Mechanical Vs. Electric Fuel Pumps

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Jan 24, 2005 | 04:37 PM

JMoney454

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From: Southern California

Mechanical Vs. Electric Fuel Pumps

I'm going to be replacing my fuel pump, and I was wondering if there was any real advantage to using an electric pump instead of the mechanical one. Any thoughts?

Jan 24, 2005 | 05:37 PM

AlwaysWave

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From: Hoosier

Cruise-In III Veteran

unless you need more than 6-9 lbs pressure, there's no need for the hassle of installing an electric pump.

Jan 24, 2005 | 06:44 PM

Tom73

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From: NM

Quote:

Originally Posted by JMoney454

I'm going to be replacing my fuel pump, and I was wondering if there was any real advantage to using an electric pump instead of the mechanical one. Any thoughts?

No advantage on a stock engine.

tom...

Jan 24, 2005 | 06:59 PM

Gordonm

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From: Forked River NJ

Quote:

Originally Posted by AlwaysWave

unless you need more than 6-9 lbs pressure, there's no need for the hassle of installing an electric pump.

These have worked fine for millions of miles. Unless you are pushing a ton of HP stick with mechanical. Even then it is marginal for a street car.

Jan 24, 2005 | 09:23 PM

C3 Stroker

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From: Youngstown Ohio

Quote:

Originally Posted by JMoney454

I'm going to be replacing my fuel pump, and I was wondering if there was any real advantage to using an electric pump instead of the mechanical one. Any thoughts?

470 HP...383 cu. in....11.8 ET.......mechanical fuel pump, no problems. (170 GPH, Carter HP )

Jan 24, 2005 | 09:28 PM

C3 Stroker

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From: Youngstown Ohio

Quote:

Originally Posted by JMoney454

I'm going to be replacing my fuel pump, and I was wondering if there was any real advantage to using an electric pump instead of the mechanical one. Any thoughts?

470 HP...383 cu. in.....11.8 ET.........mechanical fuel pump, no problems. (170 GPH, Carter HP, no regulator necessary)

Jan 24, 2005 | 10:58 PM

Ironcross

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From: Taylor Michigan

With all of the above answers. All the high horsepower GM and Vette engines were equiped with a mechanical pump. 283/327/350`s from 283 to 375HP carb and FI SB engines and L88, ZL1, L71, 427`s plus LS6 and LS7 454`s. The exceptions are those engines with out a fuel pump boss, which are most late model crate engines. Actually there are more. But these are the high horsepower engines and all use a stock pump with 3/8 fuel lines.

Jan 24, 2005 | 11:03 PM

comp

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From: eville in

cooler fuel to the carb. is a plus there is some HP loss with a mech. pump (not much i know)

Last edited by comp; Jan 27, 2005 at 08:44 AM.

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Jan 24, 2005 | 11:05 PM

comp

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From: eville in

cooler fuel to the carb. is a plus there is some HP loss with a mech. pump (not much i know)

Jan 25, 2005 | 04:09 AM

#10

Turbo-Jet

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From: Vancouver BC, Canada

As a theft deterrent, you can easily install a secret switch to disconnect power to an electric pump. peace of mind is worth something too

Jan 25, 2005 | 06:43 PM

#11

comp

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From: eville in

Quote:

Originally Posted by Turbo-Jet

As a theft deterrent, you can easily install a secret switch to disconnect power to an electric pump. peace of mind is worth something too

true a small plus

Jan 25, 2005 | 06:57 PM

#12

Mike Ward

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Quote:

Originally Posted by comp

there is some HP loss with a mech. pump (not much i know)

This advantage is more than completely offset by the extra load put on the alternator which must produce the electricity to run the pump. No free lunch here.

Jan 25, 2005 | 07:04 PM

#13

isosceles

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From: Deltona (son of Deland and DAYTONA) FL

Quote:

Originally Posted by Mike Ward

This advantage is more than completely offset by the extra load put on the alternator which must produce the electricity to run the pump. No free lunch here.

My Holley Blue only draws 3 amps. That can't produce much drag. But neither can moving a pushrod .375". I agree, must be a wash.

If I took the time to verify I hadn't damaged that end of the cam with a bent fuel pump pushrod, I might not have recently switched. I liked the idea of consistant fuel pressure.

The installation of the electric pump was a little time consuming though.

Jan 25, 2005 | 07:45 PM

#14

Marks69BB

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From: NC USA

I think my electric helps on startups since as soon as you turn the key, you have fuel pressure. My BB vette starts almost instantly like a modern car with FI.

Jan 25, 2005 | 07:57 PM

#15

Twin_Turbo

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and if you wire your fuel pum w/ an oil pressure cut off switch it could save your engine also in case something goes wrong.

Jan 25, 2005 | 07:58 PM

#16

oregonsharkman

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From: Keizer Oregon

edelbrock aluminum mechanical pump----------383 stroker/440hp----runs perfect!!!!

Jan 26, 2005 | 10:29 PM

#17

68/70Vette

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From: Redondo Beach, California

Quote:

Originally Posted by JMoney454

I'm going to be replacing my fuel pump, and I was wondering if there was any real advantage to using an electric pump instead of the mechanical one. Any thoughts?

I don't know for sure, but I've always been suspicious about how good mechanical pumps work at high engine rpm. At 5000 rpm, the mechanical pump piston is working at 2500 pulses per minute. That's 41 pump pulses per second! I just wonder if the fuel starts to cavitate. With my mechanical pumps, I think I've experienced high rpm power drops at high power (full throttle in fourth gear). Just to get rid of this possible fuel starvation problem, I've decided to install an electric pump.

Jan 26, 2005 | 11:07 PM

#18

greyghost79

Burning Brakes

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From: San Antonio Texas

if mechanicals are so good (and i'm very happy with mine), why are they putting electrics on just about all cars built today?

Jan 26, 2005 | 11:32 PM

#19

68/70Vette

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From: Redondo Beach, California

All the engines today are fuel injected and they need high fuel pressures for the injectors. I think this is why they use all electric today. The electric fuel pumps for today's engines produce much more pressure than the electric pumps designed for carbs. (This is my belief based upon reading fuel pump vendor descriptions.)