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Fuel line size?
laptoprob - 13/3/12 at 09:32 PM

I`m about to install a new Redtop engine which hopefully be pushing 250 bhp+.

Its running on Alpha 45 TB`s.

What size fuel ine should i have?

Is it more important to have larger lines on carbs due to low pressure than it is under a high pressure system?

Ive currently got 6mm on the 230 bhp setup with no issues whatsoever(same tb`s).

Whats your thoughts?

daniel mason - 13/3/12 at 09:44 PM

my f20c install is running 8mm id fuel lines

snapper - 14/3/12 at 09:50 AM

8 to 10mm
Flow is different to pressure, you can have high pressure and low flow,
What CC's per min/hr are your injectors?
Should e ableto work out required flow based on that.

laptoprob - 14/3/12 at 10:59 AM

quote:
Originally posted by snapper
8 to 10mm
Flow is different to pressure, you can have high pressure and low flow,
What CC's per min/hr are your injectors?
Should e ableto work out required flow based on that.


Hi Snapper,

Im pretty good with flow and pressure theory being a hydraulic component reseller.

My query was for the pipe size really, just wondered what size people were running on a similar setup etc.

I have LET injectors fitted now which flow 304cc/min.

Think i may have to bin these off and change to SAAB red at 340cc/min.

8mm sounds right to me unless anyone else has other ideas?

tomgregory2000 - 14/3/12 at 11:06 AM

on my sr20det install i was running 8mm id hose and had no lack of fuel and that was for 321bhp

edit: i was running 760cc injectors and a bosch 044 fuel pump

[Edited on 14/3/12 by tomgregory2000]

omega 24 v6 - 14/3/12 at 12:38 PM

I run 10mm on my redtop. The only stipulation for using that is it was free. 8mm should be fine.

atspeed racing - 14/3/12 at 01:42 PM

we have supplied over 600bhp on 8mm fuel lines.

- colin.

britishtrident - 14/3/12 at 04:33 PM

With LPG conversions which have no pump and demand a flow-rate than petrol the change over point from 6mm to 8mm pipe is reckoned to be 180hp but a lot of LPG conversions are producing well over 200 hp on 6mm pipe. 250 hp on petrol with an hp pump and regulator at the engine end should be OK.

laptoprob - 14/3/12 at 05:17 PM

quote:
Originally posted by britishtrident
With LPG conversions which have no pump and demand a flow-rate than petrol the change over point from 6mm to 8mm pipe is reckoned to be 180hp but a lot of LPG conversions are producing well over 200 hp on 6mm pipe. 250 hp on petrol with an hp pump and regulator at the engine end should be OK.


I thought this myself but quote a few people say 8mm is the way forward.

Thanks for the info.

laptoprob - 14/3/12 at 05:19 PM

quote:
Originally posted by atspeed racing
we have supplied over 600bhp on 8mm fuel lines.

- colin.


Suddenly 6mm seems fine

britishtrident - 14/3/12 at 05:33 PM

A high pressure pump can overcome the increased pressure drop due to fluid friction in the pipe, as long as the pressure at the delivery end is enough to maintain the regulated output pressure.

laptoprob - 14/3/12 at 06:02 PM

quote:
Originally posted by britishtrident
A high pressure pump can overcome the increased pressure drop due to fluid friction in the pipe, as long as the pressure at the delivery end is enough to maintain the regulated output pressure.


Couldnt have put it better myself