by: bd1308 Feb 16 2005, 06:48 PM

QUOTE (john rogers @ Feb 16 2005, 06:41 PM)
The aluminum will get brittle from the chemicals in our wonderful modern gasoline and vibration will probably cause cracks. I used 3/8 inch stainless brake line from NAPA when I did ours and it works fine.

aluminum age hardens and work hardens......both are bad for lines you dont want to crack....use stainess

Posted by: Headrage Feb 16 2005, 06:51 PM

One of the guys I talked to has a '68 Chevy 4x4 that he restored in '82 and drives it out in the desert all the time. Says he has never had a problem with them.

Posted by: BigD9146gt Feb 16 2005, 06:57 PM

Aluminum actually bends really easy... but it all depends on what alloy you use. What aluminum tubing did everyone you talked to suggest? What supplier?

Everything work hardens. Like all materials, the more you cold work it the more likely its giong to tear. A one-time bend with some aluminum tubing isn't going to be a problem (again, depending on the alloy).

Posted by: Headrage Feb 16 2005, 07:02 PM

These were mentioned http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=2704&prmenbr=361 and http://allstarperformance.carshopinc.com/product_info.php/products_id/4516/40180. Oh yeah, 5052 is recommended.

Posted by: Cap'n Krusty Feb 16 2005, 07:05 PM

Unless it's properly secured and in well fitting brackets and bushings, I wouldn't use aluminum. We see fatigue related failures in aluminum tubing all the time. I see NO benefit over steel or SS, but then I stick to the stock plastic in both my own cars and those of customers. The Cap'n

Posted by: scotty b Feb 16 2005, 07:07 PM

I would not go with aluminum, yes it bends easily but it also cracks easily. Think about how much twisting and flexing your car does going down the road. Unless you do some seriously hard attaching I don't think it is a good idea. My oldest car is a 51 Lincoln,it still has the original steel lines and they do just fine. I personally don't see any reason not to go with steel but I do see many reasons not to use aluminum. Get a metallurgy book and read up on aluminum and you will see why not to.

Posted by: Mueller Feb 16 2005, 07:07 PM

Summit Racing sells the Russell aluminum fuel lines and appropriate connections....just use some common sense, make sure you use rubber insulated clamps, use rubber lines in-between any two mounting points that vibrate (from chassis to motor)...

if the lines flexed while mounted in the center console to start to work harden, you have bigger problems to worry about

Oh yea, I'd pony up the extra money and get a 25' roll of both colors, red and blue, use one for (red) for the high pressure or fuel going to the motor and use the blue for the return line.

The Russell line is rated for 250psi

Let me know if you go this route, I'll split a roll of each color with you.....

Posted by: Britain Smith Feb 16 2005, 07:12 PM

My 912 had an aluminum line stock. I still have it sitting on a shelf somewhere.

Hey Mueller, post a link or something. I wouldn't mind taking a look.

-Britain

Posted by: BigD9146gt Feb 16 2005, 07:31 PM

I should keep my mouth shut, and I'm not trying to be dick, but you guys who are saying "no" need to do more research. If you wouldn't want to use aluminum from a preference point, thats cool, no arguement here.

But how much flex does the 914 encounter along the center tunnel? And "A lot" is a pointless answer. Lets work this out... Over the lenth of 5 ft, at the center tunnel, the chassis flexes, but how much change in direction do you get? Even in angular rotation, maybe 5 degrees...

It seems like a lot more, but think about where your sitting and what your looking at when all of this occurs. Your sitting on the side, looking at the outter corners of the car raising and lowering with the only reference being the ground that your traveling over. Where we sit is not a reference point for what goes on in the tunnels.

"Aluminum cracks easily": which alloy are you talking about? 3000 series is very flexable, thats what a lot of people use as body panel forming. 5000 series is used widely on aircraft, and i use it on the oil tanks because i can bend it and it doesn;t crack at the seam like the 6000 series does.

Its all about application, and if everyone did just a little bit of homework, life would be soo much easier. But all it takes is one person to say "NO WAY!", "YOU CAN'T!", then everyone that reads it takes it for the truth.

Posted by: Mueller Feb 16 2005, 07:32 PM

QUOTE (Britain Smith @ Feb 16 2005, 06:12 PM)
My 912 had an aluminum line stock. I still have it sitting on a shelf somewhere.

Hey Mueller, post a link or something. I wouldn't mind taking a look.

-Britain

here you go:

http://www.russellperformance.com/auto/fuel/fuel_manage-adapt.shtml

Posted by: Mueller Feb 16 2005, 07:35 PM

QUOTE
I should keep my mouth shut, and I'm not trying to be dick, but you guys who are saying "no" need to do more research

I always respect the Cap'ns advice (don't follow it all the time, LOL)...a few (2) of the other guys are just quoting stuff and have not been working on cars or anything long enough to give out "known" knowledge

Posted by: scotty b Feb 16 2005, 07:45 PM

I simply stated my opinion on the subject. I HAVE been working on cars for a living for 12 years and think I have enough knowledge to state MY OPINION. I'm not going to get in a pissing contest over this and will admit I'm not a metallurgist but I do know how aluminum works and I do know that the cars flex and I do know that the stress points on the line will be where they ENTER and EXIT the tunnel not in the tunnel. Do as you please, I read the beginning and understood that opinions were wanted so I gave my OPINION.

Posted by: Mueller Feb 16 2005, 07:54 PM

QUOTE (scotty b @ Feb 16 2005, 06:45 PM)
I simply stated my opinion on the subject. I HAVE been working on cars for a living for 12 years and think I have enough knowledge to state MY OPINION. I'm not going to get in a pissing contest over this and will admit I'm not a metallurgist but I do know how aluminum works and I do know that the cars flex and I do know that the stress points on the line will be where they ENTER and EXIT the tunnel not in the tunnel. Do as you please, I read the beginning and understood that opinions were wanted so I gave my OPINION.

i think he was talking about the other 2 guys

i found another "scott" for you

Posted by: anthony Feb 16 2005, 08:04 PM

QUOTE (Headrage @ Feb 16 2005, 05:03 PM)
I've been researching different alternatives for replacing my fuel lines...snip

So what's the problem with the stock lines? Are they broken/leaky?

Posted by: scotty b Feb 16 2005, 08:07 PM

Thanks Mike I saw him. He obviously is one of us since he was always bitching about needing more power! I'm givin her all I've got but she's just a 1.7 Cap'n1

Posted by: Headrage Feb 16 2005, 08:10 PM

QUOTE (Mueller @ Feb 16 2005, 05:07 PM)
Let me know if you go this route, I'll split a roll of each color with you.....

Deal. Russell says you can get it at any Aotozone. You want me to pick it or or do you want to do it. And don't worry guys, the only contact to the lines will be grommets and insulated clamps.

Posted by: Headrage Feb 16 2005, 08:12 PM

QUOTE (anthony @ Feb 16 2005, 06:04 PM)
So what's the problem with the stock lines? Are they broken/leaky?

PO cut them in all the wrong places. Oh yeah, it's also one of those "Since I'm in there" things.

Posted by: scott thacher Feb 16 2005, 10:20 PM

real tough ( sacastic ) job just did my supply line ( front pumper ) took all of an hour, including pulling and replacing the tank. i used 2 pieces of steel brake line and a coupling where it comes in to the engine bay. i bent it by hand, and will now have a 1 foot piece of high pressure line going to the engine

Posted by: d914 Feb 16 2005, 10:28 PM

just did mine with -6 fittings and pushlock/ or twist lock (source??) hose and fittings. Easy to do, fairly tough, easier than ss braided lines. Not the cheapest way but easy to work on later.

Posted by: campbellcj Feb 16 2005, 10:35 PM

I have the Russell 3/8" aluminum tubing thru the tunnel, mated to AN-6 braided on both ends of the tunnel. The tubing is flexible, not brittle and thus far no issues. (IIRC it is explicitly spec'd for fuel applications.) My car has a welded cage and fire system so may not be an apples and oranges comparison. Oftentimes what "makes sense" for a street car vs a race/autox/offroad car are completely different things.

Posted by: Lou W Feb 16 2005, 10:44 PM

QUOTE
anthony Posted on Feb 16 2005, 06:04 PM
QUOTE (Headrage @ Feb 16 2005, 05:03 PM)
I've been researching different alternatives for replacing my fuel lines...snip

So what's the problem with the stock lines? Are they broken/leaky?

When I removed my engine a couple of weeks ago, I bent the stock plastic fuel line about 90 degrees and it snapped in half. I will definitely be replacing mine.