fuel line size/pump size for 600 hp, 10.50 et car?

[cgarb]

In my opinion the 2 holley blue pumps were more than enough for that on methanol, except for the seals crapping out because they weren't designed for that fuel. Also, the holley blue pump of then and the blue pump of today were two different beasts. The real problem in his set up was the one regulator. If he would have ran two, I would see nothing wrong with that set up at that speed.

[bigjoe1]

Back in 1973, I ran one Holey blue pump into one Holley regulator to feed my 850 HP BB Chevy--- NO PROBLEMS AT ALL




JOE SHERMAN RACING

[cgarb]

On gasoline Joe?

[bigjoe1]

YES SIR !




JOE SHERMAN RACING

[vortecpro]

Back in 1973, I ran one Holey blue pump into one Holley regulator to feed my 850 HP BB Chevy--- NO PROBLEMS AT ALL




JOE SHERMAN RACING

Yes you did, but there was also two carbs.

[bigjoe1]

So very true-- Twice the number of needle and seats



JOE SHERMAN RACING

[andyf]

Back in 1973, I ran one Holey blue pump into one Holley regulator to feed my 850 HP BB Chevy--- NO PROBLEMS AT ALL




JOE SHERMAN RACING

But, but Joe, didn't you know that you needed a Big Mutha Super Zonker 2500 gph fuel pump?

[cjperformance]

Back in 1973, I ran one Holey blue pump into one Holley regulator to feed my 850 HP BB Chevy--- NO PROBLEMS AT ALL




JOE SHERMAN RACING

Yes you did, but there was also two carbs.

!! Caught , or does this just prove 2 carbs are better than one

[bigjoe1]

Back in those days, the tunnel ram was 70 HP better than the best single 4 barrel on a serious engine.




JOE SHERMAN RACING

[cgarb]

I'm not doubting this works because obviously it has been done but, you said there is twice the number of needle and seats. 2 carbs so 4 needle and seats but there is still only one regulator. The size of the ball in a Holley blue regulator is only like 3/16" or something. How can that flow enough fuel through that to feed 4 needle and seats? I would think that regulator had that system pinched pretty bad. This pertains to my Alky fuel system with the throttle bypass. That's why I got rid of my regulators, The needle and seat was close to the same size as the Regulator ball, .150 vs .187 so I was thinking If I dumped the regulator and was able to get full flow to the needle and seat that would have to be better right? But after all that my EGT's still are higher than they should be. Methanol 1360 EGT at 1/4 mile traps. It seems almost unresponsive to jet changes. I can go up 10 front and back and it only changes it like 40 deg lower but then it acts rich, uses a lot of fuel per pass and will hardly gain water temp. At first I thought it was a fuel delivery issue and that's what prompted the changes but now I'm thinking its maybe my EGT gauge...

[MadBill]

Back in 1973, I ran one Holey blue pump into one Holley regulator to feed my 850 HP BB Chevy--- NO PROBLEMS AT ALL




JOE SHERMAN RACING

But, but Joe, didn't you know that you needed a Big Mutha Super Zonker 2500 gph fuel pump?

I mentioned this in another topic, but it bears repeating: There's such a thing as too much pump capacity. A friend races an 800+ hp Corvette in the SCCA Trans Am road race series and at Sebring his first race with the car, he ran into fuel starvation issues at a little over 45 min. into the one hour race. After stumbling to the finish, he checked the fuel cell and found it still held ~ 5 gallons. He did a flow test to check for obstructions and calculated the system could flow about 250 GPH, enough to feed over 3,000 hp.
The problem was that the return line flowed into the opposite corner of the tank and with such a huge bypass volume, the flow back to the pick up area was so restricted by the cell foam that it was gulping air. The fix was a pump with less than half the capacity.

PS: Having two pairs of N&Ss doesn't affect the system flow requirements; it's the power that does, so a 2 x 4 set up, if it made 70 hp more, would only need an additional 6 GPH.

[cjperformance]

I'm not doubting this works because obviously it has been done but, you said there is twice the number of needle and seats. 2 carbs so 4 needle and seats but there is still only one regulator. The size of the ball in a Holley blue regulator is only like 3/16" or something. How can that flow enough fuel through that to feed 4 needle and seats? I would think that regulator had that system pinched pretty bad. This pertains to my Alky fuel system with the throttle bypass. That's why I got rid of my regulators, The needle and seat was close to the same size as the Regulator ball, .150 vs .187 so I was thinking If I dumped the regulator and was able to get full flow to the needle and seat that would have to be better right? But after all that my EGT's still are higher than they should be. Methanol 1360 EGT at 1/4 mile traps. It seems almost unresponsive to jet changes. I can go up 10 front and back and it only changes it like 40 deg lower but then it acts rich, uses a lot of fuel per pass and will hardly gain water temp. At first I thought it was a fuel delivery issue and that's what prompted the changes but now I'm thinking its maybe my EGT gauge...

Holley blue reg has 0.217" hole and the ball can unseat far enough to see full flow potential, so a possible 0.037sq" area.
A 125 n/s has 0.0123sq" area but never sees close to that in running condition due to the needle taper sticking up into the seat hole.
Not ideal and yes pushing the freindship but it can and does work.

[cjperformance]

As Bill said the extra n/s' s dont change fuel required,,, the extra pair of n/s still flow the same total volume v's hp, to do this each n/s therefore does not need to open as far (less float drop to cope with demand) so fuel level and quality in the bowl (airation) are improved.

[mag2555]

Pump pressure need wise no one seems to be factoring in that drag car accelerating above 2g ( quite easy for a sub 11 second car!) will back out .3 psi of fuel pressure for every ft of fuel line after the pump.

[cjperformance]

Pump pressure need wise no one seems to be factoring in that drag car accelerating above 2g ( quite easy for a sub 11 second car!) will back out .3 psi of fuel pressure for every ft of fuel line after the pump.

For what diameter line?
Even still in my example there was probably around 12' of 3/8"line between pump and reg, even if this killed 3.6psi of potential pressure at max accel the holley blue that could(claimed) achieve 14 psi had plenty of reserve. But this is interesting and a data log running off of a flow meter in a bypassing reg application would tell an interesting tale im sure!