Fuel Pipe Size

[Steve Faithful]

Can Any one advise as to the best Diameter
copper fuel pipe to use between the tank and fuel pump,
I have a Chevy 350 and am using the original
mechanical fuel pump and holly-600 carb

thanks
Steve

[Stefan]

Steve,

I've used 1/2" from the tank to my electric fuel pump, and the 3/8" from there
onwards. You've got a long unpressurised run so I would stick to 1/2" or greater...

[wilf]

3/8" should be ok. Remember that there are some drawbacks to going to too large a size - on heavy acceleration the fuel in the pipe will try to stay where it is whilst the car accelerates- so the more fuel you have in that pipe(i.e. the greater the pipe dia), the greater it's inertia, greater chance of the pump running out of "suck" and the carb leaning out just when you don't want it - on full bore.

Wilf

[dave]

Yup. 3/8",it's all i've ever used with any engine with no problems.

Stefan. 1/2"? what are you running man?A 500ci Keith Black on Nitro Methane

From Dave...A founder member of the Mechanical Fuel Pump Appreciation Society.
and the "3/8",one size fits all" club,2nd dan.

[VinceGledhill]

I'm running a rover V8 and have bought some 10mm (outsided diamiter) copper mocrobore central heating pipe to use as a fuel line.

Will this be OK?

Regards
Vince@gledhill.info

[callum]

Perfic - and for other builders availabe from Screwfix Tel 0500 414141 part no 7717 @ £13.19 for 25 metres!

[chris m]

Interesting. I would always have assumed that fuel pipe and CH pipeing were different, especially as fuel pipe has to put up with more vibration than the average house piping!

Out of interest presumably you got the brake piping from the local motor factors?

[TonyD]

Vince,

Snap.......wickes is the cheapest I think.

As regards brake pipes dont bother buying a flaring kit etc. I got mine professionally made up while I waited by local factors, complete car £23.00 incl the dreaded VAT.

Btw be ready when buying bits to make lots of promises to your suppliers re taking them out for a burn once the thing is finished....I had to agree to two burn ups today.....one for the scrappy guy and one for the propshaft guy....its an excellent way of getting extra discount !!

Cheers,

Tony..........Still knitting himself a loom.................

[callum]

Pure copper (e.g. Automec) from varous factors is better than cunifer (i.e. copper/iron mix) which work hardens faster and needs better tools to flare well. It is also more corrosion resistant but slightly pricier. The microbore is fine for fuel if you are running it aong chassis rails supported by rubberised P clips and with flexible hoses to tank, fuel pumps, filters, carbs etc. There should be no appreciable vibration proplem and the copper is as malleable as the brake lines so fit for similar duty but at much lower pressures as the wall is proportionately thinner.

[VinceGledhill]

The Yorkshireman has finally done you there dangerous...

Brake pipes (from wholesale car parts warehouse in Bradford... Maxess) 3.50+VAT for a roll.

Borrowed Steve from the northern cobra club's flairing tool... Ends again from maxess... less than about 6 quid all up. Including the splitters and bleed screws.

Did have to get some more ends though from the local car parts guy because my front calipers are metric and the rear are imperial.

So now I know I will have an imperial metric car...hehehe... and it's rolling now. Wheels on... and engine in place. Just got to get some new mounts now...

Regards
Vince@gledhill.info