grazzledazzle
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| posted on 22/2/09 at 06:01 PM |
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Fuel rail options
Looking at re-spacing some bodies. Given the pressures involved, lack of machining tools etc, i was wondering if anyone knows of any easy fittings for
the injectors which can then be connected by rubber fuel pipe? I was thinking a push fit T onto the injector or something similar?
Any other suggestions / offers to make me two fuel rails appreciated!
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BenB
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| posted on 22/2/09 at 06:08 PM |
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You can use 15mm plumbing T pieces.
Most injectors fit nicely (ie snuggly) inside these, and you can use yorkshire (solder ring) pipework. You can also get 15-8mm reducers and then have
8mm hose barbs at the end which will take normal rubber fuel hose.
It's like it was meant to be 
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grazzledazzle
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| posted on 22/2/09 at 06:35 PM |
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Ben,
Do the injectors simply plug into the t piece ie held in with nothing more than the o ring? Also how does the hose barb fit to the 8mm section?
Sorry, feeling a bit thick today.
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BenB
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| posted on 23/2/09 at 02:47 PM |
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Yes, the injectors are a snug fit inside the T-piece (there may be a little piece of the 15mm tube inside, can't remember the exact detail). You
don't need clips like on most OEM rails. OBviously you need to hold the fuel rail in place to stop it blowing off (quite easy to make a rail
stay with DIY equipment).
I'm going to use some of these
15mm rubber lined pipe clamp with 10mm threaded boss.
You use a 8mm is used in some plumbing installations so you just need a 15-8mm reducer, then a short piece of 8mm copper pipe. 8mm pipe is also used
for propane in caravans so you can get a 8mm pipe to 8mm hose barb (compression fitting).
I'll probably be making my fuel rail in the next few weeks so I'll post some pictures near the time...
In the meantime have a butchers at
http://82.44.126.36:76/Inject.htm
which is someone's MG Midget fuel rail using copper pipe....
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flak monkey
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| posted on 23/2/09 at 03:54 PM |
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It does depend what injectors you have. Std bosch style injectors are suiatble for 15mm hose. GSXR and many other bike ones need a 10.8mm hole which
means you need to drill your own rail.
David
Sera
http://www.motosera.com
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grazzledazzle
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| posted on 23/2/09 at 04:27 PM |
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Cheers chaps, I like your locost style.
High capacity fuel rail though! Will do some measuring, I'm amazed the injectors fit into a 15mm pipe without anything restraining them i.e a
bellmouth but i guess it is the O ring which makes the seal, the fuel rail just needs securing relative to the injector.
Piece of piss!
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grazzledazzle
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| posted on 23/2/09 at 07:19 PM |
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Having a bit more of a think....
My old tb's used to get too hot to touch on the zetec.... if the fuel rail gets hot is it not going to melt the solder resulting in kaboom?
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paulf
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| posted on 23/2/09 at 09:33 PM |
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If you have a fuel return from the rail it should keep cool, if it was hot enough to melt solder then the fuel would be vaporised and engine wouldnt
run.
As said if running bike injectors copper pipe is to large and you will need 10.8 mm bore fitings.
Ive made a couple of fuel rails from 10mm bore steel tube with 10.8 bore steel bosses silver soldered on using a jig.
Paul.
quote:
Originally posted by grazzledazzle
Having a bit more of a think....
My old tb's used to get too hot to touch on the zetec.... if the fuel rail gets hot is it not going to melt the solder resulting in kaboom?
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BenB
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| posted on 23/2/09 at 10:34 PM |
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I've been digging 
Looks like most car injectors have 14mm o-rings which means you probably fit a short piece of copper pipe inside the T-piece. Apparantly it's a
tight squeeze...
I wouldn't worry about the solder coming unstuck, you have to get it pretty damn hot to melt. I suspect it doesn't get much hotter than
the hot water coming out of my (soldered) hot water supply to the taps.... and if it is getting that hot you really need to something about it. The
fuel will vapourise and cause problems long before the fuel rail pops....
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Jenko
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| posted on 24/2/09 at 08:49 AM |
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quote:
Originally posted by grazzledazzle
Having a bit more of a think....
My old tb's used to get too hot to touch on the zetec.... if the fuel rail gets hot is it not going to melt the solder resulting in kaboom?
The latest unleaded Solder melts at around 220 degrees....If it gets hot enough ot melt that, then you have 'deeper fish to fry' :-)
Although, the inlet side of the engine should not really get that warm...Do you know why this happens??.
Paul.
MY BLOG - http://westfieldv8.blogspot.co.uk/
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corpi
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| posted on 24/2/09 at 11:01 AM |
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I have doubts about soldering joints in the HP fuel system.
Because of the injectors opening and closing suddenly there will pressure pulses.
I'm afraid these pulses will cause the soldered joints to "creep" and eventually leak.
Similar prusure spikes hapen in household water pipes, and they can, if strong, and frequent enough, cause the soldered joints to come apart. (seen it
happen)
While the pulses might not be as strong, in a fuel system, the frequancy and duration is much higher.
Has anyone actually used soldered fuel rails, in an running car for 10's thousand miles? and checked the joints?
maybe i'm just paranoid, but it seems sensible to be paranoid arround High Pressure fuel...
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grazzledazzle
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| posted on 25/2/09 at 11:29 AM |
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Now i'm utterly confused.
A bit of research on the web has some people saying you will end in a ball of fire using copper fuel rails, while others seem to think it's
fine. Then i have found many others who swear that aluminium should not be used for a fuel rail either.... so what are we left with? Steel?
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grazzledazzle
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| posted on 26/2/09 at 05:20 PM |
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Anybody tried these chaps?
Looks like they make some good kit.
http://www.extrudabody.biz/servlet/the-Fuel-Delivery/Categories
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flak monkey
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| posted on 26/2/09 at 05:30 PM |
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quote:
Originally posted by grazzledazzle
Now i'm utterly confused.
A bit of research on the web has some people saying you will end in a ball of fire using copper fuel rails, while others seem to think it's
fine. Then i have found many others who swear that aluminium should not be used for a fuel rail either.... so what are we left with? Steel?
Well most modern cars use a combination of aluminium and plastic, usually jointed with o-rings.
If its good enough for a 200,000mile tintop its good enough for my GTS.
I bought some aluminium extrusion from Ross Machine Racing
http://www.rossmachineracing.com/
Cheaper than buying it over here, and you get enough to make 2 rails.
Just cut to length, drill correct sized holes for injectors, round off the ends of the holes to prevent o-ring damage and drill and tap the ends
1/4BSP and you are away.
David
Sera
http://www.motosera.com
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MikeR
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| posted on 26/2/09 at 06:43 PM |
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Mate used to do car fuel systems for a living before he decided to marry a girl and move to Brunei.
Copper is bad for fuel systems due to the copper leaching something into the fuel. This deposit builds up on the injectors over time and clogs them.
Not too much an issue on carbs as the holes are larger. As this is a known fact in the industry and therefore they don't use copper - he
couldn't tell me if it happens in 1000 miles or 100,000. Based on lots of other people using copper i think its more likely to be a lot more
than 1000.
Having said that, he threw a fit and got me some proper metal (no idea what) pipe covered with plastic for my fuel lines. Its teh same stuff as used
in the BMW mini. Being honest, i'll probably use copper as its far easier
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