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mo balls than $cents$
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Discussion Starter #1
how many gph does it take to feed 2 dominators? putting them on a bds 8-71 ontop of a 9 to 1 540 . does anyone make a mechanical fuel pump that'll get the job done without a regulator?
 

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superdave on these boards, he sells Clay Smith mech pumps, good guy price, you what the 1/2" high pressure pump. If you get it, take it apart and remove the inner spring. Yhat will lower the pressure enough that you don't need a reg. This is the pump EVERY SINGLE blown GN circle boat is useing except with the inner spring and a reg. If it can't keep up, you will have to put the spring back in and get a reg.



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steelcomp was here
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Basically .5 lbs fuel/hp/hr . Gas is 6lbs per gallon. 1000hp= 500lbs/hr/6=83.3gph. That's a basic requirement, at the engine. Take into consideration all the dynamcs of the fuel system, and at what pressure you can deliver that amount of fuel. Basically double it is what I usually do.
 

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steelcomp was here
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superdave on these boards, he sells Clay Smith mech pumps, good guy price, you what the 1/2" high pressure pump. If you get it, take it apart and remove the inner spring. Yhat will lower the pressure enough that you don't need a reg. This is the pump EVERY SINGLE blown GN circle boat is useing except with the inner spring and a reg. If it can't keep up, you will have to put the spring back in and get a reg.
Why go to all that work, and not just run a reg. and be done with it. Jeezzzz...some guys just gotta make things difficult!:D
 

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mo balls than $cents$
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Discussion Starter #6
actually MR. Steel, I personally run 2 regs. One on each carb with a balance line between. He just asked for a recomment with out a reg and I thru in my two cents. On the other hand, you had to go and hit the poor guy with advanced calculis. PS how ya been, keeping busy?
:D you guys think this 1 will get r done?

http://store.summitracing.com/partdetail.asp?autofilter=1&part=HLY-12-454-20&N=700+4294925239+4294839053+400178+4294891547+4294908216+4294840133+115&autoview=sku

says shut off pressure is at 8-9psi
 

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mo balls than $cents$
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Discussion Starter #8
thanx for the advise! :)devil order that holley p# thru my local autozone:p and got it for 113.95, no shipping :D be here tommorrow mornin
 

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mo balls than $cents$
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Discussion Starter #10
let me know how it works out, thinking of one those for another deal I am putting together Thanx
will do, he's got a dash mounted fuel pressure gauge and we're gonna try to run it without a regulator at all. i can't see that pump pushing pressure past 4 hi volume needles and seats, but shit happens:)st carb kits won't be here till next wed , so it'll be the weekend after this 1 before we get the boat wet.if it works out fine, we're tearing it all back apart and putting nitrous plates under the dominators :)devil putting a electric pump/seperate tank on that system;)
 

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mo balls than $cents$
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Discussion Starter #13

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you may not understand exactly what that chart is saying, but the main thing is that you do not want any restriction in the fuel system either in or out, fuel lines size and filter flow are very important. -10 inlet minimum, -8 oulet, minimum. Basically the chart says that if you are crui9zing along at 4000 and your gauge reads 6psi, the most the pump is moving is about 10-15 gph. When you stab it and the motor gets to 6500 and the gauge reads 4psi you are moving 150gph. Like Steel said, you need about 85 gph for a 1000hp, that leaves you with about 65 gph cushion. That pump will be just fine. We run about 5psi thru .110 and have zero problems



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Yeh, as we all know, or should know, free flow means dogschit. We need the fuel pump 'dyno' (as I call it) graphs. It will help make a better decision since a little more real world vs marketing BS.

That said, any electric fuel pump company worth a poop will also have such graphs. In fact, they tend to be a little more detailed and include more data.

Volts vs psi along with showing amperage draw and fuel volume output.

Here's a Walbro chart:
 

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steelcomp was here
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26,512 Posts
actually MR. Steel, I personally run 2 regs. One on each carb with a balance line between. He just asked for a recomment with out a reg and I thru in my two cents. On the other hand, you had to go and hit the poor guy with advanced calculis. PS how ya been, keeping busy?
:D LOL..yes, too busy.
 

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mo balls than $cents$
Joined
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11,734 Posts
Discussion Starter #17
Yeh, as we all know, or should know, free flow means dogschit. We need the fuel pump 'dyno' (as I call it) graphs. It will help make a better decision since a little more real world vs marketing BS.

That said, any electric fuel pump company worth a poop will also have such graphs. In fact, they tend to be a little more detailed and include more data.

Volts vs psi along with showing amperage draw and fuel volume output.

Here's a Walbro chart:
i learned something new today :)devil i'll be looking a for a chart from now on ;) thanx for the info
 

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21' Daytona
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FYI, I am running that exact pump on my BBF. 521, dual Dom's flowing 1120each, 8-71 10% under at the time (now 8 over), no regulator, -8 from each tank to filter/seperator, -8 from seperator to fuel pump, -8 pump to distribution block, -6 to each carb. A tick under 8lbs at idle, and a tick above 6 at WOT.

No troubles last year at all, and I did some long flat out runs..........
 
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