Forming Fuel Line

For those that have 944's and in particular the Pre 85.5's the fuel line from the tank to the pump is in the shape of an elongated S. Or a better description would be a strait piece with two bends on the ends that are about 270 deg bends. The fuel line is 1/2" id. Porsche actually sells this piece (it has a part number on it) But it is $20 plus shipping and I have several feet of 1/2 inch fuel line left over from a previous project.

I was actually thinking of using some copper tubing and inserting it into the line and then bending it. Yes this would put a bit of a restriction into the line but I don't think it would be enough to hurt things. The other option is to just purchased a couple of 90 deg fittings and piece together something. However this would require a bunch of hose clamps and I would probably end up spending more than the $20 for the part. The last option is the bend up a replacement from soft steel or copper line flair the ends and then add two small bit soft hose to connect it to the tank and the pump. I have the bending tools and the flaring kit so this is easy however I am not sure I want a sold line running form the tank to the pump. The pump has quite a significant isolation system of rubber mounts on it and thus I suspect it vibrates quire a bit. I am not sure vibrating a steel line that much is a good thing.

SO. After explaining all this my question is there a way to bend tight radius's in to fuel line and have it keep the bend while not collapsing the line? I could make a jig out of screws/wood to retain the line and then heat it / bake it. I have several 1800 deg thermal plastic hot air welding guns that I can make a nice little oven by building a box out of pieces of foil faced polyisocyanurate insulation and then use the hot air welders to heat the contents of the box. Anyone else have any ideas?

Use a fuel line bender. A couple bucks at HF. Also use fuel line, not copper. "They say" that copper can get hard and crack and cracks in fuel line are bad. Not that thousands haven't done that over the decades, just sayin'.

I think I would spend the sawbuck. Or go with stainless braided, but the ends and the line would be way over the sawbuck.

It already does not sound like it is worth the trouble to fab one when the correct part is $20 plus shipping. Sorry.

I was gonna say, there's an actual Porsche part available for $20? That's amazing.

Is your left-over line aluminum? I did alu fuel lines for my project, 1/2" ID supply 3/8" return, and I had the same concerns, even got benders which I found useless. I actually found the aluminum tubing to be very easy to bend by hand to a pretty darn tight radius (like 2-3"), just going a bit at a time.

If you're really worried, or need an even tighter radius, one way I know is to fill it with water, freeze and then bend with ice inside.

But I agree that if you can get something that's not a screw or trivial to substitute with something from Home Depot for 50 cents, for 20 bucks from Porsche, just do that.

I have some 1/2 inch low pressure fuel line (rubber) I also have some 1/2" steel line. Ya I will probably just order the part but it is a week to get it. It is just not in my nature to pay $20 for an 8 inch long piece of fuel line. Ok Yes I know it is a Porsche but still.

I am just finishing up replacement of the gas tank and I am anxious to drive the car again. It has been up on jack stands since the end of October and believe it or not it is a much better winter car than my mustang. All things being equal (4 snow tires on each car) The Porsche is truly a superior winter car.

BigD wrote: If you're really worried, or need an even tighter radius, one way I know is to fill it with water, freeze and then bend with ice inside.

That is brilliant. I have used sand in the past. but that sounds like a much better option as you don't get any dust debris in the line. With tight bends in small diameter line things can get stuck in the line. With Ice just wash it out and go! Brilliant!!!!

BigD wrote: If you're really worried, or need an even tighter radius, one way I know is to fill it with water, freeze and then bend with ice inside.

+1

It may work even better if you add soap to the water. I got that idea from watching this video on trumpet building. (Some pretty cool hand fabrication of metal bits. It is worth watching even though it is not fuel-line stuff. The trick with the soap starts at 3:20)

I still haven't tried the soap/ice trick, but I'll be making fuel lines for the datsun soon.....

Wouldn't adding soap decrease the freezing point of the water? It may never freeze. Regardless, that is a brilliant idea. Just wish I had a bigger freezer to bend suspension a-arm metal.

cheap alternative to a mandrel bender?

Teh E36 M3 wrote: Wouldn't adding soap decrease the freezing point of the water? It may never freeze. Regardless, that is a brilliant idea. Just wish I had a bigger freezer to bend suspension a-arm metal.

It probably does decrease the freezing point. If you listen to the narrator, those trumpet bends were done at -49 Celsius. It should not be a problem, though.....Dry ice is readily available, and is -56.4 Celsius.

noddaz wrote: It already does not sound like it is worth the trouble to fab one when the correct part is $20 plus shipping. Sorry.

I'm cheap as all hell, and that sounds worth it to me, too.

+1 on just buying the right part. Its amazing how bad the quality of aftermarket rubber line is compared to factory stuff. $20 is not that much when it comes to being safe.