Fuel pump size ?

[wedge5]

I am running a Mallory 140 pump but I am wondering if it is big enough. I looked at my fuel pressure gauge at the end of one of my runs and it was reading 4psi. I have it set at 6 1/2 now
I have around 650hp

 

[ykf7b0]

I think it's big enough but I would set the initial pressure at 7 1/2.

 

[snakeoil24]

where do you have the fuel pick up located?

 

[Endangered Species]

The mallory 140 is a good pump. I agree with YKF and maybe bump your pressure up to at least 7lbs and let her rip. If you pressure is between 4-5 lbs going through the traps I would say your good.

 

[Budnicks]

How many carb's is it feeding ??, I'm assuming a single 4bbl... what kind of fuel pressure regulator are you using a bypass style ??, or a regular type dead headed style ??, the bypass style, with a return line back to the tank are better, for keeping a constant flow of fuel at a constant pressure setting, keeps fuel cooler & the pump from over heating also supposedly... what size fuel lines are you running ??, what size & style of pick-up &/or sending unit ??... Also AN#6/or 3/8" at a minimum I hope, AN#8/or 1/2" is better, AN#10/ or 5/8" for multiple carbs... a 140gpm should feed a single 4bbl 600hp carburetor engine fine... with the adequate size fuel lines, the proper fuel pressure, proper style needle & seats, proper float levels & adequate fuel pressure regulator settings &/or style...

 

[67 B-body]

I'm using a 140 gph pump, and I think our setups are pretty close.... I've had two fail on me "rotary vein" so far, but I think there was a good reason for one of the failures. The first pump burnt up the winding's, and I found a piece of trash that got through and into the pump. This was before I had a filter on the fuel cell outlet / before the pump. The second sprung a leak past the O-Ring on the rotor shaft.
I don't think I have any starvation issues with 140 gph though...

 

[wedge5]

Dual carbs
1/2 line from cell to reg. then teed to 3/8 to each carb.
Deadhead style
I am going to turn up the pressure to see if that helps. It sounds like I have the pressure set a little low.

 

[Endangered Species]

I didn't know you were running two carbs, If it were me, I would have prefered 2 - 140 pumps, actually that's what we're running.
However if you're running the single pump @ 6.5 lbs. and it's only dropping to 4 lbs going through the traps... I would go ahead and bump the pressure up to 7 lbs and let it eat!

I had a calculator that figured required GPM. If I can find it I'll post it.

 

[383man]

I agree I would turn it up a tad to 7 psi and try it. I was running just the Holley red pump thats like 97 GPH and I use a stock gas tank with a 3/8 sending unit and line. I use a single 850 DP and I think the red pump is set about 6 psi as it has no external reg. Its a street car so I dont have a fuel gauge to see my fuel press in the traps. But in my 3700 lb 63 it has run 10.70's at almost 125 with just the red pump. I have now upgraded to the Firecore 140 pump with an external reg I set to 6.5 but have not made it back to the track. You are feeding two carbs but with a larger fuel pump. It cant hurt any to turn it up to 7 and give it a try. Good luck , Ron