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Fuel Line Routing

PostPosted: Thu May 12, 2022 8:19 am
by 111Robin
During restoration of my Plus 2 I found that the nylon fuel line was unconstrained within the tunnel, just waiting to wind its self around the prop shaft, nice work by someone previously. So I am considering a hard fuel line along the underside of the chassis, same as the brake line but on the opposite side, with flexible lines to tank and pump. Has anyone else done this ?. I'm not sure if the proximity to the exhaust will be an issue, requiring some form of heat shield for protection. I don't want to route the line inside the car.

Re: Fuel Line Routing

PostPosted: Thu May 12, 2022 10:49 am
by DavidLB
I ran mine inside the car as i fitted fuel injection used solid ethanol comparable tube

Re: Fuel Line Routing

PostPosted: Thu May 12, 2022 11:01 am
by 111Robin
Like I said, my preference is not to run them internally.

Re: Fuel Line Routing

PostPosted: Thu May 12, 2022 12:09 pm
by wotsisname
It should run along the chassis, above the propshaft , but within the backbone and exit to the pump which is the other side to the exhaust. I have a spyder chassis and I was able to replace mine with the body on. From memory the diff may have been out at the time. I used PTFE instead of nylon. you have to use an insert in the tube end to allow the ferrules to grip without distorting the tube. I re-used the original brass banjo, bolt, etc. If you use braided, I would also check the internal pipe is ethanol resistant.

Re: Fuel Line Routing

PostPosted: Thu May 12, 2022 12:27 pm
by HCA
You did well to do it with the body on! My admiration!
I wanted to do this with mine but gave up, especially as I am running twin fuel lines.

To the OP, yes you can do it, but easier with body off imo, but as he says above, quite do-able!

I took the easy way out and ran continual ethanol braided inside. Having said that, my body after all will be coming off soon so I may change to single fuel line and route a solid line in the chassis - lets keep each other informed re the ease..!

Re: Fuel Line Routing

PostPosted: Thu May 12, 2022 12:40 pm
by berni29
Hi

This may be of limited help to you, but I am today routing my +2's fuel line. the car came with a solid steel pipe so will be using that. It's a spyder chassis and I will route the pipe inside the backbone. Funnily enough the car has a braided brake pipe running front to rear, and I have routed that inside the backbone also. Its an ex race car that has separate master cylinders for the front and rear brakes.

It must be a better proposition than running lines under the chassis where it may be damaged by road debris or contact with a speed cushion or similar.

All the best

Berni

Re: Fuel Line Routing

PostPosted: Thu May 12, 2022 1:12 pm
by types26/36
111Robin wrote:During restoration of my Plus 2 I found that the nylon fuel line was unconstrained within the tunnel, just waiting to wind its self around the prop shaft,


The fuel pipe should be supported inside the backbone by running through a "P" clip, this prevents it from coming into contact with the propshaft.
The "P" clip is fixed with a screw from the top of the backbone but I dont think you can get to the screw with the body on.
Here is a pic taken inside the backbone.

Re: Fuel Line Routing

PostPosted: Thu May 12, 2022 1:19 pm
by 111Robin
Thanks, this is the issue, with the body on I can't secure it inside the tunnel hence the intention to route it as per the brake line. Perhaps this is easier on a Spyder chassis ?. I don't see it being an issue with regards mechanical damage, the brake line is routed this way and is perfectly fine in this respect. My only concern is heat from the exhaust so I may well look into a heat shield of some form. I don't like the idea of running it inside the car, doesn't seem safe to me in the event of an accident to have fuel spewing inside the car. I can see it's advantages on a race or rally car but not for me.

Re: Fuel Line Routing

PostPosted: Thu May 12, 2022 5:03 pm
by wotsisname
My spyder chassis has small metal tabs that act like a P clip. I was able to (just) get a screwdriver in, the spyder allows more access than the OE chassis. I wrap a little piece of rubber around the pipe before pressing the clip back up against the chassis. Braided would be more difficult for sure particularly above the diff area.
If you are worried about heat (vapour locks?) then maybe a wrap or reflective sleeve would help?

Re: Fuel Line Routing

PostPosted: Thu May 12, 2022 7:24 pm
by 10kph
I have replaced my nylon pipe with a modern chemical resistant 8mm plastic tube and all is fine. I had a bright idea of pulling the old tube out as the new one was attatched th the other end on an original Lotus chassis.
My irst problem was that the original pipe seemed to be stuck and just stretched without moving at the rear end. The problem was sorted by removing the 4" bung by the drivers seat, put your hand inside the tunnel and follow the fuel pipe until you meet a spring clip with an open top so the pipe lifts out.
The new pipe is more rigid and the one clip keeps it well away from the prop
Tony

Re: Fuel Line Routing

PostPosted: Thu May 12, 2022 9:29 pm
by 111Robin
10kph wrote:I have replaced my nylon pipe with a modern chemical resistant 8mm plastic tube and all is fine. I had a bright idea of pulling the old tube out as the new one was attatched th the other end on an original Lotus chassis.
My irst problem was that the original pipe seemed to be stuck and just stretched without moving at the rear end. The problem was sorted by removing the 4" bung by the drivers seat, put your hand inside the tunnel and follow the fuel pipe until you meet a spring clip with an open top so the pipe lifts out.
The new pipe is more rigid and the one clip keeps it well away from the prop
Tony

Thanks, I didn't think of gaining access this way, I'll have a look to see if I can see where it should be clipped.

Re: Fuel Line Routing

PostPosted: Sat May 14, 2022 5:44 pm
by Donels
I don’t see a problem running it inside the car. I did consider this myself but stuck with the existing route inside the tunnel. If you use cunifer it should be fine. If you’re concerned about it being damaged in an accident then you have much bigger things to worry about than the fuel pipe.

Re: Fuel Line Routing

PostPosted: Sun May 15, 2022 8:06 pm
by billwill
Vegantune of Finchley replaced my fuel line in the tunnel with an electric pump in the boot and braided fuel pipe inside the right-hand cavity wall of the cabin of my S3 Coupe. But though no leaks could be found there was always a smell of fuel in the cabin.

Eventually I got fed up with that and replaced the braided rubber pipe with a Kunifer hard pipe It was difficult getting it behind the reinforcing frame of the door as it involved carefully bending & rebending the pipe to fit it in, but I eventually managed it and the in-cabin smell vanished.

More details and photo in my long refurb topic starting at: viewtopic.php?t=26101&f=19&start=90#p178305