Lotus Elan

What type of rigid fuel line should I use?

PostPost by: TroonSprint » Sun Jan 27, 2013 5:27 pm

Starting to gather the bits for building up my chassis, and I am confused over the best type of rigid fuel line to use. There is much written about the introduction of ethanol containing fuels and their incompatibility with various metals and plastics. So will Kunifer pipe be OK, or should I go for Teflon/PTFE, or something else? Anybody out there got the answer?

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PostPost by: cliveyboy » Sun Jan 27, 2013 6:17 pm

Mike
If I was doing a body of restoration I would use stainless steel tube through the chassis.
As I was not taking the body off on my sprint the flexible tube that runs down the chassis is pretty inaccessible.
I therefore ran copper pipe (copper nickel mix) underneath the car. The chassis has a small lip on the bottom of the chassis where the fuel line can sit flush and not protrude. I used rubber hose at the fuel tank end and ran the copper up to the engine bay. You need some flexible hose to connect to engine to allow for movement of the engine.
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PostPost by: billwill » Sun Jan 27, 2013 6:54 pm

See page 7 of my topic
lotus-elan-f19/getting-ogu-roadworthy-again-t26101-90.html
showing how I have replaced a long rubber fuel tube (which was smelly) with a copper-nickel rigid pipe.

It runs under the right hand door inside the cabin. I used a PVC flexible pipe to join to my electric pump in the boot, but I had only a nitrile rubber one of the right size to join the rigid pipe to the fuel pressure regulator under the bonnet. I will be keeping an eye on that for ethanol damage.

If ethanol attacks copper or copper nickel piping there will be an awful lot of brewing liquor stills that would have failed by now. :shock:

I don't think there is any chance of ethanol attacking copper or copper nickel. 8)

~~~~~~~~~

Fuel pipes on modern cars are stiff nylon, which are a (hard) push fit onto barbed connectors. The connectors seem to be some sort of quick connect/disconnect.
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PostPost by: billwill » Sun Jan 27, 2013 6:57 pm

Does anyone know what alloys Kunifer is?

It sounds like Copper Ferrous, i.e. Copper and iron, but are those two alloyable at all?
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PostPost by: mikec2126 » Sun Jan 27, 2013 7:02 pm

billwill wrote:Does anyone know what alloys Kunifer is?

It sounds like Copper Ferrous, i.e. Copper and iron, but are those two alloyable at all?



Kunifer is 90% Copper 10% Nickel....
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PostPost by: billwill » Sun Jan 27, 2013 7:04 pm

mikec2126 wrote:
billwill wrote:Does anyone know what alloys Kunifer is?

It sounds like Copper Ferrous, i.e. Copper and iron, but are those two alloyable at all?



Kunifer is 90% Copper 10% Nickel....



Thanks. It's annoying when names are misleading. They should have chosen Cupronick or something like that as the trade name.
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PostPost by: rcraven » Sun Jan 27, 2013 7:46 pm

Kunifer is in fact sometimes spelt Cunifer, and I think the "fer" bit at the end means that it can (sometimes) contain iron as well as copper and nickel. If you start Googling it, you'll find varying percentages for its constituents.
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PostPost by: TroonSprint » Sun Jan 27, 2013 8:02 pm

Thanks for your comments. The reason I ask is because there seems to be quite a long list of materials that aren't recommended for use with ethanol containing petrol. Have a look at this article from the MGCC V8 Register http://www.v8register.net/articles/Burl ... 281111.pdf (I also own an MGB V8).

They asked Burlen (the SU carb people) for their take on the issue and this is what they said. If you scroll down to page 2 there is a table of materials you can use and those you should avoid. Zinc, brass, copper and nylon are all supposedly attacked by E10 and stronger mixes of ethanol. Reading other sites leads one to think that there are very few "rubber type" pipes that will be safe. On a VW camper web site and also on the Reliant Scimitar web site there are horror stories of fuel hoses weeping or splitting leading to catastrophic vehicle fires. Our Lotuses are prone to fire, especially with the fuel hoses near to the distributor, so I intend to try and use the right materials.

Here in the UK we don't have E10 yet, but its coming, and who knows what we will have to put up with in future years. Personally I think its crazy to grow crops to make car fuel when half the world hasn't enough to eat. It is also crazy to make a fuel that is less efficient than gasoline so that we have to use more of it. We might cut the gasoline content down to 90%, but then if you need to burn more you have cancelled out the benefit.

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PostPost by: bcmc33 » Sun Jan 27, 2013 11:07 pm

The fuel feed and return pipes from the engine bay to the boot in my car are copper. The flexible pipes in the engine bay and boot are "high quality standard" type fuel line hoses. Big mistake on the flexible hoses as I believed them to be Teflon cored - the smell in the boot when closed for some time shows they are not Teflon cored. Bought some Teflon cored hose as replacement, but have never got around to do the job. :oops:

However, experience from a small fire in the engine bay of a friend's Esprit showed some important information - namely, the standard type hose burns very easily. He had two sets of flexible hose fitted side by side - the standard type hose burnt almost to the core, and the other hose was virtually untouched. The other hose was a Goodridge product, but not suitable for a high pressure system like mine.

BTW, I am aware of the so-called bad effect that ethonol is supposed to have on copper, but I dose my fuel with Millers EPS.
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PostPost by: nomad » Wed Jan 30, 2013 8:08 pm

Here in the midwest US I've been burning E10 ethanol based fuel in British cars since the early 1980's. I believe, as here, there is a lot of scare info out there on this topic since I have had no bad experiences. Yes, I have had to replace a couple of hoses that were ancient and may have turned to mush anyway. If your fuel system is dirty and rusty you had better have good fuel filters in place and clean them often for a while but other than that I don't think you have to worry.
As to the whole question of food versus fuel I believe the main reason it was introduced in the US was as a replacement for MTBE in gasoline. The MTBE was shown to be a vigorous and persistent carcinogen that was beginning to be found in ground water.

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PostPost by: spanner » Wed Jan 30, 2013 10:50 pm

TroonSprint wrote: Our Lotuses are prone to fire, especially with the fuel hoses near to the distributor, so I intend to try and use the right materials.
Mike


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PostPost by: gearbox » Thu Jan 31, 2013 5:12 am

I've had some bad experiences with ethanol from gumming up my electric fuel pump to clogging up injectors. I've used stabil for winter storage, and every spring I find myself taking apart pumps and injectors and soaking them in Sea Foam (brand of injection cleaner) until they clean up. This is with a fresh full tank with stabil that has run through the system. Ethanol does react with copper, but at 10% I'm not sure how long it will take to do any serious damage. My question would be what is the plastic tubes that was OEM made from and do they react with the ethanol? I know a lot of the marine guys are switching over to Stainless when possible, but you will still need a flex section. Rubber hoses won't work unless there is a barrier. Any knowledge base out there?
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PostPost by: nomad » Fri Feb 01, 2013 6:55 pm

I know this is not the answer you're looking for but I never have used Stabil. Of course I'm talking about carbureted engines but I have often had cars stored for years and still got them to run well enough to get the tank down to where I can add fresh fuel. My storage regimen amounts to filling the tank so that the area inside the tank where water can condense is reduced and that is it. If the gasoline still smells a bit like gas rather than varnish it will burn. Maybe a little black smoke and you won't win any races but it will burn.

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PostPost by: gearbox » Sat Feb 02, 2013 3:48 am

nomad wrote:I know this is not the answer you're looking for but I never have used Stabil. Of course I'm talking about carbureted engines but I have often had cars stored for years and still got them to run well enough to get the tank down to where I can add fresh fuel. My storage regimen amounts to filling the tank so that the area inside the tank where water can condense is reduced and that is it. If the gasoline still smells a bit like gas rather than varnish it will burn. Maybe a little black smoke and you won't win any races but it will burn.

Kurt.


Stale fuel burning is not the issue, I have aviation gas without ethanol that sits around for a while with no issues, but something about the pump gas with ethanol causes it to gum up with a brownish sticky subtance over a short period of time (6 months). I have a 71 Porsche 911S and the fuel pump is always getting stuck. If I'm lucky, I could tap on it to get it started and run sea foam through it, if not, I have to remove it, disasseble the pump, use brake clean to wash away all the brown gunk and it does not come off that easily. It stays sticky and when you wipe it, you don't get all of it and when it drys it gets real hard. If it had gotten into the mechanical injectors or injector pump, that is a real pain, you have to soak the injectors for days and the pump requires pulling the unit and manually un stick all the injector pistons. The worst experience I had was on my Alfa Spyder. Car had a primary pump in the tank. the ethanol ate away at a 2" section of hose designed to be submerged in the fuel and turned it into mush. The tank was covered in that brownish goo, destroyed my fuel sender, or should I say dissovled parts of it away (the copper windings). The brown varnish covered the entire tank. And I have had this car for 30 some odd years and never had these problems before ethanol came on the scene. Even my carburated motors suffer with stuck needle valves and blocked passages in the carb. I use Avgas in my generators and motorcycle as they don't get used that often, but when I'm stuck with a full tank of gas, I use stabil and pray. But the plastic tubes in our cars are pretty hard and may not be affected by the ethanol, but not sure. There has been a lot of litterature on what reacts with ethanol and these tubes may be ok, or can be replaced with material Viton or Nylon. As I mentioned, most of the guys at my marina are replacing as much line with Stainless as possible and the flex line with that Gates barrier rubber hose made especially to counter the effects of ethanol. I'm trying to keep the car close to original, so would like to use some kind of plastic tubing, but don't want a crack developing in the line in the chassis down the road.
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PostPost by: nomad » Sat Feb 02, 2013 4:30 am

Sorry to here about those problems. I've never encountered that here in the midwest where, I assume, the alcohol is coming from.
Maybe you're getting South American alcohol that is still almost rum!!!
Not a plastics expert but by just looking at the original fuel line I would think it would stand up to it.
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