The Triumph Dolomite Club - Discussion Forum

Hi,

Hopefully a nice easy one this....

Could somebody confirm the correct size copper tubing required for the Sprints fuel lines.

Many thanks,

Chris.

Firstly, I don't use copper for this,
it is kunifer that I use. The size being 8mm. That is tank to pump.
(The hose for the bits at the carbs is smaller, being 1/4" bore.)

You need to be careful with the rubber sections, ensure you get something suitable for petrol containing ethanol.




Ian.

A question for sprint95m? Is their a specific reason why you did not use copper as I used 8mm micro bore central heating pipework when I had to replace the rear section on one of my car's as it was readily available and easy to bend?

I would suspect its because copper pipes tend to crack under vibration. You dont get so much of this in a domestic heating
environment whereas you do in a few places where the fuel pipe goes...

Steel was OE....for a reason.

Jonners

If the fuel pipes are nicely clipped, I see no reason why copper cant be used. Ive had mine on for a year now so we'll see. Central heating probably does vibrate in most houses too. I wont use copper on brake pipes though.

Tony

Thanks for the advice on this,

This copper subjects a little confusing, I'm in the process of fitting all new copper brake lines!! So does this mean I've got to strip it all out and do it again?

How come copper fractures? If I where to constantly bend a copper pipe and a steel, I'd expect the steel to snap first!

The 3/16 copper pipe I'm using does have a British standard number stamped all over it.

Will see if I can source kunifer for the fuel lines.

Chris.

I've been using 8mm microbore central heating pipe as fuel line for years, not only on my own cars but on many customer vehicles too, including those fitted with high pressure fuel injection AND LPG systems. I've yet to have any failures - at all - ever!

I agree with the use of Kunifer for brake lines, especially those attached to the sliding cylinders on the rear of Dolomites. But a properly clipped up fuel line is not in the same league!

Steve

Chris the brake pipe issue is more about twisting. When the joints are tightened and the nut grips (due to the cone angle), the pipe can twist as it gets fully tightened. This can stress the pipe a bit. Also using copper with steel fittings causes corrosion/electrolysis so if you try to undo them in a couple of years to remove a wheels cylinder for example, the pipe can twist as its stuck in the nut.

I got some 8mm (5/16) kunifer fuel pipe recently to replace OEM rusty ones from a motor factors, not cheap though.

Tony

I can see what you mean Tony, I did have a car a while back where the copper pipe had corroded to the union, I had to make up an entire new pipe. I finished them today in kunifer.

After spending some time today trying to establish where all the fuel line clips go I'm now faced with the scary task of trying to make up new lines. I had my original which I was going to copy as they where undamaged, but someone at work threw them away!!!! so now I've got to try figure it all out. I got 5/16" kunifer, boy is that stuff almost impossible to bend!

Perhaps you could let me know if you're aware of any good photos that show exactly how they run and where the bends are.

Chris.

Ah losing the originals is a bugger. they are a complicated shape(s). I dont have pics sorry. On one of my cars, I ran the pipes down the drivers side to make it neater. They only go down the pass side because its for OHV cars withe the pump that side and the over the tunnel section was added for slants so if youre feeling brave going down the drivers side is a lot less bends to do. I used a hand held bending tool which made it a lot easier.

Tony

James has kept his original fuel lines...

Carledo wrote: I've been using 8mm microbore central heating pipe as fuel line for years, not only on my own cars but on many customer vehicles too, including those fitted with high pressure fuel injection AND LPG systems. I've yet to have any failures - at all - ever!

I agree with the use of Kunifer for brake lines, especially those attached to the sliding cylinders on the rear of Dolomites. But a properly clipped up fuel line is not in the same league!

Steve

Totally agree with Steve, it's a complete waste of time and money using Kunifer on fuel lines. RUK's are exactly that, 8mm central heating microbore the same on my Frontline MG Midget just copper fuel lines everywhere. There are no screw unions on the fuel lines, its all rubber hose joins.

Brakes - oh yes, fuel lines why bother. If one does break and I've never ever heard of a copper fuel line breaking (except one of the steel ones because they were rusted through) all that will happen is the car will stop and there'll be fuel on the road.

Oh and I do have my complete set of steel lines safely stored away, have a look on my thread and you'll see. If I get the chance today I'll dig them out and take some photos.

Tip for flaring the 5/16" tube is to anneal it before attempting the bubble or double bubble flare.
Heat with a butane torch until just glowing red then I quench in a bucket of water. Also, depending on the tool you are using chamfer the outer edge and deburr the inside.
Also, use the punch grease as well otherwise it might deform and pucker the tube.
Oh and copper is illegal to use for brake and fuel here in Aus. Copper can work and age harden making it very brittle but..as others have said it's used elsewhere with little issue so I guess you pays yer money you takes yer choice.

Cheers

sprintchris wrote: ↑Sun Jun 18, 2017 1:00 amI got 5/16" kunifer, boy is that stuff almost impossible to bend!

I use an inexpensive pipe bender like this
http://www.ebay.co.uk/itm/Rothenberger- ... SwwzhZPZQw
except mine is black and came from Machine Mart.


Some time ago I had an Eastwood one, which was possibly a little better,
but alas I lent it to someone and never saw it again .



Ian.

Interesting reading everyone's comments. I don't know how I can flare the ends of the 8mm.... Out of curiosity, all modern cars I work on have plastic fuel lines, has anyone ever tried fitting them?

I didn't realise OHV models had the pump on the nearside, I'll have another look, see if there's holes for the clips on the offside, there did seem to be some redundant holes....