Vacuum and Fuel Hoses

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Zeke
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Joined: Fri Jan 18, 2002 3:01 am

Vacuum and Fuel Hoses

Post by Zeke » Thu Feb 07, 2002 12:20 pm

Yes, that is right about the fuel hose. Porsche also changed the original clamps on the individual injector hoses to to swedged fittings.

tome8689
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Joined: Fri Feb 22, 2002 3:01 am

Vacuum and Fuel Hoses

Post by tome8689 » Sun Feb 24, 2002 11:42 am

I'm restoring a 73 2.0 and want to replace all the fuel lines and vacuum lines.Need advice on what to get and where to get it.Thanks

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Bleyseng
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Vacuum and Fuel Hoses

Post by Bleyseng » Sun Feb 24, 2002 3:02 pm

I use only the high pressure FI fuel line hose from Porsche. It's rated for the FI system and the high heat inside the engine compartment. Don't use the VW stuff or rubber hose.
For the vaccum hose get it from http://PelicanParts.com
Look in their online catalog in the 914 section for it. I can't remember if they have a hose kit or not. There is also a hose guide in their site done by Dave Darling to help figure out where they all go.
If you are replacing stuff get all the pieces including the injectors seals. I also like the fuel line hose clamps from Porsche the best. They clamp the hose 360' without pinching it like the cheapo clamps do.
Geoff

------------------
76 914 2.0L

ray greenwood
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Vacuum and Fuel Hoses

Post by ray greenwood » Mon Feb 25, 2002 4:27 pm

VW/Audi Cotton braid hose is no different than Porsche. Same OEM, same part #'s, same materials, same sizes. Just don't use standard rubber hose from american cars with carbs, or fuel lines that are not printed on the cotton braid "fuel injection". Ray

oc92
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Vacuum and Fuel Hoses

Post by oc92 » Tue Feb 26, 2002 12:57 am

the reason not to get u.s. rubber type is that 1), it is s.a.e. not metric and 2), unless you get specific fuel injection type (twice the price), your pressure rating is too low.
side note- i did test new vw line with air pressure and it held well with no VISIBLE stress to 40+lbs. the clamp let go before the hose did... nice to know

ray greenwood
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Vacuum and Fuel Hoses

Post by ray greenwood » Tue Feb 26, 2002 12:41 pm

There is also a very good reason NOT to get any line without the cotton braid. With the combination of fuel under pressure inside (which opens the pore structure on the outside) and attack from heat and oil from the outside, non jacketed fuel line breaks down under the hood of an air-cooled car at avery high rate. Typically replacement is every year. Ray

thinman
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Vacuum and Fuel Hoses

Post by thinman » Wed Feb 27, 2002 3:47 pm

Is there any reason why no one seems to use copper tubing for fuel lines on the engine top. There are all kinds of flair or compression fittings avail, and 3/8" OD tube is almost exactly 8mm ID. Rubber hose can't insulate the gasoline from heat all that much. The copper tube is tough, and can sustain more pressure than the hose. Except for the connection between the chassis and engine, vibration shouldn't be a factor. And the brass fittings aren't likely to leak. What am I missing?

ray greenwood
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Vacuum and Fuel Hoses

Post by ray greenwood » Wed Feb 27, 2002 4:43 pm

No real problem, except that it will be difficult to attach to stock injectors, cold start valves and pressure regulator. I would use steel instead of copper...preferably stainless...because copper grows a lot more with heat....but there really isn't enough pressure to warrant the hassle. The cotton braid of stock lines also keeps the fuel line from losing integrity and making minute changes in fuel pressure by bulging. Ray

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bowlsby
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Vacuum and Fuel Hoses

Post by bowlsby » Wed Feb 27, 2002 10:12 pm

I agree with most of the above and have this to add:

Early in the 914's life, there were problems of engine fires (specifically related to the fuel lines which run beneath the battery) caused by rain-washed battery acid dripping down and deteriorating the plastic fuel lines.

Porsche issued a safety recall to the early cars and I am 99% sure that as part of the repairs in the safety recall, Porsche changed the vacuum hoses to the non-cloth type because the cloth type apparently caught fire easier.

Can anyone confirm?

On the fuel lines, I'd stay away from copper lines because they are very soft and their coefficient of expnsion is high. The pressure rating (with a large safety factor) would need to be verified.

Summit racing has aluminum tubing and stainless steel lines available. I tried the stainless lines (not from summit) and had mucho trouble getting them to form any radius, much less the tight radius needed at the firewall. The plastic lines in the tunnel generally are not a problem as they are protected from heat, but the other engine bay lines often fail and get brittle. I have used heavy wall aluminum tubing fuel lines for 3 years now in the engine bay, without any problems.

[This message has been edited by bowlsby (edited 02-27-2002).]

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