Replacing Copper Fuel Lines
Discussion
Hi All
Am now getting on fairly well with my Chims body off/ chassis refurb and my next task is to renew the old copper fuel lines. However, I am not sure where the optimum place should be for the copper lines to terminate and the engine fuel rail flexibles to start; so that there is sufficient access to routinely replace the flexibles in future.
The old pipes do not help, as the pump pressure line in particular ended up vaguely behind the bell housing and was not clipped or cable tied just swinging in the breeze! The old return line pipe is better and terminated about half way up the bellhousing on the off side.
Any prior experience and wisdom would be greatly appreciated.
Am now getting on fairly well with my Chims body off/ chassis refurb and my next task is to renew the old copper fuel lines. However, I am not sure where the optimum place should be for the copper lines to terminate and the engine fuel rail flexibles to start; so that there is sufficient access to routinely replace the flexibles in future.
The old pipes do not help, as the pump pressure line in particular ended up vaguely behind the bell housing and was not clipped or cable tied just swinging in the breeze! The old return line pipe is better and terminated about half way up the bellhousing on the off side.
Any prior experience and wisdom would be greatly appreciated.
A similar post recently someone suggested doing them front to back in one run of high quality stainless braided hose which sounds a good idea to me.
Id have preferred to see the existing copper brought up into the engine bay somewhere near the back but not sure this is possible. I recently replaced my return line and stopped the copper a little lower down than before due to access but at least i can get to the pipe clip if needed in the future.
Id have preferred to see the existing copper brought up into the engine bay somewhere near the back but not sure this is possible. I recently replaced my return line and stopped the copper a little lower down than before due to access but at least i can get to the pipe clip if needed in the future.
caduceus said:
I too just took out all my old copper brake and fuel pipes today, and was wondering the same thing. I don't want the fuel pipe route to go over the gearbox again. Not the best of places to put it.
Does it matter how long the copper length/route is, as far as pressure goes?
I want it to go over to nearside after the filter and then straight to engine bay, instead of offside and then cross over bellhousing!Does it matter how long the copper length/route is, as far as pressure goes?
An "off the wall" possible solution is have a join in the copper using an 8mm small bore central heating joint at the point where the pipe disappears up the firewall; you could undo this and withdraw the flexible with a short length of copper from the engine bay. [ worth a feasibility study ]
If it were me I'd be making the run in solid fuel pipe as long as possible and the flexi hoses as short as possible.
Flare the ends of your solid pipes, join your "short as possible" flex hoses using proper petrol clips (not Jubilee clips) and rout them away from the exhaust manifold to avoid fuel vaporisation.
Make sure the flexis are also routed away from the exhaust or any other source of combustion/high heat ensuring the ends are easily accessible for future flexi replacement.
No flexi is as safe & strong as a solid fuel line, Cunifer is a good material that lasts for ever, it's also easy to bend and flare.
Stainless steel solid pipe is an option put is much harder to work & flare, PTFE lines seem to be the modern solution and I run my LPG through PTFE lines from my boot mounted tanks right to the vaporiser mounted on the front chassis crossmember.
A quality automotive PTFE fuel line is ideal for coping with modern petrol which is now full of corrosive ethanol, it's flexible and in theory should last for ever.
Good automotive PTFE line is flexible, is designed to handle the high pressures of modern non-return injection systems, rated from -40°C to +232°C and is completely unaffected by ethanol.
PTFE lines can't corrode and are available in many different overbraids from stainless to Nomex.
PTFE is the modern choice so perhaps the ultimate solution would be to have the feed & return lines as long as possible in semi rigid PTFE, with the ends made up in a more flexible PTFE hose.
Here's a guide to installing decent end fittings to PTFE lines:
https://www.youtube.com/watch?v=jJpafJYjjak
Flare the ends of your solid pipes, join your "short as possible" flex hoses using proper petrol clips (not Jubilee clips) and rout them away from the exhaust manifold to avoid fuel vaporisation.
Make sure the flexis are also routed away from the exhaust or any other source of combustion/high heat ensuring the ends are easily accessible for future flexi replacement.
No flexi is as safe & strong as a solid fuel line, Cunifer is a good material that lasts for ever, it's also easy to bend and flare.
Stainless steel solid pipe is an option put is much harder to work & flare, PTFE lines seem to be the modern solution and I run my LPG through PTFE lines from my boot mounted tanks right to the vaporiser mounted on the front chassis crossmember.
A quality automotive PTFE fuel line is ideal for coping with modern petrol which is now full of corrosive ethanol, it's flexible and in theory should last for ever.
Good automotive PTFE line is flexible, is designed to handle the high pressures of modern non-return injection systems, rated from -40°C to +232°C and is completely unaffected by ethanol.
PTFE lines can't corrode and are available in many different overbraids from stainless to Nomex.
PTFE is the modern choice so perhaps the ultimate solution would be to have the feed & return lines as long as possible in semi rigid PTFE, with the ends made up in a more flexible PTFE hose.
Here's a guide to installing decent end fittings to PTFE lines:
https://www.youtube.com/watch?v=jJpafJYjjak
Aussie John said:
An "off the wall" possible solution is have a join in the copper using an 8mm small bore central heating joint at the point where the pipe disappears up the firewall; you could undo this and withdraw the flexible with a short length of copper from the engine bay. [ worth a feasibility study ]
Sounds like a good idea to me, would allow a piece of copper pipe to be taken further into the engine bay. Easy to remove too if the body ever needs to come off.Edited by ch427 on Sunday 22 February 10:05
Edited by ch427 on Sunday 22 February 10:06
Thanks to everyone who contributed to this thread. Just installed my new fuel lines. Decided to go for Cunifer pipe as it is a tougher material than soft copper. It is harder to work with, but I bought a small pipe bender and that did the trick on the sharp bends. I deliberately terminated the pipe ends half way along the bell housing behind the RH bank cylinder head. Everything is a compromise between trying to keep the flexibles as short as possible, but allowing sufficient access for regular changes. The flexible pipes joints and clips are now high up but still accessible from underneath. It is certainly a far more satisfactory arrangement than that previously in place.
Got the proper clips on order.Gassing Station | Chimaera | Top of Page | What's New | My Stuff