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MG MGB GT V8 Factory Originals Technical - Fuel flow requirements of bigger Rover V8s?
|How much fuel flow would a warmed-over Rover 4.6 take? I don't mean pressure -- I figured out a long time ago that my Carter likes 5psi -- I'm talking flow. 70gph? 120gph?|
Also, has anyone found it beneficial to re-plumb the system with 3/8" fuel lines? I am thinking that the MGB's 5/16" lines are not fat enough to allow good flow to the V8.
|70 gph would equate to 5 miles per gallon at 140MPH, should be OK.|
|A worst-case scenario would be to believe that your Carter can deliver 600 CFM and at 17 : 1 air/fuel ratio would yield 35 cubic feet; about 5 gallons U.S. per minute or 300 gallons per hour.|
|Before someone else corrects my math: 35 cubic feet is about 2100 lbs., nearly 300 gallons, so 18,000 gallons per hour. Sounds improbable, so air/fuel mixture must be per weight rather than volume?|
|George, wow. At that rate I'd empty the gas tank in two minutes!!!!!!|
|The usual rule of thumb, for carbureted engines, is: if using a deadhead (i.e. non-return style) regulator, fuel flow in GPH = 0.43*HP, and if using a return-style regulator (theoretically the best way to do it by far, but a major PITA to implement), 0.27*HP (HP using flywheel figures). At least those are the formulas that are used in the racing fraternity. |
What my circle-track racing friends seem to like to do is to use a big, high-flow fuel pump with a return system, to always keep plenty of cool fuel circulating, always there if you need it. Big, high-flow fuel pump + deadhead-style regulator is a recipe for an overheated, noisy, short-lived fuel pump. Plus dead head regulator springs bounce when the fuel is backed up and you suddenly mash the pedal to the floor, and so you can get a lag ... so to ensure smooth transition, they say to use the return system.
One of these days when I have a spare 20 hours I'll go for it ....!
|Peter Burgess calculates it thus -|
Max HP x 0.6 / 7.5
So if your 4.6 produces 250 bhp, it needs a pump capable of producing 20 gallons per hour (UK gallons)
So one producing 30 gph would give a good margin for any deterioation in performance of the pump over time.
This thread was discussed between 24/01/2001 and 25/01/2001
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