Author Topic: Fuel pipes  (Read 3909 times)

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Fuel pipes
« on: November 24, 2004, 16:51:37 »
Can anyone tell me the specs on the hard fuel pipes, material,coating, diameter etc? How about a source for new ones and an approximate price?

Mikey

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Re: Fuel pipes
« Reply #1 on: November 25, 2004, 00:21:02 »
I'm sure that if you contact any of the regular parts suppliers, they can help you out with all the specs etc. I recall some advice that these ought to be replaced once every X (not too many) years, although in speaking to someone who did recently, it sounds like an involved job, since apparently the pipes are not (all) pre-bent and you have to do some of this yourself?

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Cees Klumper
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Malc

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Re: Fuel pipes
« Reply #2 on: November 25, 2004, 06:37:41 »
Mikey,
Not sure which country you are in but I have replaced fuel pipes on cars with the following (cheap  :D ) alternative, seems to work and I have had no problems with the MOT test (vehicle inspection) in the UK

Check pipe diameter, but I suspect it will be somewhere around 8 to 10mm

Go to your local plumbing and heating supplier

buy a roll of "microbore" central heating copper pipe (8-10mm) and a suitable sized pipe bender.

If you haven't a flaring tool to make the ends where the rubber fuel hoses fit you can buy "olives" and carefully solder them on to the pipe once you are happy with your new pipes

You can bend it by hand and of course it is much more corrosion resistant than steel, yes it's abit softer but I have had no problems in my MGA.

A more expensive supply is to use what I know as "Kunifer" pipe which is a harder copper alloy (and difficult to work). The best place to get this in a roll is from a lorry garage/parts supplier.


HTH
Malc

 


Mike Hughes

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Re: Fuel pipes
« Reply #3 on: November 26, 2004, 15:22:41 »
Just an observation:  I'm sure that the exact length of the pipes from the IP to the injectors must be critical to the actual timing of the fuel pulse at the injector, so it would seem prudent to try to reproduce those pipes as true to the original length as humanly possible.

- Mike Hughes  -ô¿ô-
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- Mike Hughes  -ô¿ô-
  1966 230SL Auto P/S
  Havana Brown (408)
  Light Beige (181)
  Cream M-B Tex (121)

mdsalemi

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Re: Fuel pipes
« Reply #4 on: November 26, 2004, 17:05:59 »
Malc,

Are you not aware that BMC-Leyland changed from copper fuel lines to steel in the mid 60's?  You don't have problems on your MGA simply because you don't drive it regularly I would guess...but the change was indeed made for safety reasons.  I vaguely recall changing the fuel lines on my old Cooper S from Copper to Steel.

Copper gets "work hardened" from flexing; the flexing can be gross or minor; but it is present from shock, vibration, etc. happening in your car regardless of how well damped it is.  When the fuel line get hardened, one final "straw on the camel's back" will snap the fuel line.  That's exactly why BMC changed and why fuel lines today are steel.

There is a temptation to use copper because it doesn't rust.  However that would be inviting trouble.  Stick with steel.  Fuel line and fittings are relatively inexpensive.  One can purchase pre-made fuel lines from MB (don't know if all of them are available) and you can also purchase flaring tools and straight fuel pipe and fittings from most auto parts stores that will fit your car.

The last thing any of would like to read about is one of our fellow member's car up in flames because of a fuel line snapping!

Michael Salemi
1969 280SL
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Restored
Michael Salemi
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Malc

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Re: Fuel pipes
« Reply #5 on: November 29, 2004, 04:15:21 »
Michael,
I ended up using "Kunifer" on the 2002Tii which is stronger. It's used on lorries for air brakes etc over here so if it's accepted in the commecical world I recon' it's ok.
It's a bit harder to work, but on last inspection they were ok. 3 years 35000 miles

MGA pipes (copper) are still ok after 5 years and 25000 miles however they are well supported and the connections to rubber pipes are supported too, so they don't suffer from fatigue.

Agree the best way to do it is to buy pipe and make your own (whatever material) as preformed from a supplier are very expensive for what you get and they never seem to fit anyway!

Malc

mdsalemi

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Re: Fuel pipes
« Reply #6 on: November 29, 2004, 06:54:18 »
Gents,

The choice to use copper, steel or this UK product called Kunifer is entirely up to you of course.  Kunifer by the way, is a 90/10 alloy of copper and nickel--devloped to overcome the problems with copper.  It is used nearly exclusively in UK and Europe and nearly unheard of in the USA.  The problem with copper is that it works until it doesn't.  Here a quote from someone describing a rebuild on a Mini:

"I had the long front-back brake pipe made up in copper and was in half a mind about the ones in the engine bay until one snapped when I moved it slightly (more like fell apart), so the decision was made for me. It is actually only about £20-30 for the whole set to be made up, don't trust old pipes even if they look OK."

Similarly another quote from another UK rebuilder:

Pure copper tubing work-hardens and becomes very, very brittle- especially at flare fittings. Under the cyclical loadings seen from brake applications, and in the presence of moisture (and possibly high concentrations of chlorides, if you live in a road salt area), they will almost certainly fail. They will tend to crack and fail right at the flare, generally with little or no warning. (Copper also catalyzes the auto-oxidation of fuel, the mechanism of sludge formation. Copper should never be in contact with fuel.)

Copper's day for fuel and brake lines has passed; but that doesn't mean you can't get it.  In fact there are a variety of suppliers that make copper fuel line kits for Triumph, Jaguar, MG, Rover and other British Marques.  But you won't have to do much research to hear the bad news about copper, and the good news about Kunifer as a replacement.  But as long as you know what you are getting into so you don't have any surprises down the road, you should choose what you want.

Hope this helps.


Michael Salemi
1969 280SL
Signal Red w/Black Leather
Restored
Michael Salemi
Davidson, North Carolina (Charlotte Area) USA
1969 280SL (USA-Spec)
Signal Red 568G w/Black Leather (Restored)
2023 Ford Maverick Lariat Hybrid "Area 51"
2023 Ford Escape Hybrid
2024 Ford Mustang Mach Ex PEV