I see a few companies are selling new stainless steel fuel lines, new fuel lines on our 50 years old cars is generally not a bad idea, but how about if they appear to be in good condition? The feed line on our car is about 10mm OD with a 1mm wall. While we are in there should they be replaced for good measure.

Thanks

The plastic fuel lines grow brittle with age. When they rupture, you get an engine fire.

Been there, done that. Don't want to have another engine fire.

Replace them with the Tangerine racing kit. It fits well and works great.

Clay

Bit of two sides of the fence for this question, some like Capt Crusty (rip) and myself believe if the lines are in good condition, in a good condition car, then they are fine to leave alone.
But in your case extensive strucual metal repairs and the lines have been removed or molested I agree that replacement is prudent.

From what I can tell everything appears ok, but for a hundred or so dollars why risk a chance for a fuel leak. I salvaged a short piece from the engine compartment and seems fine, but who knows what has happened inside the tunnel or at the ends where the lines enter/leave the tunnel. By nature I am a risk taker, but not with pressurized fuel.

The 75-76 cars had a completely different material and are less prone to failure. With that being said my 75 lines were good through tunnel BUT brittle from the firewall turn to engine shelf. The fuel pressure is 28-30 lbs and you are correct, there is a chance of failure.

If you moved your pump to the front then yes one line has 30psi pressure. If your pump is still in the engine bay then the the tank lines front to rear are not pressurized. FI systems are only pressurized from the pump to the regulator, the feed and return lines are not pressurized.

Other points:
Only use FI hose clamps.
Use only FI rated hose, I used to say you can use low pressure hose on the low pressure parts of the system and you could, but I just use FI hose throughout now.
Use proper grommets wherever tube or hose passes through drilled holes in chassis metal.

I just refreshed the whole system from tank to engine. When i pulled the lines (75) they looked fine so that was a comfort but it is cheap insurance when you are investing time already in the car. Why risk it? I considered selling the lines with how great they looked but no way i would want someone to trust their car to old lines.

It sounds simple/safe/smart, but looks like a pita job. The lines appear pre bent and how do we snake these through the tunnel?

Whose new lines are preferable? Pelican, Tangerine, 914 Rubber? car will be probably running D or L jet

I had a second pair of hands so that helped for sure. Install from the engine bay side and guide them through center tunnel. Just take your time. Took us about 10 minutes all together taking it slow.

"73 1.7 & mine are still soft & pliable.

Mine came from Tangerine.

I had same concern but, like others it was a 10 minute job without help. Once you have the orientation right they kind of navigate themselves.

I am not sure if this was the 914 or another vehicle but, I have vague recollection of tying a long string to end of original line and then attaching that to same end of new line to help guide through the grommets.

For me, the hardest part was getting the tank back in without crimping the fuel hose.

Thanks, after looking into it a little and then feedback I will order the kit from Tangerine.
I can recall years ago when an Amphicar could be had on the cheap, but what wasn't?

If you lube the stainless line so it slips through the rubber grommet at the firewall (wd40 is fine) and have a spotter in the cabin with a flashlight, it's an easy 5 minute job.

As usual, @iankarr has a nice video on the installation. It really is an easy task even if done solo. BTW, I got my SS lines from member @Rotary914


https://www.youtube.com/watch?v=IDFsZoI_W3g

Watched it last night, placed an order for the kit from Tangerine this morning. Simple

We have a few other older sporting cars in the stable, it has been on my list for years to change out all the fuel and brake lines ....

I just did this on my 1970. Had the tank re-done, new SS lines from Tangerine and all new rubber lines everywhere including engine compartment. It was time consuming but not bad. I did the tank to firewall lines by myself with a lift. It took a bit to get them through there but not terrible. You do have to take quite a bit of stuff apart. I'm a pro now at removing my seat, pedal board, steering wheel, etc. :-) My biggest issue was dealing with the plumbing from tank to pump (re-located to front by PO) to avoid kinking the hose. I put a new two port pump in. The PO had someone re-locate the 3 port and it was literally zip tied to the steering rack. Tangerine sells a proper two port pump mount. For me having seen my rubber injector hoses leak and knowing how old the car is, it was a no brainer. Cheap insurance in my opinion.

If you like your car, replace them. Cheap insurance to avoid catastrophe.

https://youtu.be/Oq8OyuQAg7k

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That is a plastic fuel Y on a 13yo Cayman that cracked due to age. That Y happens to be directly over my header on the drivers side.

I got lucky.

Imagine your plastic at 50yo...

Don't even think about this - go stainless now!

Done, a new kit from Tangerine is on the way.

Cheap insurance against an engine fire.

Thank you for the information. Now I know if I ever buy a Cayman, (Boxster I assume also) I should check for the fuel lines...

I always have a fire extinguisher on board, but the best one is the one that's never used.

Every 914 we own has a fire extinguisher in it. But I like to stack the odds in the favor of not using it.

just did mine 12 months ago for recommission.

i found the orig plastic lines were theoretically still in good condition in the tunnel but were brittle from the firewall out, including being brittle just inside the firewall and passenger compartment. if they were going to let go there would be a chance of it happening at that point as well as underneath and inside the engine compartment.

not a pleasant though having a passenger compartment full of fuel - aside from the idea of an engine compartment on fire. i could be wrong but i think the fan shroud housing on a type 4 motor is magnesium. if so this contributed to all the legends of 914s burning fiercely, esp when the fire brigade rocked up and put a water hose on them!

i made my own mild steel fuel lines. if i was in the usa and had a lhd car i would have bought one the kits available. but they don't fit a rhd converted car at the top end near the pedal cluster. anyway, it was fun to do making some lines. strangely the plastic lines, once you pull them out, keep the shape of their track through the tunnel, so you can use that to configure the bends and get them real close. from there its just a matter of adjusting adjusting adjusting until they fit nicely without fouling on anything else.

i was worried about them vibrating and making noises. but so far so good.

ps - its good to check the fuel lines after you do all this, each time you drive the car.
i have heard talk that modern flexible fuel lines can expand or shrink during the first 6 months they are on so its worth making sure that all the joins between flexible sections and steel lines are not leaking anywhere. given there was documented trouble with leaking fuel lines when the cars were new this was probably a problem back in the 70s too?

It's actually hard to get solid mag to catch on fire. I heat the cylinder bore on mag cases with a mapp torch to loosen head studs on 911 engines. No problem hitting the mag for 2 minutes with a very hot flame. It's the raw gas spraying under pressure that really fuels the fire.

@ mepstein, thats a relief to know. not that i want a real world test.

have seen what bushfires do to mag and alu wheels here as well as some engine blocks. melts em. but temps inside a bushfire are insane and don't bear thinking about.

Yes. They melt steel, cinderblock, etc.

That’s what’s so nice about the stock fuel injection. If you smell gas, something is wrong.

Photos are from my ‘70

There are tabs inside the tunnel (under the gear shift) to hold the fuel lines so they are not loose. And I added some rubber collars made from split rubber tubing in a couple of places so the metal lines do not vibrate against the tunnel floor.

@ bkrantz

yes, i locked in on those tabs.

was more concerned at the front end where i had to get lines up and over the pedal linkage axles. a bit hard to explain but with rhd conversion there are axles coming through from rhs that you run right across tunnel. rhd 911 is similar.
the lines have to rise up over those and then turn and rise again to get out through the front firewall. where i was worried about vibrations. was a bastard getting those convolutions right and it made feeding the lines down the length of the car that little bit harder. lots of walking away, quiet cig and then another go at it.

added complication in a rhd car in the under engine bay area. the handbrake lines you swap over to the rhs sill. just another cable that wants to make life complicated where you are bringing the fuel lines out of the tunnel and working along the back of the firewall. you are dealing with the rigid curved pipe penetration for the handbrake cable that is on the lhs of normal cars. imagine the whole lhs side set up mirrored and taken across.

be thankful you have lhd cars.

@ mepstein - re smelling gas. i have noticed i occasionally get a faint smell of petrol in the engine bay. but no leaks. the smell goes away after a run. i am pretty sure its a saturated charcoal cannister. thats were my nose has been leading me. seems to build up while the car is standing.

my plastic fuel lines were nearly as bad as yours in photo but not quite. the flexible ones were in better shape. probably because i put all new ones in back around 92.

here is a shot of the plastic lines after i pulled them out. what i meant about them keeping their shape through the tunnel.


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There are lot's of threads on the samba about refilling a charcoal canister. On my early car, the end is not removable so I took a 2" hole saw to it, filled it up with fish filter charcoal and duct taped over the hole. I made the hole on the bottom so you don't see the duct tape. The fish charcoal isn't supposed to be as good as the original but it works fine and is cheap. The original canister can also be taken out of service and left in fresh air for the charcoal inside to refresh. So having two canisters and switching them out every couple years is also an option.

The other thing is to make sure all the rubber hoses are good and on the fuel hoses, use the correct fuel clamps, not the worm drive ones.

@ mepstein. yep, all the fuel lines are good. and been checking them.

i've read (and looked at) that the way the cannister works on the early vw systems like the 914 set up - the cooling fan is blowing through the cannister forcing evap fumes into the aircleaner. the charcoal is in effect the valve. blower hose is on the far side of mine and the tank line and aircleaner line are on the opposite side. its an engine bay cannister mounted on the engine side of the rear trunk fire wall. the way i figure it is the car maybe needs a good long drive at freeway speed to purge the cannister? sort of goes with the way the smell seems to come and go in mine. after i have taken it out for a spin it goes away. after a week or so its back again.

i honestly could not be farked doing the gold fish tank charcoal change bs.
a good long hard drive sounds way better - doesn't it?
just got to wait for the roads to clear. its madness down here.
every kook under the sun is out on the highways right now after the huge deeply depressing 3 month covid lockdown the govt. made us endure the past winter.
roads are clogged with every aussie off on their outback discover their own country bullshit towing caravans swaying down the highway or losing control of their 4x4 they can't drive. ......this is the country that gave you mad max. not anymore.