What fuel pump you guys using for your modded engines? Electric or mechanical?

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4mm

Well-known member
Joined
Aug 26, 2012
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Location
S. TX
My Car
1971 Mustang 351C 4V Fastback
I'm down to the last decision I need to make before I start ordering parts and maxing out the credit card I took out specifically for parts lol.

I have a stock 71 Boss with headers. Going with a blue thunder intake and demon 750 annular carb. I'm boxing away the correct original parts meant for trailer queen driving :-/ and trying to mildly increase performance.

My main concern is fuel boiling. I live in one of the hottest cities in the U.S. and we all know these engines tend to run hot. I already have a 1/2 wood spacer ready for the composite carb. Do mechanical fuel pumps tend to boil fuel easier than electrics?

I'm trying to keep a stock look appearance and the only decent mechanical pump I can find is the one by RobbMc. Anybody using one?

http://www.robbmcperformance.com/products/ford550.html

http://www.robbmcperformance.com/products.html

I am also considering a Holley electric fuel pump, the gerotor style for quietness.

 
I am running a stock replacement mechanical fuel pump on my 408 Cleveland with almost 600HP with no issues. I am also running an 850 or 950 quick fuel carb. Feeds it just fine.

 
I'm using electric. I initially started out with a Holley "Black" rotary vane fuel pump, but it was LOUD! (You can hear the loud 'buzzing' noise just before it starts - never goes away, and resonates through the entire car inside)



Here's the old Holley pump (I had run the plumbing a bit different to make sure it didn't hit anything, by using a 90 degree elbow... but never got a pic:

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Here's the new Holley solenoid style pump - fits even better and is QUIET!

11000308_1050382174972700_8431350656838990094_o.jpg


This is the rock guard/cover I made for it using a piece of an undercarriage panel from a Jetta (or something) someone left at the Auto Hobby Shop after changing their oil... never came back for it after 6 months, so I figured it was fair game. ;) :D

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Hope this helps.

And no, tragically I haven't gotten around to cleaning all the overspray and bondo-dust off the undercarriage yet. :shy:

 
Fuel under pressure takes a lot higher temperature to vaporize (vapor lock). As long as the fuel line from the tank to the mechanical pump isn't near or in contact with anything hot, and as long as the sock in the tank is clean (fuel under vacuum/suction vaporizes at a lower temperature) the mechanical pump should be fine. Vapor lock generally takes place between the tank and the engine mounted pump. An electric pump mounted near the fuel tank will pretty much eliminate any possibility of vapor lock.

I am concerned about the wood spacer for the carburetor (unless you are talking about the laminated one from Edelbrock), wood absorbs fuel, and contracts and expands with humidity changes, making it difficult to maintain proper torque on the mounting studs/nuts. You can get a phenolic or plastic spacer for insulation.

 
Yes it the Edelbrock laminated spacer.

 
I have the RobbMC pump on my Boss. I tried the Holly electric first. Changed mounting positions 2 or 3 times. At that time the RobbMC was on backorder for 7 or 8 months. They had lost their supplier of the arms they used in the Ford pumps. Their pump ended all my problems.

The problem with the Holly electric was the car would run out of gas at about 2 miles. Of course, this always happened when I was on it. If i ran it on low rpm's around town it would run fine. Take off out of town with any mount of rpm's, it would run for about 2 miles and die. Very frustrating until I figured out that it was just running out of fuel. Wait 4 minutes and it would start.

Will sell the electric Holly for $50.00. It has about 18 miles on it. Looks like new.

Wade

 
I use before a new Holley (blue)with regulator, DON'T buy this pump it makes a LOT of noise.

If you want to use a electric pump take a Mallory, but why a electric pump... all Mustang runs great (+40) years with mechanical pumps.

 
Looks like I'm going with the RobbMC. Are you using hardline to the pump or flex hose? What size?

 
Looks like I'm going with the RobbMC. Are you using hardline to the pump or flex hose? What size?
I'm using hard line, with the factory breaks and flex hoses, plus an extra length missing for the fuel pump (where you see it in the pics above). From the point where it re-enters the engine compartment, I've gone with flex hose to the fuel pressure regulator, on the end of a hard line assembly running into the carb. The whole under-hood set-up will be out the window soon, when the Edelbrock E-Street fuel-injection goes in.

Don't forget to use Fuel Injection rated fuel line where you need the flex hose.

 
Eric, I'm seriously starting to reconsider EFI. After adding in all the costs of good quality parts for the fuel system and carb, the total price starts to add up and isn't too far off from a complete EFI kit. Why are you going with the Edelbrock? I was looking into the Holley Terminator.

Also what intake will you be using?

 
Eric, I'm seriously starting to reconsider EFI. After adding in all the costs of good quality parts for the fuel system and carb, the total price starts to add up and isn't too far off from a complete EFI kit. Why are you going with the Edelbrock? I was looking into the Holley Terminator.

Also what intake will you be using?
I'm not changing anything except the throttle body itself, and adding the rest of the required components - I purposely built the car to eventually have the fuel injection (planned on saving up for it once I got the car "done." Then the wife decided the Holley Black fuel pump was too loud and asked if that "fuel injection thingie I was talking about" came with a new, quiet fuel pump. Of course it does... ;) "Then go order it," were her next words. Yes ma'am. :D

I currently have an Edelbrock Performer 351C-2V intake with an Edelbrock 1406 Performer carb. I went with Edelbrock for the obvious reason (I have always preferred Edelbrock to Holley, Demon, etc.,) but also because the system ECM has Bluetooth and a provided HP Slate 7 for set-up & tuning purposes. That means I can put the ECM anywhere I like and not have to "plug anything in" to make changes, diagnose, or monitor the system, etc.

The only things I should have to do is basically swap out the carb for the Edelbrock TBI unit, install an O2 sensor in the exhaust, run the harness to the ECM, re-plumb the underhood fuel lines to include a high-pressure pump/1 gallon reservoir, and fire it up. The TBI unit is roughly the same size as their Performer carbs, with roughly the same layout (throttle linkage, fuel inlet, electrical connections, in pretty much the same locations, etc.). Should pretty much be a drop-in affair.

I ain't gonna lie - it's not cheap. The "returnless" system I got was more expensive than a "return" system, mostly because I needed the high-pressure pump/reservoir unit. Add a "lift pump" (I got two, one for a spare) and I'm scrapin' $2800.

But here's the deal: when the Ram Air air cleaner is on, nobody has to know a thing. Mine's a restomod, but I've been trying to keep all of my 'modern' mods as stealthy as possible, with the 'period correct' mods in the spotlight. I want the reliability, functionality, and forget-ability of the fuel injection, but I still want the 'old school muscle car' appearance.

Holley make fine products - a LOT of people swear by them. I don't think you'll be unhappy with the Holley unit... or whatever system you decide to go with. My affection for Edelbrock goes back to my '78 K5 Blazer - it came with a Performer 1406, and I had no problems making friends with it. A few years later, a friend wanted a new carb (his Holley was leaking from everywhere), and I recommended an Edelbrock Performer - he swapped on the new Edelbrock, and the car ran like a champ out of the box. It's still running great to this day, almost 15 years later with no leaks... there's literally nothing to leak from except the top-cover gasket and worn-out butterfly/throttle pivots in the body (just like with MC2100s - which I have on my Jeep). Every Holley I've encountered was a leak monster, and when it was replaced with an Edelbrock, things got drastically better for the owner.

Again, just personal preference.

 
Eric,

My dads buddy used the same kit you mentioned on his 71 but used the return line style. He said he used the hardline that runs from the charcoal canister to the fuel tank as his return line and took a lot of the expense and labor out of running a new return line. I was considering this when I get around to saving up $3000 for my EFI.

 
That's a great idea and was even recommended... but I had no canister with mine (just the bracket), and the return line was mangled - so I never ordered a new one. I've installed all new hard lines (brakes and fuel) from Inline Tube, so I actually have "factory-style" fuel lines from the tank to where the mechanical pump used to be (which I also deleted and used a block-off plate).

Once I figured out I was going to need the HP pump/reservoir, I considered installing a new return line... but without the lift at the Auto Hobby Shop, I'm WAY less enthusiastic (I guess I was spoiled). ;)

 
I hear ya about the lift. I helped my buddy install one in his garage and I sure do visit his garage a lot more than I used to!!! Make you lazy in a hurry!!! But it does help with those pain in the butt jobs where you would normally be laying on your back.

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Good article - but even knowing this, I still would've gone with Edelbrock... just a personal preference. ;) :D

 
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