Hello all,
since my carburetors (HIF7) will be out of commission for quite some time while work on reassembling the engine keeps getting delayed, I am thinking that the time is right to look into a better solution than rubber pipes and screw clips to keep fuel flowing without leaking.
Is there such a solution, reasonably workable or am I forever condemned to find ways to fit small pipes into big pipes and vice versa, squeezing them and then praying in vain that fuel will not leak?
Thank you 
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That cannot be the original Jaguar configuration, Ericā¦?
Frank
xj6 85 Sov Europe (UK/NZ)
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Hi Eric
Are you talking about the pipework in the engine bay leading up to the carbs? The hose/pipe joints shouldnāt leak if properly secured with worm clips.
Frankie
Eric,
I coulnāt seriously speak of HIF7, but my HS8 setup is absolutely tidy. Yes, they are rubber tubes, yes, they will deteriorate over time, but using good quality tubes and correct clips there is no reason why good tubes arranged and fastened correctly shouldnāt last for a dozen years or more without any leak. On my car, all the fuel lines - metal and rubber - seem to be of identical diameters and fit snugly - even better than on my Spitfire.
The fuel lines would certainly not be my first area of modification. If anything, you might think about an overhaul of the carbs, their linkage and - my personal point of improvement - the cold starting and running device.
Good luck
Jochen
Ok then. I was just hoping there would be something more āengineeredā than pipes and plumbers clips
Traditionally fuel was supplied via copper pipes and fittings. I have replaced some of the ārubberā hoses in my S1 boot with cunifer. There are advantages and disadvantages and the metal plumbing needs to be carefully thought through. Providing high quality ethanol proof hose and quality clamps are used there should be no issue with the Jaguar designed installation as Jochen says.
Frankie
There are Aeroquip fittings, but these are more for high pressure applications, and your SU fuel pumps on a carburetter car are putting out only about 4 psi (27 kPa) so there really isnāt any need for anything other than rubber hose and screw clamps.
Are you having trouble finding inch sized hose in your metric countries?
Here is what XK120 and Mark V have, braid covered hose with 3/8" compression fittings.
Rob,
these braided lines sure look nice, and the braiding probably will protect against engine heat. Howās your experience with the rubber though?
In fact, the big ābutā - which I failed to spell out in my first post - is the often doubtful quality of the rubber tubes. In many cases Iāve seen original tubes in service for 20+ years before they ultimately fail. Unfortunately, the replacement tubes often donāt see more than three to five years before they fail again. The thing that really annoys me is that you cannot even decide whether to buy stuff good for 3 years cheap at 5 EUR/m or a quality product good for the next 20 years at 50 EUR/m. And to make matters worse, identical products all of a sudden donāt resist some additive or the quality just changes. Information matters and this information is hardly available.
Good luck
Jochen
75 XJ6L 4.2 auto (UK spec)
I see, it must be you got some poor quality rubber, or not fuel line quality anyway.
Here is what I used on the '74 XJ12 and '38 SS.
https://shop.advanceautoparts.com/p/carquest-bulk-hose-tubing-bulk-fuel-line-hose-3-8-i.d.-12-inches-cq24088/5193907-P?searchTerm=3/8"%20fuel%20line%20hose
The price is $2.13 per foot or 12 inches.
It seems to last many years, so much that I donāt think about it.
The length of time it will last depends on the environment, i.e. engine heat.
If that source is no good for you, here is another place that ships world wide.
Gee Rob, thatās dead sexy. Weāre did you get the Martha Stewart starter motor?
Yes, this is my point. Rubber WILL fail. There has to be something better.
Rubber rated for gasoline will last 20-30 years, is that not long enough?
There is corrugated stainless steel hose, used in beverage and industrial liquid and cryogenic processing and vacuum systems.
Iām with you re the push on connection Eric. On the HS 8s fitted to my car Iāve machined some 7/16ā AF fittings to attach to the supply tube on the float chamber. Two of these fitting are attached using Locktite, the other one with silversolder to test heat transfer into the float chamber top, no problem with the latter. For the fuel line ā 4 Teflon with the appropriate Aeroquip fittings.
Sensible use of two spanners is required, when connecting / disconnecting to ensure that the tube into the float chamber top does not turn.
whatever the make up of the clear plastic lines in my (and other 420G, MKX), and early S1 XJ ?, probably some other Jags, is very superior, 51 years old, and no sign at all it needs changing, same as in wrecks I have seen. It is a simple push fit over the barb fittings
I have seen this particular fuel line for sale for the listed application
Not quite correct to call it ārubberā - fuel hose has come a very long way in the last 20 years.
I have no affiliation with this company:-
Frankie
I think the white plastic hose is called āTygonā, basically nylon (?), also in E types.
I bought both good and bad injection rubber hose, both for ethanol, for roughly the same priceā¦ but there are name branded hoses that would hopefully do; and maybe even match the OEM quality just as Robās. Iād ask around for experience with name-brand hose in the area.
The lower quality hose was starting to crack within a year, so I replaced everything and marked the old to be used for siphoning only. I still check it every other week or so, but it looks good.
Jochen, I have seen the post on facebook, great weather, nice spot and cars!
David
Thank you Peter!
I am thinking of brazing screw-on fittingsā¦
Well, last time I checked, 51-year old fuel hose is no longer in stockā¦ 
Thanks Rob,
for the link and the information; weāve got no problem sourcing correct size tubes; as David Jauch confirmed my own experience itās just some kind of lottery whether you get the kind of quality you might expect after some 50 years of development or hit dirt ā¦ Flow of crucial information is hampered, unfortunately!
Best
Jochen
75 XJ6L 4.2 auto (UK spec)
Feel free to join us - we take a spin every first Wed each month usually 6.30 pm during summer months! And if your Jag is not around, thereās always seats to spare from MG TF(?) to Healey, Spitfire to Morgan+8. Just let me know ā¦
