MyBlackCar

Has anyone attempted a custom stainless steel hard line to replace the soft fuel line portion going over the exhaust to the fuel rail? I did a search and only found stainless steel braided modifications.

My idea would be to route it towards the back and run parallel to the fuel rail. It would attach to the main hard line and fuel rail via soft injection line protected by fire sleeves.

Legoland951

As your engine vibrate and rotate from accel and decel, your hard line will break eventually causing a fire which is common to the 944 series. This is why they used braided or rubber line.

marky522

you Could do a hard line with a flex line at the rear out of the way,just for a spot to flex. just watch that flex line becasue due to the fact its shorter it would probably wear out faster. But you could use that stainless flex and be fine.

Mark

Darwantae951

Rubber is a better insulator than metal...metal lines so close to the headers doesn't sound good to me.

-Darwin

kevincnc

It sounds to me like you just want to run hard lines to the back of the fuel rail, then the soft lines from there to the existing hard lines. If that's the plan, it sounds like a nice, safe, clean way to go if done properly. If you hook into the FPD and FPR with a rigid pipe that goes to the back, they would have to be mounted differently which could be a challenge. Some kind of good vibration mount maybe. Sounds like a good project.

MyBlackCar

Yes. That is spot on. I guess more research is in order.

gstein

I don't see much sense in this modification. Engineers know more than you....trust them.

ekeeton

While you're in there mount a fire extinguisher.

marky522

So there isnt a possibilty that in the last 20 years methods have changed??? What he wants to do is basically the way that the new Porsches are now, only difference would be that the body lines are plastic now. But same idea, solid lines on the engine, fixed lines on the body, and a flex piece inbetween.

Mark

F18Rep

I think the trick will be mating the new hardline to the rail, that fitting is tough to find. Earls makes a metric to AN adapter ( I think they call it Saginaw) but the metric part doesn't include the globe-seal. Find a good adapter/fitting and the rest is just everyday plumbing. ...Bruce

Legoland951

He is talking about a late car since the fuel line goes over the headers. The late car configuration is hard steel line on the body and hard steel line on the fuel rails with rubber inbetween and NOT what you are thinking with lines coming to the rear of the rail. If you get rid of the rubber, every time you accelerate and decelerate the engine will torque one way or another wearing out the steel lines leaking gas right down to the exhaust causing an instant fire. There is a MANDATORY DOT safety recall on the 944 series cars fuel line since the cars burn down to the ground with the rubber. This is why people only make flexible braided steel lines to replace the rubber ones. If you replace the rubber lines over the exhaust as he mentioned in the original post, it will be hard line ONLY in the whole system from the body to the fuel rail and I hope you have a good lawyer if you are recommending him to do this because he may be coming for you when his car burn down to the ground. I have seen this happen in front of me twice in person. Ask Porsche O Phile why he got rid of all 3 of his 944s/951s to get a 911.

kevincnc

This is what he said: "My idea would be to route it towards the back and run parallel to the fuel rail. It would attach to the main hard line and fuel rail via soft injection line protected by fire sleeves."

Legoland951

Thanks for pointing out what didn't register in my brain from the original post. The early rail is already built like that so the end result would be like putting an early rail on a late car with late spec FPR and damper if its different from the early rail. However, the hose still has to get into the wheel well somehow and the only way is over the exhaust headers unless you do some pretty extensive modifications to the body hard line so I don't see much of a benefit over heat sleeved stainless braided lines at the factory location.

gstein

I am curious what sparked this idea of hard lines in the first place. It is understandable that some Porsches use hard lines because they use smooth-running boxer style motors, but our 944's are infamous for engine vibration. The engineers were pretty successful with the twin balance shafts in mitigating the effects of such a high displacement I-4, but there still remains a decent amount of vibration. It just seems risky fooling around with a serious issue like fuel when I recollect all of the toasted 944's I've seen.

Best Regards,
Benjamin Goldstein

F18Rep

Try this... pick a nice hot day, go for a short drive, open the hood and and get a good bare-handed grip on those OEM rubber lines. Now hold on and count to 30.

One of the sad realities is that many such things as this are decided by bean-counters, not engineers.