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roverman
Art Gertz
Winchester, CA.
(3188 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

How much Fuel ?
Posted by: roverman
Date: April 08, 2010 08:35PM

SBC, boat, approx. 550hp, gas, 4bbl. 1,200 ft. elev. "Carb Shop", is saying a 200 gph. mech fuel pump is neccessary. Biggest "Carter" is 172 ? How much is enough ? Max power should be no "fatter" than 12.8/1 afr. ? Thanks, roverman.


ex-tyke
Graham Creswick
Chatham, Ontario, Canada
(1165 posts)

Registered:
10/25/2007 11:17AM

Main British Car:
1976 MGB Ford 302

authors avatar
Re: How much Fuel ?
Posted by: ex-tyke
Date: April 08, 2010 09:51PM

Per the "Tech Tips from the Professor" article in a typical Summit Racing catalogue, his fuel pump sizing method is based on the following:
At WOT, an engine requires 1/2lb fuel per hr per HP and 1gal gas =6lb.
So, for a 550HP engine,
fuel pump gph=550x1/2lb/hr
=275lb/hr
=275/6gph
=46gph
Based on this method, your carb shop recommendation seems high but you might want to have an independent look at this logic.

Math correction made...must have been that last beer.



Edited 1 time(s). Last edit at 04/09/2010 12:28PM by ex-tyke.


hoffbug
Tony Hoffer
Minnesota
(323 posts)

Registered:
10/15/2007 05:25PM

Main British Car:
Olds 215 EFI

Re: How much Fuel ?
Posted by: hoffbug
Date: April 08, 2010 10:05PM

The old standby is ... Hp x 0.23 + GPH

Use more if using a bypass style regulator or planning on drag racing.


alana
alan atkinson
10567
(232 posts)

Registered:
06/19/2008 08:06PM

Main British Car:
68 TR250 LS2

authors avatar
Re: How much Fuel ?
Posted by: alana
Date: April 08, 2010 10:05PM

You sure they didn't say a 200lb/hr pump?
Take a look at something like this - which is plenty for a 550hp carb'd engine:

[aeromotiveinc.com]

Look at the flow charts.
A 200 gallon pump would be 1200lbs/hour!


hoffbug
Tony Hoffer
Minnesota
(323 posts)

Registered:
10/15/2007 05:25PM

Main British Car:
Olds 215 EFI

Re: How much Fuel ?
Posted by: hoffbug
Date: April 08, 2010 10:36PM

I was thinking something like this..
[aeromotiveinc.com]
With a deadheaded regulator.
[aeromotiveinc.com]


roverman
Art Gertz
Winchester, CA.
(3188 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: How much Fuel ?
Posted by: roverman
Date: April 09, 2010 11:15AM

Thanks all. I'm thinkin, they we're thinkin, Donald will be makin more like 500 hp, of which 200 lbs/hr. would be right there. Graham, when I do the math, 550 hp. X .5,(1/2), I get 275 ? Tony, HP X .23 + GPH. ? I don't know the GPH. How do I add an un-known ? Thanks for the refresher. roverman.



Edited 3 time(s). Last edit at 04/09/2010 11:39AM by roverman.


ex-tyke
Graham Creswick
Chatham, Ontario, Canada
(1165 posts)

Registered:
10/25/2007 11:17AM

Main British Car:
1976 MGB Ford 302

authors avatar
Re: How much Fuel ?
Posted by: ex-tyke
Date: April 09, 2010 12:32PM

Art,
Damn, you caught me with a math error...sheepishly corrected above.



hoffbug
Tony Hoffer
Minnesota
(323 posts)

Registered:
10/15/2007 05:25PM

Main British Car:
Olds 215 EFI

Re: How much Fuel ?
Posted by: hoffbug
Date: April 09, 2010 06:53PM

Sorry Its been a long week.. formula should read
HP x 0.23 = GPH


roverman
Art Gertz
Winchester, CA.
(3188 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: How much Fuel ?
Posted by: roverman
Date: April 10, 2010 08:35PM

Ok, with "Graham's" formula, 45.8 gph/550 hp. "Tony's" formula, 126.5 gph./550 hp. Anybody else want to dable in the mistyque ? roverman.


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