get electric or mechanical pump? and what size?

peacesdime94 · 06-06-2009, 05:54 PM

looking at getting a electric fuel pump when i get my fuel cell put in my truck i am trying to find out what size pump i will need.

it is a 91 sonoma with a pre 87 SBC 355 edelbrock intake and carb

any info would be great!

there is already an aftermarket electric pump hooked to the stock pump but i am thinking about oging ahead and replacing it.

also what is the difference in mechanica and electric fuel pump? how do you hook up mechanical? pro's and con's?

peacesdime94 · 06-06-2009, 06:17 PM

i dont know much about this if you cant tell! haha

ArtosDracon · 06-06-2009, 09:35 PM

A mechanical fuel pump would be mounted to the engine and the crank would compress a lever inside the block that would compress a diaphram inside the pump to push fuel up into the carb, then release the lever, opening the diaphram back up that will suck fuel from the tank, the reason they don't push or pull from the wrong side of the pump is a pair of basic one-way valves. An electric pump can be mounted either in the tank or in the fuel line just about anywhere, though the reccomendation is usually close to the tank and below it. You do not want the pump to ever suck dry if at all possible. Either one should work just fine.

peacesdime94 · 06-07-2009, 12:01 AM

mechanical sounds too confusing i like the electric lol thank you though now i know

sadexcuse4s10 · 06-07-2009, 12:26 AM

haha

how is a manual pump confusing man? all you do is bolt it to the engine block. hook one hose to the fuel line from the tank and run a hose from the pump to the carb

no wiring at all

Chevhead89 · 06-07-2009, 04:01 AM

hay there artos did ya mean cam...

ArtosDracon · 06-07-2009, 08:33 AM

I did indeed, good catch, last night was a long night, they've all been long nights lately though.

Chevhead89 · 06-07-2009, 10:47 AM

x2 on that man. if ya look i didnt post that up till about 3 am. was workin a customers engine. i hate morons...

s10-den · 06-07-2009, 10:50 AM

Put a machenical pump on and be done. Just that simple

peacesdime94 · 06-07-2009, 11:18 AM

just bolt it up? maybe when i read it i made it seem like more than it is. i'm still trying to put it together in my mind sorry. i'm not the best when it come to engines i can do enough to get by but cant figure this one out

s10-den · 06-07-2009, 11:36 AM

As long as the motor has the fuel pump rod in it,put a block mounted pump on it and use the original fuel lines and thats all there is to it.

peacesdime94 · 06-07-2009, 04:32 PM

where is this said rod?

solenoid · 06-07-2009, 05:56 PM

Passenger side there should be an opening with 4 bolts around the perimeter.Theres a small hole inside ,aproximetly 3/8 in diameter that goes straight through to the camshaft.If you dont already have one go to your local parts house or junkyard and get a fuel pump push rod. Put some heavy grease on said push rod ( all around it so it stays inthe block ). Put the mounting plate with gasket on the block using only the 2 bottom bolt holes , then put the fuel pump in with with gasket ,making sure the fuel pump arm is under the pushrod . Atatch fuel lines bingo your done.

peacesdime94 · 06-07-2009, 06:50 PM

sweet i'll get that checked out! from ones i have found mechanical pumps are cheaper unless i looking wrong place

dre0227 · 06-08-2009, 01:27 AM

A mechanical will work just fine for you and be a lot easier. Like every said bolt on, hook up fuel lines and be done.

peacesdime94 · 06-08-2009, 07:11 PM

ok one more question........... the fuel cell i bought doesn't have the foam in it...is this a MUST have thing? or is it ok not to have any foam in it?

and if i do need it how do i put it in? just buy the foam and shove it in there?

dre0227 · 06-08-2009, 11:09 PM

Just put some spray foam in it.

draggindime072010 · 10-12-2009, 07:19 PM

i know this is kinda an old thread but i didnt want to start a new one

i have a mechanical pump on my motor and i need to hook up the fuel lines

does any1 know what size fittings i will need to run a stainless braided line from the filter on the driver side framerail to the pump on my motor

i will be using 3/8 inch line and im getting it all from jegs

i dont know what size threads my stock filter has and i also need to know the thread size for the one on the pump that goes up to the carb

my motor is a 350 from a 71 chevelle if that matters

Maverick2664 · 10-12-2009, 07:40 PM

the threads on the pump (mechanical) outlet and the inlet on the carb's fuel rail are the same, and the threads are the same as a 3/8 brake line nut, we just plumbed a 383 we ran on our test stand

as for the what the fuel filter on the frame rail is i dont know, but theres a good chance its the same size/threads as the one on the fuel pump

draggindime072010 · 10-12-2009, 09:06 PM

ok so is 3/8 brake line nut different than any other 3/8 fitting cuz i bought what i needed in regular 3/8 fittings and it was too big

Maverick2664 · 10-12-2009, 10:18 PM

i dont know, we keep an inventory of AN and JIC fittings at work, ill see what fits into the fuel pump, both inlet and outlet

Maverick2664 · 10-12-2009, 11:01 PM

think i may have found something.... a size/thread comparison chart, looks like sizes are not constant across the board

http://en.wikipedia.org/wiki/AN_thread

draggindime072010 · 10-13-2009, 12:31 AM

ok so i guess i need -3 sized AN fittings

i might just call jegs before i place the order and let them help me out

i did see this jegs mechanical fuel pump fitting kit and all the thread sizes are 1/4 inch

http://www.jegs.com/i/JEGS/555/15940...ductId=1061702

im sure i have a couple 1/4 inch fittings laying around if i can find them i will see if they thread into my pump and filter

draggindime072010 · 10-13-2009, 12:47 AM

ok i tried a 1/4 inch fitting and it was to small for the outlet on the pump and i tried a 3/8 plug that i had and it kinda sorta fit but the threads werent right for it

so i dont know i dont understand the AN type fittings

maverick how did you run the fuel line to your pump?

i just want to run a stainless braided line from my filter to the pump using 5 foot of the braided line

thats what im gonna tell jegs when i call them lol

Maverick2664 · 10-13-2009, 01:23 PM

well since its a test stand, all we used was a rubber hose with hose clamps to run from the tank to the pump

im on my lunch right now, i didnt get a chance to fiddle with any fittings this morning, maybe ill head back early so i can do that for ya

draggindime072010 · 10-13-2009, 05:25 PM

thanx for your help man.

i could do the rubber hose with clamps but that just doesnt seem to safe to run from the pump to the filter for a permanent line

s10_chevy17 · 10-13-2009, 09:51 PM

if your using the mechanical pump can you still use the stock tank?
n my 86 2.8 what would i do with the fuel pump and sending unit in the tank and/or the extra lines

draggindime072010 · 10-13-2009, 10:02 PM

you can use the stock tank and i have been told that i could just kill power to the pump and it will work

also i have been told that i will have take the pump out and extend the line on the sending unit to reach the bottom of the tank and reinstall everything

im trying it first without doing anything with the pump if that doesnt work i will pull it out

sadexcuse4s10 · 10-13-2009, 10:09 PM

you can leave the stock pump in.

just unplug the power connector at the top of the tank

Chevhead89 · 10-14-2009, 12:23 AM

some get lucky and itll pull through the stock pump fine. and others dont.
just try it out.

Maverick2664 · 10-14-2009, 01:41 PM

well i messed around with various fitting this morning and none of the AN fittings worked, its a different type of thread, so far the only thing ive found that screws into it is like i said, a 3/8 brake line nut... this is for the outlet on the pump

as for the inlet on the pump is just a flanged male tube, if you got rid of the flange you could use a compression fitting

you are using a carb correct? why the need for crazy high pressure fittings? carbs operate around only 7-8 psi and the only line thats pressurized is the one between the pump on the engine and the carb, from the engine back there isnt any at all.... a rubber hose and a few clamps is more than enough for a carb

draggindime072010 · 10-14-2009, 05:50 PM

well i was just thinking i needed the braided line cuz my fuel line will have to run right under my oilpan and i thought it might get the line to hot and make it leak or something im sure i could think of a better way to route it tho

Maverick2664 · 10-14-2009, 07:06 PM

if your oil is hot enough to cause surrounding lines to fail... you have other problems

draggindime072010 · 10-14-2009, 10:54 PM

lol ok well good then i dont have to worry about getting the braided line i can get this thing running tomorrow hopefully

still need to get my driveshaft shortened tho

06-06-2009, 05:54 PM	#1
peacesdime94 Registered User Age: 22 Join Date: Jan 2006 Posts: 499 Location: oakwood, il User is: OffLine	get electric or mechanical pump? and what size? looking at getting a electric fuel pump when i get my fuel cell put in my truck i am trying to find out what size pump i will need. it is a 91 sonoma with a pre 87 SBC 355 edelbrock intake and carb any info would be great! there is already an aftermarket electric pump hooked to the stock pump but i am thinking about oging ahead and replacing it. also what is the difference in mechanica and electric fuel pump? how do you hook up mechanical? pro's and con's?
	[Reply w/Quote]

06-06-2009, 06:17 PM	#2
peacesdime94 Registered User Age: 22 Join Date: Jan 2006 Posts: 499 Location: oakwood, il User is: OffLine	Re: get electric or mechanical pump? and what size? i dont know much about this if you cant tell! haha
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06-06-2009, 09:35 PM	#3
ArtosDracon Registered User Age: 24 Join Date: May 2008 Posts: 814 Location: User is: OffLine	Re: get electric or mechanical pump? and what size? A mechanical fuel pump would be mounted to the engine and the crank would compress a lever inside the block that would compress a diaphram inside the pump to push fuel up into the carb, then release the lever, opening the diaphram back up that will suck fuel from the tank, the reason they don't push or pull from the wrong side of the pump is a pair of basic one-way valves. An electric pump can be mounted either in the tank or in the fuel line just about anywhere, though the reccomendation is usually close to the tank and below it. You do not want the pump to ever suck dry if at all possible. Either one should work just fine.
	[Reply w/Quote]

06-07-2009, 12:01 AM	#4
peacesdime94 Registered User Age: 22 Join Date: Jan 2006 Posts: 499 Location: oakwood, il User is: OffLine	Re: get electric or mechanical pump? and what size? mechanical sounds too confusing i like the electric lol thank you though now i know
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06-07-2009, 12:26 AM	#5
sadexcuse4s10 Hoods are overrated Age: 26 Join Date: Apr 2004 Posts: 11,523 Location: Lexington, NC User is: OffLine	Re: get electric or mechanical pump? and what size? haha how is a manual pump confusing man? all you do is bolt it to the engine block. hook one hose to the fuel line from the tank and run a hose from the pump to the carb no wiring at all
	[Reply w/Quote]

06-07-2009, 04:01 AM	#6
Chevhead89 Registered User Join Date: Aug 2008 Posts: 490 Location: Cocoa, Fl User is: OffLine	Re: get electric or mechanical pump? and what size? hay there artos did ya mean cam...
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06-07-2009, 08:33 AM	#7
ArtosDracon Registered User Age: 24 Join Date: May 2008 Posts: 814 Location: User is: OffLine	Re: get electric or mechanical pump? and what size? I did indeed, good catch, last night was a long night, they've all been long nights lately though.
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06-07-2009, 10:47 AM	#8
Chevhead89 Registered User Join Date: Aug 2008 Posts: 490 Location: Cocoa, Fl User is: OffLine	Re: get electric or mechanical pump? and what size? x2 on that man. if ya look i didnt post that up till about 3 am. was workin a customers engine. i hate morons...
	[Reply w/Quote]

06-07-2009, 10:50 AM	#9
s10-den takes 2 balls in our game Age: 37 Join Date: Nov 2005 Posts: 4,416 Location: florida User is: OffLine	Re: get electric or mechanical pump? and what size? Put a machenical pump on and be done. Just that simple
	[Reply w/Quote]

06-07-2009, 11:18 AM	#10
peacesdime94 Registered User Age: 22 Join Date: Jan 2006 Posts: 499 Location: oakwood, il User is: OffLine	Re: get electric or mechanical pump? and what size? just bolt it up? maybe when i read it i made it seem like more than it is. i'm still trying to put it together in my mind sorry. i'm not the best when it come to engines i can do enough to get by but cant figure this one out
	[Reply w/Quote]

06-07-2009, 11:36 AM	#11
s10-den takes 2 balls in our game Age: 37 Join Date: Nov 2005 Posts: 4,416 Location: florida User is: OffLine	Re: get electric or mechanical pump? and what size? As long as the motor has the fuel pump rod in it,put a block mounted pump on it and use the original fuel lines and thats all there is to it.
	[Reply w/Quote]

06-07-2009, 04:32 PM	#12
peacesdime94 Registered User Age: 22 Join Date: Jan 2006 Posts: 499 Location: oakwood, il User is: OffLine	Re: get electric or mechanical pump? and what size? where is this said rod?
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06-07-2009, 05:56 PM	#13
solenoid bad s-10's brewing Age: 35 Join Date: Mar 2008 Posts: 86 Location: User is: OffLine	Re: get electric or mechanical pump? and what size? Passenger side there should be an opening with 4 bolts around the perimeter.Theres a small hole inside ,aproximetly 3/8 in diameter that goes straight through to the camshaft.If you dont already have one go to your local parts house or junkyard and get a fuel pump push rod. Put some heavy grease on said push rod ( all around it so it stays inthe block ). Put the mounting plate with gasket on the block using only the 2 bottom bolt holes , then put the fuel pump in with with gasket ,making sure the fuel pump arm is under the pushrod . Atatch fuel lines bingo your done.
	[Reply w/Quote]

06-07-2009, 06:50 PM	#14
peacesdime94 Registered User Age: 22 Join Date: Jan 2006 Posts: 499 Location: oakwood, il User is: OffLine	Re: get electric or mechanical pump? and what size? sweet i'll get that checked out! from ones i have found mechanical pumps are cheaper unless i looking wrong place
	[Reply w/Quote]

06-08-2009, 01:27 AM	#15
dre0227 It is what it is bitch... Join Date: May 2007 Posts: 1,952 Location: MN User is: OffLine	Re: get electric or mechanical pump? and what size? A mechanical will work just fine for you and be a lot easier. Like every said bolt on, hook up fuel lines and be done. Last edited by dre0227 : 06-08-2009 at 01:30 AM.
	[Reply w/Quote]

06-08-2009, 07:11 PM	#16
peacesdime94 Registered User Age: 22 Join Date: Jan 2006 Posts: 499 Location: oakwood, il User is: OffLine	Re: get electric or mechanical pump? and what size? ok one more question........... the fuel cell i bought doesn't have the foam in it...is this a MUST have thing? or is it ok not to have any foam in it? and if i do need it how do i put it in? just buy the foam and shove it in there?
	[Reply w/Quote]

06-08-2009, 11:09 PM	#17
dre0227 It is what it is bitch... Join Date: May 2007 Posts: 1,952 Location: MN User is: OffLine	Re: get electric or mechanical pump? and what size? Just put some spray foam in it.
	[Reply w/Quote]

10-12-2009, 07:19 PM	#18
draggindime072010 ROLL TIDE!!!!!! Age: 17 Join Date: Mar 2009 Posts: 958 Location: User is: OffLine	Re: get electric or mechanical pump? and what size? i know this is kinda an old thread but i didnt want to start a new one i have a mechanical pump on my motor and i need to hook up the fuel lines does any1 know what size fittings i will need to run a stainless braided line from the filter on the driver side framerail to the pump on my motor i will be using 3/8 inch line and im getting it all from jegs i dont know what size threads my stock filter has and i also need to know the thread size for the one on the pump that goes up to the carb my motor is a 350 from a 71 chevelle if that matters
	[Reply w/Quote]

10-12-2009, 07:40 PM	#19
Maverick2664 Heavy Metal Body Man Age: 25 Join Date: Jun 2007 Posts: 2,843 Location: Erie PA User is: OffLine	Re: get electric or mechanical pump? and what size? the threads on the pump (mechanical) outlet and the inlet on the carb's fuel rail are the same, and the threads are the same as a 3/8 brake line nut, we just plumbed a 383 we ran on our test stand as for the what the fuel filter on the frame rail is i dont know, but theres a good chance its the same size/threads as the one on the fuel pump
	[Reply w/Quote]

10-12-2009, 09:06 PM	#20
draggindime072010 ROLL TIDE!!!!!! Age: 17 Join Date: Mar 2009 Posts: 958 Location: User is: OffLine	Re: get electric or mechanical pump? and what size? ok so is 3/8 brake line nut different than any other 3/8 fitting cuz i bought what i needed in regular 3/8 fittings and it was too big
	[Reply w/Quote]

10-12-2009, 10:18 PM	#21
Maverick2664 Heavy Metal Body Man Age: 25 Join Date: Jun 2007 Posts: 2,843 Location: Erie PA User is: OffLine	Re: get electric or mechanical pump? and what size? i dont know, we keep an inventory of AN and JIC fittings at work, ill see what fits into the fuel pump, both inlet and outlet
	[Reply w/Quote]

10-12-2009, 11:01 PM	#22
Maverick2664 Heavy Metal Body Man Age: 25 Join Date: Jun 2007 Posts: 2,843 Location: Erie PA User is: OffLine	Re: get electric or mechanical pump? and what size? think i may have found something.... a size/thread comparison chart, looks like sizes are not constant across the board http://en.wikipedia.org/wiki/AN_thread
	[Reply w/Quote]

10-13-2009, 12:31 AM	#23
draggindime072010 ROLL TIDE!!!!!! Age: 17 Join Date: Mar 2009 Posts: 958 Location: User is: OffLine	Re: get electric or mechanical pump? and what size? ok so i guess i need -3 sized AN fittings i might just call jegs before i place the order and let them help me out i did see this jegs mechanical fuel pump fitting kit and all the thread sizes are 1/4 inch http://www.jegs.com/i/JEGS/555/15940...ductId=1061702 im sure i have a couple 1/4 inch fittings laying around if i can find them i will see if they thread into my pump and filter
	[Reply w/Quote]

10-13-2009, 12:47 AM	#24
draggindime072010 ROLL TIDE!!!!!! Age: 17 Join Date: Mar 2009 Posts: 958 Location: User is: OffLine	Re: get electric or mechanical pump? and what size? ok i tried a 1/4 inch fitting and it was to small for the outlet on the pump and i tried a 3/8 plug that i had and it kinda sorta fit but the threads werent right for it so i dont know i dont understand the AN type fittings maverick how did you run the fuel line to your pump? i just want to run a stainless braided line from my filter to the pump using 5 foot of the braided line thats what im gonna tell jegs when i call them lol
	[Reply w/Quote]

10-13-2009, 01:23 PM	#25
Maverick2664 Heavy Metal Body Man Age: 25 Join Date: Jun 2007 Posts: 2,843 Location: Erie PA User is: OffLine	Re: get electric or mechanical pump? and what size? well since its a test stand, all we used was a rubber hose with hose clamps to run from the tank to the pump im on my lunch right now, i didnt get a chance to fiddle with any fittings this morning, maybe ill head back early so i can do that for ya
	[Reply w/Quote]

10-13-2009, 05:25 PM	#26
draggindime072010 ROLL TIDE!!!!!! Age: 17 Join Date: Mar 2009 Posts: 958 Location: User is: OffLine	Re: get electric or mechanical pump? and what size? thanx for your help man. i could do the rubber hose with clamps but that just doesnt seem to safe to run from the pump to the filter for a permanent line
	[Reply w/Quote]

10-13-2009, 09:51 PM	#27
s10_chevy17 Registered User Age: 25 Join Date: May 2005 Posts: 249 Location: User is: OffLine	Re: get electric or mechanical pump? and what size? if your using the mechanical pump can you still use the stock tank? n my 86 2.8 what would i do with the fuel pump and sending unit in the tank and/or the extra lines
	[Reply w/Quote]

10-13-2009, 10:02 PM	#28
draggindime072010 ROLL TIDE!!!!!! Age: 17 Join Date: Mar 2009 Posts: 958 Location: User is: OffLine	Re: get electric or mechanical pump? and what size? you can use the stock tank and i have been told that i could just kill power to the pump and it will work also i have been told that i will have take the pump out and extend the line on the sending unit to reach the bottom of the tank and reinstall everything im trying it first without doing anything with the pump if that doesnt work i will pull it out
	[Reply w/Quote]

10-13-2009, 10:09 PM	#29
sadexcuse4s10 Hoods are overrated Age: 26 Join Date: Apr 2004 Posts: 11,523 Location: Lexington, NC User is: OffLine	Re: get electric or mechanical pump? and what size? you can leave the stock pump in. just unplug the power connector at the top of the tank
	[Reply w/Quote]

10-14-2009, 12:23 AM	#30
Chevhead89 Registered User Join Date: Aug 2008 Posts: 490 Location: Cocoa, Fl User is: OffLine	Re: get electric or mechanical pump? and what size? some get lucky and itll pull through the stock pump fine. and others dont. just try it out.
	[Reply w/Quote]

10-14-2009, 01:41 PM	#31
Maverick2664 Heavy Metal Body Man Age: 25 Join Date: Jun 2007 Posts: 2,843 Location: Erie PA User is: OffLine	Re: get electric or mechanical pump? and what size? well i messed around with various fitting this morning and none of the AN fittings worked, its a different type of thread, so far the only thing ive found that screws into it is like i said, a 3/8 brake line nut... this is for the outlet on the pump as for the inlet on the pump is just a flanged male tube, if you got rid of the flange you could use a compression fitting you are using a carb correct? why the need for crazy high pressure fittings? carbs operate around only 7-8 psi and the only line thats pressurized is the one between the pump on the engine and the carb, from the engine back there isnt any at all.... a rubber hose and a few clamps is more than enough for a carb
	[Reply w/Quote]

10-14-2009, 05:50 PM	#32
draggindime072010 ROLL TIDE!!!!!! Age: 17 Join Date: Mar 2009 Posts: 958 Location: User is: OffLine	Re: get electric or mechanical pump? and what size? well i was just thinking i needed the braided line cuz my fuel line will have to run right under my oilpan and i thought it might get the line to hot and make it leak or something im sure i could think of a better way to route it tho
	[Reply w/Quote]

10-14-2009, 07:06 PM	#33
Maverick2664 Heavy Metal Body Man Age: 25 Join Date: Jun 2007 Posts: 2,843 Location: Erie PA User is: OffLine	Re: get electric or mechanical pump? and what size? if your oil is hot enough to cause surrounding lines to fail... you have other problems
	[Reply w/Quote]

10-14-2009, 10:54 PM	#34
draggindime072010 ROLL TIDE!!!!!! Age: 17 Join Date: Mar 2009 Posts: 958 Location: User is: OffLine	Re: get electric or mechanical pump? and what size? lol ok well good then i dont have to worry about getting the braided line i can get this thing running tomorrow hopefully still need to get my driveshaft shortened tho
	[Reply w/Quote]