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MG MGA - Replacement fuel pipe

I'm just in the process of replacing the battery lead from the battery through to the starter switch after finding that is made up of lots of odd bits and pieces of various thicknesses cable. I'm going to fit some much thicker cable which will hopefully help sort out the occasional starting problems I have experienced.

The cable runs alongside the main fuel pipe that runs from the fuel pump, alongside the chassis rail through to the carbs.
The fuel pipe is a fabric covered flexible type and it has already had to have a section replaced as it had developed a crack where it bent around below the rear bulkhead.

So whilst I am sorting out the cable, I am looking to replace this hose with something that is more ethanol resistant, ideally re-enforced to withstand any stones flying about under the car.

Has anyone any suggestions as to what type of fuel pipe I should buy?

(I am going to keep with flexible fuel pipe and it needs to be 8mm internal diameter.)

Cheers
Colyn
Colyn Firth

What's wrong with the original type hard line. I've had over 30 years service out of mine so far. More than ethanol and stone resistant.... I am also still on the original battery to starter cable...
Dominic Clancy

Thanks Dominic,
the battery cable was obviously a DPO lash-up and it needs sorting out once and for all.

I probably could have made do with the fuel pipe for a while longer yet but I thought, if I am going to take most of the cable fixings off, probably with most of the fuel pipe fixings at too, then I may as well replace the fuel pipe at the same time.

My car was a race car just as I bought it and so I believe that the bigger fuel lines had had been put in to supply the race engine. I think I will probably need a similar size pipe to supply this 140 bhp 1950cc engine.

I also think it would be easier to replace the flexy fuel pipe with a similar type and hopefully of better quality, than to fit metal pipes.

Cheers
Colyn

Colyn Firth

1.) The largest battery cables you could cram onto your MG may be good for about 0.06-volt gain for the starter motor under the most optimistic conditions. Does that seem worth the effort? See the tech here:
http://mgaguru.com/mgtech/electric/ss_103a.htm

2.) Soft fuel pipes underneath the car is probably a bad idea as a matter of safety. So I will not make any recommendation on appropriate hose (because there isn't any). If you want larger fuel pipes, then install larger metal pipes. Metal pipes have thinner walls, so a 5/16" metal pipe takes no more space than a 1/4" hose.

3.) Figure out how much fuel flow you need first, and you may discover that you already have enough flow. If you want to assure more fuel flow capacity, then install a fuel pump that will deliver the flow you want at slightly higher pressure, which will have no problem pushing more fuel through the standard size pipe. Then install a fuel pressure regulator up front near the carburetors to regulate the final pressure to suit the carburetors.
barneymg

Thanks Barney
looks like I need to re-think the fuel pipe issue, I don't know so much about metal fuel pipes and so I will look into it.
Can I get metal pipe which is flexible enough to be bent around the sharper corners on the chassis/body without kinking?

PS
The old battery cable is made up of about 5 sections of thin and thick cable all joined together with screw connectors (not soldered) and so I am hoping that a new thicker single piece of thicker cable will help here.

Cheers
Colyn
Colyn Firth

My Moss catalogue is still showing this long fuel pipe as available (AHH5288)and tank to pump (AHH5290). Replacing all those bits of starter cable with those, probably corroded, connectors should make a big difference. My car has an added large earth cable from the chassis to one of the bell housing bolts, which can only help the braided earth wire up front. It all helps.
PeteT
PeteT

Colyn

Barney has summed up my configuration. As you know I run an 1800. I put a Facet pump in during the rebuild. Its supply pressure turned out to be too high for the SU carbs so I installed a Fuel King regulator and turned the pressure down. I bought a screw in pressure test gauge suitable for the Fuel King. Welcome to borrow.

Steve
Steve Gyles

Colyn
The standard fuel line fills all your needs. Its bore is much larger than the jets, so if the pump is delivering pressure, there will be enough in the float chambers. The new ones are made from a copper alloy of some sort, so bend easily and can do sharp corners with care and the right tool
Dominic Clancy

Colyn
8mm pliable copper gas pipe works a treat and no tools needed for bends. I used double clipped braided hose, with olives soldered in place, to connect to the fuel pump to provide scope for movement on the flexible mounting.

Regards
Colin
Colin Manley

Thanks Colin,
that sounds like the way to go, I have got an 8mm spring type pipe bender and a pipe cutter somewhere in amongst my plumbing kit.
Will let you all know how it goes.

Cheers
Colyn.
Colyn Firth

I did same as Colin, soft copper 3/8" from a HVAC place
Art Pearse

Colyn

See the eBay item number:

112766408054 ends tomorrow Saturday might be worth a look?

Regards

Mark
M Dollimore

Colyn
see eBay item number:

112766408054
Might be of some use.

Regards

Mark
M Dollimore

kunifer would be better, copper work hardens and then breaks/splits...
David k Brenchley

Thanks everyone, I have just ordered some 8mm Kunifer (Copper-Nickel) pipe to replace the old rubber stuff.

I will soft solder some olives at each end to help locate the flexy pipes that I will have to fit at each end.
These are to connect to an in-line fuel filter that I have fitted just after the fuel tank and to the fuel pressure regulator that I have fitted on the front bulkhead next to the Weber carb at the other end.

Will post some pictures when I have done the job.

Colyn
Colyn Firth

I replaced my steel fuel pipe with copper about 5 years ago. If I was doing it again I would use Kunifer even though the copper still looks good. I replaced the steel pipe as it was looking quite badly pitted so I renewed it as a precaution. As an experiment I sawed the old steel pipe across the worst looking area and there was actually a substantial amount of metal left, probably enough for about another 40 years.

More serious was that the fuel line had for many years been rubbing against a brake line and had put quite a groove in it. It was completeley hidden and could only be seen after the fuel pipe was removed. The brake line is replaced and they are now well separated.

Malcolm
Malcolm Asquith

Just as an aside to this thread, in Australia the so called Copper Nickel (Kunifer) is banned. Some idiot back in the 1950's decided that copper (as was available then, and now) was too soft for Australian outback conditions and Australian metal roads in general. Even though stronger metal in the form of Kunifer has been introduced around the World, Australian authorities refuse to re analyse the benefits. A lot of us import the Kunifer to use, even though the "rules" say steel pipe must be used. What most of the so called Government Dh's don't realise is that Kunifer is almost totally used on all European new imported vehicles..Mercedes, Porsche, Alfa etc.etc. So go figure that out!
Gary Lock

4 AWG cable (welding shops have rolls of it) works. If you are really worried about protection, you can run it inside some steel conduit, but it really shouldn't be necessary.
Bill Spohn

Thanks Bill
I have gone for 40mm2 cable which is advertised as good for 300 amps.
As best I can find out, this is equivalent to 2AWG gauge.

This new cable has a much bigger cross sectional area than most of the present cable which is 25mm2 (4 AWG).

By most of the cable, I mean that the present battery cable had been been assembled from about 4 sections of different thicknesses, all joined by screw connectors.

I have some tough spiral plastic binding that I will wrap both the cable and the new fuel pipe up in when I fit them under the car.

Cheers
Colyn
Colyn Firth

My car still has the original battery to starter cable, fitted without any protection. The fuel line has been beside it for 30 years since the restoration, also without any protection. neither show any damage at all, and the wiring loom is and brake line are also fine. I suggest any extra protection is unnecessary and will only trap water and dirt.
Dominic Clancy

I think you may be correct Dominic,
I suppose I was probably just going to repeat what had already been fitted to to the car when i got it.

It had been a hill-climb race car and i would think that the extra cable and pipe protection had been fitted to help against the occasional "off-road" moment that happens in that sport.
Colyn
Colyn Firth

Colyn

Please excuse my general ignorance on all this, but just spotted that you intend to soft solder the olives. Something at the back of my mind says that soft solder is attacked by modern fuel. Should you be better brazing them?

Steve
Steve Gyles

I had thought about the modern fuel/soft solder issue Steve,
I remember speaking to Peter Burgess about this when he used soft solder to fill up and re-drill the jets on my Weber DCOE and I asked him if the fuel would dissolve the soft solder?

He half smiled and said "Yes it will", then he told me that it may take 25 years or more for me to notice any difference!
In practical terms that will make me 93 years old before it starts to run a bit rich!

I had planned to soft-solder an olive onto the pipe an inch or so along from the end which would act as an anchor point for the hose-clip on the flexy fuel pipee that I intend to use at either end.

I now have plenty of cupro-nickel pipe to play with as they sent me 25 ft of it, so I will experiment with both brazing and soft soldering the olives to see which works best.

I also have in my garage a pipe flaring tool that a friend gave me which I will experiment with to see if I can use it to flare the end of the cupro-nickel pipe.

This could the simplest solution if I can only figure out how to use it :-)

Cheers
Colyn

Colyn Firth

Just to a progress report you on this.
I just had a bit of soldering practice on the cupro-nickel piping to see what sort of mess I would make of it. The idea being to try both silver soldering and soft soldering to see which worked best.

I decided to try silver soldering first (sweating in USA speak), I first tried it with a little gas blowtorch that I use for plumbing, it was obvious that the torch wasn't really powerful enough.

I did eventually get the solder to run but it looks a bit messy and the lumpy finish may not lend itself to sealing against a flexy fuel pipe.

For my 2nd attempt, I used a proper propane gas brazing kit, the heat output was obviously much better and the solder ran into the olive almost instantly. I used a borax based flux.

I did then make a couple of attempts at soft soldering the olives but these were a total disaster, I just couldn't get the solder to run at all and it ended as a sooty mess. ( yes i did use plenty of soft solder flux and everything was shiny clean when I started). I then ran out of olives and so I will give this another try later.

To be honest, the silver soldering went so well that may just go with that.
I just need someone to tell me how to get the borax flux off the finished job.

Cheers
Colyn

PS
I just looked at my last post and re-reading it, it maybe comes across as maybe a little sarcastic, it wasn't intended. Apologies to Steve Gyles🙁

This picture is my 1st attempt at silver soldering


Colyn Firth

This is the 2nd attempt which I am quite happy with.
Just need to find out how to get rid of the melted flux on it.
Colyn

Colyn Firth

Not in the slightest Colyn. I raised a query and you explained that you had also raised it with an expert. That's what forums are all about.

Cheers

Steve
Steve Gyles

AFAIK there is no need to solder or braze these olives. Compression seals the joint.
Art Pearse

You are correct Art,
but I am not using a compression fitting in this instance.
I plan to solder the olives on to the pipe about 3/4" along from the end so that when I slide a piece of flexy fuel pipe over it to connect to my fuel pressure regulator, the olive will act as something solid to clamp the flexy pipe onto.

Hope that explains things.

Colyn
Colyn Firth

Colyn
Yes, the reason for the use of olives was understood. I use two clips on each join, one either side of the olive; the inner clip acts as the 'stop', preventing the hose from coming off, in addition to providing a seal and the outer clip is a secondary seal.

Regards
Colin

Colin Manley

Colyn, after the solder flows,no matter which type you use, wipe your work with a wet piece of towel or paper towel. When it's still hot you can clean it up nicely. If you have to reheat and do it again. I used copper pipe to extend my carb overflows. Originally they were steel,copper to me did not look right. I cleaned the pipes melted solder on to the complete pipes and wiped them down- they look just like the original steel ones now.
gary starr

Steve
Just a note in defence of the Facet pumps
There are several differently rated Facet pumps and selecting the correct (low pressure - high flow)pump to suit SU carbs eliminates the need for a pressure reg.
William Revit

William

I was told by the supplier that the Facet pump I bought during my rebuild back in 97 was suitable for our carbs. Over the years I struggled to tune out the slightly rich running. Eventually I installed a Filter King; again apparently suitable for our carbs. Still I could not tune the carbs to what I considered perfection. Eventually I bought a pressure gauge for the Filter King and noted a very high pressure output (4 psi). Turned the pressure down (1.5 psi I think) and most of my problems went away, albeit still slightly rich. 4 months ago I put in new jets. Hey presto. The old jets had supposedly been new when I bought the reconditioned carbs in 97. I have my doubts.

Steve
Steve Gyles

I titled this thread "Replacement fuel pipe" and then my first words immediately went off thread talking about my battery cable.
So I hope you don't mind me updating you on the new cable which I have now fitted.

When I had a proper look at the old cable I discovered that it had actually been routed beneath the transmission tunnel, coming inside the car at the front of the bell-housing cover next to the front bulkhead.
This routing was chosen to bring the cable to a battery isolator switch which had been fitted under the dashboard.
( this is one of the remaining modifications from the cars racing days before I owned it)
The isolator switch is quite convenient just there and so I have stayed with this routing.
I have attached a picture which shows the difference in thickness between the old cable and the new thicker cable.
The copper wire in the old cable is 5.00mm in diameter as compared to 7.3mm in the replacement cable.
Hoping that it makes the starter motor a bit more lively.
Cheers
Colyn


Colyn Firth

This project started out as a simple battery cable replacement. Then I thought I had better replace the fuel pipe as I assumed that it ran alongside the battery cable next to the Right side chassis rail.
(The flexy fuel pipe had cracked last year and had a section replaced)
But the job just keeps on growing!

What I had assumed was the battery cable was in fact the wiring loom! and the cable had been routed inside the transmission tunnel. In my defence, all the cables and pipes on my car are wrapped in a black plastic spiral covering to protect them and they all look the same.

So I have now sorted out the cable and I was just connecting the front end of it to the solenoid (my car has a solenoid instead of the original pull switch), when I found that the threads were all stripped on the solenoid terminal!
So a new solenoid needed!

I wonder what else will add itself to the to-do list as I go along☺!

I haven't even started to fit the fuel pipe yet!

Colyn


Colyn Firth

This thread was discussed between 24/01/2018 and 07/02/2018

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