Fuel systems for drag cars

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Illahe

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Hello All,

I am currently working out the bugs on my 84 Daytona. It is small block powered and has a tube chassis with 32/14.50's. The chassis has a small fuel cell in the engine compartment and the area is limiting the installation of an electric fuel pump. My 1/8 mile shake down didn't illuminate any issues, yet when we took it out to the 1/4 the car was bucking for fuel. The system has a mechanical pump with 6an and I estimate the engine is producing 375 hp at altitude.
there is a carter fuel pump on the way, but I am concerned that it will not be sufficient for a 414 ci small block that is awaiting its place in the engine bay. Any information on setting up an adequate fuel system with or without fuel return is appreciated. The new power plant will be running dual Holley's.
 
Illahe said:
Hello All,

I am currently working out the bugs on my 84 Daytona. It is small block powered and has a tube chassis with 32/14.50's. The chassis has a small fuel cell in the engine compartment and the area is limiting the installation of an electric fuel pump. My 1/8 mile shake down didn't illuminate any issues, yet when we took it out to the 1/4 the car was bucking for fuel. The system has a mechanical pump with 6an and I estimate the engine is producing 375 hp at altitude.
there is a carter fuel pump on the way, but I am concerned that it will not be sufficient for a 414 ci small block that is awaiting its place in the engine bay. Any information on setting up an adequate fuel system with or without fuel return is appreciated. The new power plant will be running dual Holley's.
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I've seen the bucking happen from too much pressure. You're going to need to get creative, mount the fuel pump further away from the cell if you have too for the bigger engine.
I wish I had that car, do you have any photos?
 
MOPARMAGA said:
I've seen the bucking happen from too much pressure. You're going to need to get creative, mount the fuel pump further away from the cell if you have too for the bigger engine.
I wish I had that car, do you have any photos?
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You've got a good point about finding a alternate location for the fuel pump. I'll post some up some photos later.
 
If I had that car even without seeing pictures everything but maybe the fuel cell would get ripped out. Should have at least 8 coming out of the cell to an electric pump, to a regulator, then split lines to I’m guessing a Holley carb. Some of those 6an fittings are necked down so small I wouldn’t want them on my lawn tractor.
 
pittsburghracer said:
If I had that car even without seeing pictures everything but maybe the fuel cell would get ripped out. Should have at least 8 coming out of the cell to an electric pump, to a regulator, then split lines to I’m guessing a Holley carb. Some of those 6an fittings are necked down so small I wouldn’t want them on my lawn tractor.
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That's what I wanted to know. Thank you for your input.
 
They Carter has work fine for use even @450 to 500Hp
AN 6 works for us BUT beware cheap Chinese restrictive AN stuff as
they are the Kiss of Death for fuel delivery!
 
I tend to overbuild a hair so I’m ready for the next batch of speed upgrades. It’s cheaper to do it once.
 
We ran a Dakota in Stock Eliminator and Crate Motor classes. Our fuel cell was mounted in the bed of the truck. I wouldn't want a fuel cell mounted under the hood because if you front crash the car, chances are the cell will rupture. The fireball will be horrendous and think of where all of the fuel will be. As PBR said, #8 feed and #6 as return, and also as mentioned be careful of the chinesium crap that is out there. Only use quality fittings and line.
 
I can only tell you what I have done.
Fuel cell. Block one eight outlet, a ten to the filter, ten to the pump, eight to 1/2 aluminum line to the regulator. Two Eights out of the regulator to the carb on the nine second car, sixes for the eleven second car. 250gph pump on the nine, 150gph on the eleven second car. A mallory gerotor, and a Paxton vane. (I LOVE the mallory, but its REDICULOUSLY expensive now, since holley bought mallory. Holley wants to sell HOLLEY pumps)
Both probably would have been better with a return setup, but both ran fine dead-headed.
 
Demonracer said:
We ran a Dakota in Stock Eliminator and Crate Motor classes. Our fuel cell was mounted in the bed of the truck. I wouldn't want a fuel cell mounted under the hood because if you front crash the car, chances are the cell will rupture. The fireball will be horrendous and think of where all of the fuel will be. As PBR said, #8 feed and #6 as return, and also as mentioned be careful of the chinesium crap that is out there. Only use quality fittings and line.
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A 2nd on the quality line. I have replaced countless (it seems) braided rubber lines that deteriorate and leak.when I do, now, I always use teflon line. More expensive for sure, but it lasts MUCH longer, and doesn't leak!
Don't be like me, do it right the first time..... for the 414.
(Three -6 teflon lines for my Opel 454, fittings on both ends, special made by a plumbing company, cause I didn't have the tools for the teflon, total of about four feet, $140)
 
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33IMP said:
I can only tell you what I have done.
Fuel cell. Block one eight outlet, a ten to the filter, ten to the pump, eight to 1/2 aluminum line to the regulator. Two Eights out of the regulator to the carb on the nine second car, sixes for the eleven second car. 250gph pump on the nine, 150gph on the eleven second car. A mallory gerotor, and a Paxton vane. (I LOVE the mallory, but its REDICULOUSLY expensive now, since holley bought mallory. Holley wants to sell HOLLEY pumps)
Both probably would have been better with a return setup, but both ran fine dead-headed.
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Thank you.
 
No return line for me. Number 10 from my BG400 pump to the regulator up front. And two number 8 feed the carb. But then again I’m on alcohol. I guess I shouldn’t say no return line as mine has a return on the pump in back.
 
I'm just imagining how inexpensive a fuel system could be when you only have go a few feet a couple time's.
I think I spent close to $2000.00 on my pump, filters, regulator, ptfe lines and fittings.
@pittsburghracer , one of the summit codes from you lol
 
Quality fuel systems are a must have item if you cheap out on it, it will come back to bite you at the most inopportune time. Ask me how I know!
 
My 250 mallory cost me $50, reman, at a supershops warehouse sale. (If that tells you how old it is. I think the original supershops closed in the nineties).
I try to use hard line as much as I can. My aluminum lines haven't ever leaked, last 30 years, and probably cost a tenth of what the same length of braided line would be.
I think I had $300 in the nine second cars fuel system. I bet it would cost $1500 to duplicate it today. (The mallory pump is over $600 now).
 
I do not run a return line unless the car runs deep in the nines or faster.
Never found anything on our Stockers or Superstockers.
 
I run a return system on ANYTHING (regardless of hp) that is street driven, or has an electric pump.
 
A lot of people run a return but Dont know how to run a return. To properly run a return to the tank the fuel has to enter above the fuel level and be expelled under the fuel level so you don’t put air into the fuel. Fuel systems don’t like bubbles. Most guys just dump the fuel on top of the fuel in the tank or cell.
 
pittsburghracer said:
A lot of people run a return but Dont know how to run a return. To properly run a return to the tank the fuel has to enter above the fuel level and be expelled under the fuel level so you don’t put air into the fuel. Fuel systems don’t like bubbles. Most guys just dump the fuel on top of the fuel in the tank or cell.
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Not true. I tested that. In a 3 gallon cell.

Every railbird that saw it told me how stupid I was.

So I spent an assload of money to put the fuel in below fuel level. It did zero.

Unless the tank is almost out of fuel it won’t make any difference.

And that was with MFI, which sends more fuel to the tank as rpm goes up. With an electric pump it returns less fuel as rpm (and power) goes up.
 
Newbomb Turk said:
Not true. I tested that. In a 3 gallon cell.

Every railbird that saw it told me how stupid I was.

So I spent an assload of money to put the fuel in below fuel level. It did zero.

Unless the tank is almost out of fuel it won’t make any difference.

And that was with MFI, which sends more fuel to the tank as rpm goes up. With an electric pump it returns less fuel as rpm (and power) goes up.
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Believe what you want. I probably have less than 20.00 in mine. I took a bulkhead fitting and drilled and tapped it for a compression fitting and used a piece of stainless tubing. Sorry I Dont have a better picture but my one computer crashed years ago. Adding fuel every round is usually the only thing I do on race day, but I do it every round.

IMG_4335.jpeg
 
Men aren’t the best at reading instructions but when we do we sometimes learn something. Not sure if this helps or no but I buy BG400 pumps for pennies on the dollar because they have issues with them. I grab them and rebuild them. Lol

IMG_4336.jpeg
 
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