Electric fuel pump vs Mechanical

[Mrturner1]

Guys

I'm wondering about the differences and +\-'s of electric fuel pumps vs mechanical ones. My C10 has a mechanical, and I assume it works fine because my truck ran good before the recent tear down. I've had a few newer hot rods (trans am and mustang) and they had electric fuel pumps but they were fuel injected as well.

My current build is a 9 to 1 SBC, ProComp 170cc heads, Comp 280H cam, Edelbrock 650 AVS carb, Long tubes and flowmasters, HEI, and Edelbrock Performer RPM manifold.

Would I benefit from an electric fuel pump? The truck is driven on weekends when I feel the need to burn a little rubber, purely a for fun truck so wiring up switches or whatever I need is totally fine with me. Budget isn't an issue on this one, and I DO plan on moving the fuel tank out from behind the seat and relocating under the bed where spare tire goes. If I'm leaving out some info just ask

Thank you guys
Matt

[davepl]

I'd never run an electric fuel pump unless I had to (ie: EFI, or if the block doesn't have a boss like the old ZZ502s I've got). I don't think there's any benefit to an electric except as an anti-theft or maybe to prevent vapor lock, but the mechanical pumps on these are so simple and work so well why mess with it?

[Gromit]

Been meaning to ask this and here is my chance; thank MTurner and hopefully the answer will help with the OP too.

Do all SBC mechanical fuel pumps (Carter, Edelbrock, Holley, GM) have the quirk or design flaw that if the rubber fuel pump diaphragm sprongs a leak it fills your crankcase with gasoline?

Because a rubber diaphragm in a $25 pump that flexes every second crank revolution seems to me to be a pretty failure-prone part to bet an entire engine on...

When I first learned of it I thought: Really? A GM Mechanical Engineer actually allowed this through their quality control process? It just seems beyond belief.. Couldn't they just have sealed off the crankcase from the fuel section of the pump?

I guess that while you are driving you are just supposed to watch your oil pressure gauge and temp gauge and hope that you notice in time if that diaphragm fails?

[cdowns]

if you use an unreliable electric poc you get to know the tow truck guy on a very reglular basis

[72_K10_Vegas]

I used the electric. I have the 383 stroker / roller and as I am living in Vegas, well you know. Sitting at a stop light in August.

BTW its an Aeromotive 340 with regulator and AN-8 return. Very good flow and keeps bowl full even when in negative G's accelerating, towing or 4x4 up a steep hill. Also located in the tank designed and built by Boyd.

IMO its a good system when hooked to the Holly 670. I have not dialed in the exact fuel pressure @ carb yet because the truck is going to be working in Southern Oregon at around 3500 to 4500 feet hauling stock.

[jeh]

Well I had a mystery going on with my BBC, I could not get it to stay running after about 10-15 minutes. I put an electric Holley red pump on and no trouble. Still to this day I'm not sure what was going on!!!!

[Mrturner1]

Originally Posted by davepl

I'd never run an electric fuel pump unless I had to (ie: EFI, or if the block doesn't have a boss like the old ZZ502s I've got). I don't think there's any benefit to an electric except as an anti-theft or maybe to prevent vapor lock, but the mechanical pumps on these are so simple and work so well why mess with it?

I was kindof thinking the same thing but wanted to see if there was better performance or reliability to be had.

The other thing I like is that I could hook up a switch under the dash and it would be MUCH harder to steal, also along the same lines you were talking about

[72MARIO]

The only advantage I have seen is with edelbrock carbs. Electric pumps make the truck start right up...............
But to me its at the expense of reliability unless its a in tank pump

[Mrturner1]

Originally Posted by 72MARIO

The only advantage I have seen is with edelbrock carbs. Electric pumps make the truck start right up...............
But to me its at the expense of reliability unless its a in tank pump

This is interesting. I'm running an Edelbrock 650 AVS, but before that I was running an Edelbrock 600 and unless it say for a month, it usually started up after two pumps of the gas pedal and a bump of the key.

[dirtyjim]

both of them fail on a regular basis.
most cheap electrics are exactly that, CHEAP. they are also loud.
for an electric to work properly you will need to run it off a relay and use the proper gauge wire, you will also need a quality regulator. if its an external mount you will also need a 100 micron filter before the pump. if you buy a high end pump see if its serviceable by the end user or has to be sent back to be rebuilt. if your not prepared to do all of that don't expect to have good luck with an electric pump.

stock replacement mechanical pumps have gotten sloppy too, my autozone pump actually puts out 10psi at idle. most of the mechanical pump failures I've had were from leaks, i can't help but think that todays gas with higher ethanol will speed up the deterioration.


i don't have much info on the new piston mechanical pumps, although i am going to try one out on a build soon. since they are designed as a race pump i'm going to have to chat with the manufacture about their durability on a street driven vehicle. i would assume the would work about the same with efi as the belt and cable drive efi pumps.