What are the pros and cons of mechanical vs electric fuel pumps on a 66 with a 289 putting out about 200 RWHP? Would an electric increase my performance and/or fuel economy? Is an electric pump hard to install? Thanks for the feedback.
An electric fuel pump will require a switched 12 volt circuit, a relay, a regulator, a fuel return line and a fuel tank with a sump (if not using an in-tank pump). Carburators only require 7-9 lbs of fuel pressure, but electric pumps typically put out much more than that. Therefore you will need to regulate the pressure down to a usable number. Also, the fuel that will be ''refused' by the regulator needs to be re-routed back to the fuel tank via a return line. On a carb'd engine that is not terribly ''Hi-performance'' a mechanical pump is just easier. As long as the engine cranks you have fuel. A good one is rebuildable and will still cost you under $100. Plus you wont need to add a regulator or the other mentioned parts that are subject to failure over time. That is my opinion on the matter.
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97 Cobra-03 Cobra t56 and alum DS, SPEC111 clutch, FRPP 4:10,T&J Performance Forged 4v(8.9:1), Manley rods, Novi 2000 w/ Fast Track A/A I/C, Barry Grant Fuel syst., BBK longtubes and H-pipe, MSD ignition, Detroit True Track, Magnaflows, 315 NT01's on 17 x 11's, KB BAS, SCT tune and about a million other things. 575 RWHP. Going into the shop this winter, looking for 650 RWHP.
you can get in-line electric fuel pumps which put out the needed 7 lbs of pressure without a regulator. The con is that it is another electrical connection that you will have to run. Can't really think of any pro's that would make me want to put one on my car. I guess it is just a personal choice.
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1966 Mustang Coupe. Mica Merlot with black stripes, Deluxe interior, 302 4V, 4-speed toploader, 3:70 9" rear end.
Thanks for the feedback. Sounds like it can get complicated. I guess one pro is that you could rig a cutoff switch as an anti-theft deterrent - but there are other simplier ways to do that. The reason I ask at all is that I have been looking at front end setups from Vintage Air and Billet Specialties that both require an electronic fuel pump due to the placement of the brackets. Thanks again
As already stated, you can get an electric pump that needs no regulator and if you buy the right pump you won't need a return line to the tank, relays, etc. An electric pump is an added complication that I have not installed on my Mustangs. I have added one to another car I own and that took a single wire and the pump I installed - nothing else. Not on my Mustang, but for that other car I find that the gas is more volatile than 30-40 years ago and my mechanical fuel pump sucking from the engine end was always vapor locking. With an electric pump at the rear pushing gas forward that vapor lock problem disappeared.
Another advantage is if your car sits for a few days all the gas will evaporate from the carb. With an electric pump you can re-fill the carb by waiting a few seconds. Otherwise you have to crank the engine for quite a while for the mechanical pump to refill the carb so it will start. Less engine grinding to start is always a good thing.
Additional economy from an electric pump? I don't see how that could ever happen. And if you are only talking 200 HP I doubt there is any mechanical pump that couldn't supply more than enough gas to the engine so I really doubt there would be any performance advantage.
As previously stated mechanical pumps are just easier. Plus on summit they sell performance ones to feed even higher performance motors. The only real need to switch to an electric pump would be if it was in the way or if you had a motor so over the top that you needed a whole lot more fuel. Otherwise its just more trouble than its worth. Plus carbs were made to run on mechanical fuel pumps without sumps in the tank. Thats what the carb bowls are for so you don't get cutouts when there is a break in fuel delivery. Once fuel injection came into play the higher performing electric fuel pumps were needed
I installed an electric pump on my 67. It is quite a complicated installation if it's done right with the necessary safety features that should be included with the pump. Oil pressure safety switch, inertia switch and relay circuits. A lot of work. Most electric pumps make enough noise to drive you nuts. This is the main reason that I went back to a high volume mechanical pump.
The noise is the thing I've heard again and again - course the Flowmasters would drown out some of that. I'm leaning towards sticking with a high volume mechanical pump and leaving well-enough alone. Thanks for all the feedback - this is a great forum!
The noise is the thing I've heard again and again - course the Flowmasters would drown out some of that. I'm leaning towards sticking with a high volume mechanical pump and leaving well-enough alone. Thanks for all the feedback - this is a great forum!
Oh yeah, noise is something I forgot to mention. I have long tubes, x-pipe, and Magnaflows with no cats and if you stand behind my car the pump is every bit as loud as the exhaust.
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97 Cobra-03 Cobra t56 and alum DS, SPEC111 clutch, FRPP 4:10,T&J Performance Forged 4v(8.9:1), Manley rods, Novi 2000 w/ Fast Track A/A I/C, Barry Grant Fuel syst., BBK longtubes and H-pipe, MSD ignition, Detroit True Track, Magnaflows, 315 NT01's on 17 x 11's, KB BAS, SCT tune and about a million other things. 575 RWHP. Going into the shop this winter, looking for 650 RWHP.
The reason I ask at all is that I have been looking at front end setups from Vintage Air and Billet Specialties that both require an electronic fuel pump due to the placement of the brackets. Thanks again
What are you looking at doing ?
.. really surprised that any of it would require removing the stock fuel pump ....
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Motor's in !
AOD is all (most) hooked up !
Wiring is all done (except alternator, starter, battery wires and grounds)
Interior is 80% back together
If i'm correct, the 5.0 crate engines sold by Ford do not have the eccentric on the crank(?) that is there on old 302's specifically to activate the mechanical pump. That's the reason I have an electric one on my '67 with a crate 302. It required no return line, no special "sump" gas tank, just the wiring. It is loud, like others have mentioned.
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1969 Boss 302 (Vintage Race Car) Calypso Coral
2002 Saleen SC281 True Blue
1967 Coupe, 5-speed, Grabber Orange
.. really surprised that any of it would require removing the stock fuel pump ....
The stock PS pump bracket is sort of L-shaped to avoid the problem with the mechanical FP but the aftermarket brackets on Vintage, March and Billet Spec all interfer and thus need an electronic system. I have since decided to just dress up the v-pulleys with some billets from March so a mechanical FP is no problem and the way I plan to go.
Mechanical Vs. Electric Fuel Pump 
. I'm leaning towards sticking with a high volume mechanical pump and leaving well-enough alone. Thanks for all the feedback - this is a great forum!
