Building your own fuel rail

sidy · Post by **sidy** » Sun Jul 16, 2006 2:59 pm

G'Day all,

I am looking for some guidance from the group on this questions.. Is
it realistic to construct my own fuel rails (for 4 cyclinder
motorcycles) from soldered coper tubing or is it better to buy an
aftermarket assembly?

Sid Young

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"Classic Japanese Motorcycle Restoration Site"
http://z900.piczo.com/
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jakobsladderz · Post by **jakobsladderz** » Sun Jul 16, 2006 5:01 pm

I would avoid lead solder (tends to fatigue) but bronze or silver solder should be OK. That said, I have a friend who used copper tubing for water pipes on his turbo and they fatigued and broke (after only a couple of months use so unlikely to be corrosion related) resulting in a blown engine (failure occured on racetrack and the vital sign changes were missed). If this were fuel rail, there would have been fuel spraying everywhere.
I guess I'm saying that steel tubing may be a better bet to avoid the chance of fatigue cracks and subsequent fuel leakage.

Duncan

PSIG · Post by **PSIG** » Sun Jul 16, 2006 5:34 pm

There are many brass, copper and steel soldered and brazed factory setups out there - mostly steel. The difference is that they are fully supported so the tubing does not get stressed and work-hardened by vibration. Generally copper is avoided for this reason, although I have seen racing setups using it in short supported T sections. They were bright (nickel or chrome) plated for corrosion resistance.

Steel tubing can be had in a nearly perfect I.D. for injectors and be brazed as many factory rails are. I have scavenged injector cups from brazed OEM rails like this. Once again the brazing is fatigue prone so support it - and the brazing itself makes the steel more brittle over time to a limited degree. This is why aircraft manufacturers no longer assemble steel fuselage sections with brazing.

It's a balance of your skills and your wallet.

David

mitsuko · Post by **mitsuko** » Mon Jul 17, 2006 1:12 am

My first fuel rail was made of brass bungs , copper tube and silver solder .
It's been used for abt a year , then I changed it for an extruded aluminium one .
Not because it failed or leaked , but because it didn't look nice .
There must be some pictures of it in the succes stories .

As long as it's decently secured to the engine block , there's no problem .

Pat

Post by **jsmcortina** » Mon Jul 17, 2006 5:29 am

Mine are sections of steel tube brazed together. However the aluminium extrusions will be easier to work with and look prettier afterwards.

James

TT350chevelle · Post by **TT350chevelle** » Mon Jul 17, 2006 9:24 am

Square steel tubing, 1/2 compression fittings and braze 380.Easy,clean and cheap.Heres the only pic I have of my fuel rails.
http://public.fotki.com/tt350chevelle/6 ... 10002.html

Brad J.

sidy · Post by **sidy** » Mon Jul 17, 2006 11:20 pm

Aluminium... Now thats a good thought!

I can anodise it red so it looks fast also ;)

Sid

PS - Hadn't thought of Aluminium, real asy to work with and easy to
get and to machine any unique fittings...Thanks James

On 7/17/06, jsmcortina <jsm@jsm-net.demon.co.uk> wrote:
>
>
>
> Mine are sections of steel tube brazed together. However the aluminium
> extrusions will be easier to work with and look prettier afterwards.
>
> James
>
>
> ________________________________
>
> My Success story http://www.msefi.com/viewtopic.php?t=8008
> MS1/Extra at: http://megasquirt.sourceforge.net/extra
>
>
> This post is at:
> http://www.msefi.com/viewtopic.php?p=130963#130963
>
>

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Visit Sid's
"Classic Japanese Motorcycle Restoration Site"
http://z900.piczo.com/
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Bow · Post by **Bow** » Tue Jul 18, 2006 9:55 am

You might want to check this out:
http://sdsefi.com/techrail.htm

garrymc · Post by **garrymc** » Tue Jul 18, 2006 7:52 pm

TT350chevelle wrote:Square steel tubing, 1/2 compression fittings and braze 380.Easy,clean and cheap.Heres the only pic I have of my fuel rails.
http://public.fotki.com/tt350chevelle/6 ... 10002.html

Brad J.

What is 'braze 380' ?

TT350chevelle · Post by **TT350chevelle** » Wed Jul 19, 2006 8:42 am

garrymc wrote:
TT350chevelle wrote:Square steel tubing, 1/2 compression fittings and braze 380.Easy,clean and cheap.Heres the only pic I have of my fuel rails.
http://public.fotki.com/tt350chevelle/6 ... 10002.html

Brad J.
What is 'braze 380' ?

Here's the link to Braze 380 pdf file.
http://www.lucasmilhaupt.com/assets/bra ... /BR380.pdf

and another link with info on a number of brazing products.
http://www.lucasmilhaupt.com/htmdocs/br ... _free.html

Brad J.

PSIG · Post by **PSIG** » Wed Jul 19, 2006 2:23 pm

I use a similar brazing rod from Lincoln you can get at Home Cheapot for about $4 plus some dip-flux. I prefer to add the dip-flux for better coverage. Mine are usually steel-steel.

turbo54 · Post by **turbo54** » Thu Jul 20, 2006 12:20 pm

Is there some advantage to brazing rather than welding? I've made many a fuel rail and I've always welded it.... had never even thought to braze.

Am I missing something or is brazing just a cheaper method (don't need a TIG machine)?

mitsuko · Post by **mitsuko** » Thu Jul 20, 2006 1:37 pm

Brazing has the advantage that the solder or what's it called flows .
And it can be applied with little heat compared to welding , wich reduces
warpage . Also , it doesn't take to much skill to braze or solder .

Mag welding does takes some skill to get it all leak free .

An acetylene/oxygene welding torch offers the advantage
of the metal flowing continuusly , like a bazing process , but
introduces to much heat to the rail .

A tig is kinda best of both worlds . Nicely controlled melt , not to much heat , argon protection . Now that I own a tig , I wouldn't even consider brazing or acetylene welding anymore .

Pat

PSIG · Post by **PSIG** » Thu Jul 20, 2006 3:20 pm

A big plus for low-budget DIY MSers is that brazed factory-style rails can be made with just a $30 MAPP torch kit, rods and simple tools. A whole fuel rail could be made for under $50 including the equipment!

David