Mech Fuel Pump Drag Racing 318

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72DMag

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Does anyone have any recommendations for a mechanical fuel pump to use on a 318 for drag racing? Engine is a standard bore, stock stroke, 10:1 318 with 302 heads and a 650 demon carb. Cam is comp cams 268 grind flat hyd tappet. Car is going to have 4.56 gears.

Would like to have a fuel pump that does not require a fuel regulator like the discontinued Carter M6902 fuel pump.
 
Mancini Racing lists the Carter pump you want but an Edelbrock Part Number 1720 will handle up to 600hp and doesn't require a regulator.
 
What's your budget? Not tryin to be smart, but you're not gonna find something for fifty bucks.
 
I am running the Carter high flow fuel pump and that will show a short coming in round robins (back to back) runs with the vehicle slowing down a tad. This is on a street driver, not a race car. Two different fuel needs and requirements. Both can do a good job in feeding enough fuel but one is simply better at it and does it consistently.

REALLY! In a drag car, if you MUST run a mechanical pump, that’s one thing, but if you don’t have to, run an electric pump. Now everyone can cry there to much money, there more complex, and cry about having to run a regulator and return line. Fine, make all the excuses you want but an electric pump with a regulator and return line is what you should be doing at a minimum!

How complex after that basic set up you go is on you.

The bottom line in drag racing is ether consistency or flat out speed. Both are achieved best by a electric fuel pump. There consistent on keeping the fuel there, more reliable bowl fueling and making more power. That’s just the bottom line, sorry.
 
RustyRatRod said:
I would certainly try one. I think without a return it would be enough. Might be enough with one, never know till you try it.
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There does come a time, but his stock block 318 with 302 heads, 625 carb and his cam isn't the time of demand. Certainly nothing wrong with upgrading it, but at his build he won't "need" it. I've had more motor and used the stock fuel pump with factory 5/16 fuel line without issue. Many times in fact.
 
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318willrun said:
There does come a time, but his stock block 318 with 302 heads, 625 carb and his cam isn't the time of demand. Certainly nothing wrong with upgrading it, but at his build he won't "need" it. I've had more motor and used the stock fuel pump with factory 5/16 fuel line without issue. Many times in fact.
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The gear was my only concern. Couple that with a return and it could run into trouble with a stock pump.
 
Should clarify few things. By drag racing the car I mean street/sportsman class. It's not a tight competition class. I'm possibly thinking about exhaust mufflers and drive car around in the future so mechanical pump is alot quieter than electric. I think I'll try stock pump and just see how she does and go from there. The car was upgraded to 8an fuel line and iirc that is 1/2".
 
72DMag, Just a thought. How about a booster pump on a switch.
Holley makes a Mighty Mite pump in 1.5-4 psi,4-7 psi and 7-10 psi.
I have been using these for years on street/strip cars. I have the 1.5-4 psi on my 63 (318) now using the mechanical pump and switching on the electric when necessary. For a test I removed the mechanical pump to see if the Might Mite (1.5-4 psi)would run a 360 4bbl Thermo Quad Cordoba on the street and it did the job.Wide open passes not a problem.
Holley, Mr.Gasket, K&N all have them,they are rebranded same pump. Only about $50.
Again Just a thought. Oh one more thing. When the engine is running you can't hear them running.
 
Right on @Darter6. I use one of the mighty mite style “click clack” pumps in line with the stock mechanical fuel pump. It’s worth about a half pound of extra fuel pressure at idle and and a little over a pound at 4,000 rpm. I’ve got it hardwired into a switch on the dash. You only have to run it when you think you need it. You’ll have plenty of fuel flow for your deal.
 
72DMag said:
Should clarify few things. By drag racing the car I mean street/sportsman class. It's not a tight competition class. I'm possibly thinking about exhaust mufflers and drive car around in the future so mechanical pump is alot quieter than electric. I think I'll try stock pump and just see how she does and go from there. The car was upgraded to 8an fuel line and iirc that is 1/2".
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If you can hear your electric fuel pump with the engine running....
1. You need MORE motor
2. You need louder mufflers
3. You need a better stereo
I endorse option 1.
 
MRGTX said:
How much power does a stock mechanical pump support? When do you start to run into trouble?
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See engine masters mechanical fuel pump test......
All I know is that I ran a sumped stock tank, a 1/2" line, and a Carter hi pressure, high volume mechanical pump on a 500hp 440. When I changed to a fuel cell, and a 150gph Paxton electric pump and regulator..... the car picked up more than a half second.
 
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Think abut this. Lets do a little math. Now this is obviously not exact you get the point.
Say your engine went from 1,000 RPMs instantly to 6,000 RPMs. Now how long will it take you to go 1/4" mile ? Let's say its a slug and takes 15 seconds. OK ?
6,000 RPMs ( Revolutions Per Minute) Divided by 30 seconds = 3,000 RPMs. Divide again by 2 . 15 seconds = 1,500 RPMs . 4 times 15 seconds = 1 minute.
That is how many revolutions your engine would technically turn in 15 seconds. For 1500 rpms Times your engines volume, how much fuel would you need ?
What is the GPM of your fuel pump ?
 
How do you guys plumb, and wire your Mighty Mite pumps in with your stock mech pumps,???. Do you plumb it into the main fuel line in series,??.

Thanks
Dave
 
barracudadave67 said:
How do you guys plumb, and wire your Mighty Mite pumps in with your stock mech pumps,???. Do you plumb it into the main fuel line in series,??.

Thanks
Dave
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If they are it’s almost defeating it’s purpose. Cause the stock pump would be sucking through it. Don’t forget all the hp motors from Chrysler came with a mechanical pump. Even the mighty Max Wedge and the Hemi which had 2 4 barrels. 440-6 and 340-6 had 3 carbs. Kim
 
Here’s the things with mechanical fuel pumps.
They loose efficiency when they heat up. Adding a return line to the system is a very good idea. Mechanical or not.

Putting an electric pump before the mechanical pump is ensuring the mechanical pump always has fuel. The mechanical pump regulates the fuel amount and psi.

Should the electric pump fail, the mechanical pump will draw fuel through the failed electric pump at a lower rate than it would itself.

Sirelan67 posted a stock pump.
Not worthy for drag racing.

The previously mention Carter HP or race pump is OK for HP street machines. I run them on the regular. But they are not up to task for serious track efforts on a consistent basis. The Holley mechanical fuel pump is better, but still suffers from heat.

Ether way, a mechanical fuel pump will need to be cooled down between drag runs for best & peak operation.

To be honest here, plumbing in a regulator is easy. Running a return line when it’s not equipped on the car from the factory is a PIA. But it is worth the effort.
 
rumblefish360 said:
Putting an electric pump before the mechanical pump is ensuring the mechanical pump always has fuel. The mechanical pump regulates the fuel amount and psi.
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Agree. Adding a booster pump at the rear of the car as close to the fuel tank as possible.
 
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