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Full Version: Push or Pull? Which way would you install?
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computers4kids
I have a Holley blue electric fuel pump that I would like to install in my 75 v-8 conversion. I am trying to decide the best location to install it.

Choice 1: Install it near the stock location up front in the trunk mounting it on the wall that encloses the gas tank facing inward towards the trunk for easy accessibility. Gravity fed from tank and regulated up front also so the lines going back to the carb are only pressurized to 5lbs. Wiring is already there.
+ easy install and wiring is already there
- lines pressurized length of car
+ cooler in front trunk, even with radiator, than engine compartment

Choice 2: Install it in the engine compartment somewhere on the passenger side. The pump would be gravity fed the length of the car and then pressurized and regulated in the engine bay. I would have to run a wire for to power it up.

+ gravity fed so lines are not under pressure in tunnel
- not sure if pump will work as well trying to pull rather than push
- hotter in engine compartment

What would be the better approach?
Thanks

r_towle
push.
Pumps work better when pushing.
Most pumps, certainly low cost ones...dont do well when pulling.

Rich
Joe Bob
Leave it up front if the power and mounting hardware is already there. I'm a fan of recirculating even if you have carbs....
computers4kids
OK...up front was my first choice, but this tip on Holley's website has me thinking a bit.
Click to view attachment
If the pump is up front in the trunk and I put the regulator in the engine bay (like the tip says) I have a question.

If I set the regulator to 5 lbs, obiviously on the carb side the pressure will be 5lbs, but what about the side between the fuel pump and regulator...won't that be pressure up to yang? Or does both the pump side and regulator side balance to 5lb.

You tell I'm a noobie at this confused24.gif

Also, if the pump only has an inlet and outlet, how can I plumb it so the fuel recirculates. I like the idea for many reasons.
orange914
QUOTE(mikez @ Jul 27 2008, 09:18 AM) *

Leave it up front if the power and mounting hardware is already there. I'm a fan of recirculating even if you have carbs....

up front... agree.gif

+++cooler!

just a crazy, maybe overkill way but maybe you could pre-regulate it (in front) down to ...say... 10 p.s.i. before your final regulator at the carbs if you have concerns. i'll bet you have an extra regulator to loop the excess back on a front reg. you are looping (or returning) the fuel from the rear?

i had a complete pump/reg set up from a parted out 914 i wanted to run on my 69 ranchero but i ended up selling the truck first.

mike
computers4kids
QUOTE(neo914-6 @ Jul 27 2008, 03:15 PM) *



QUOTE(orange914 @ Jul 27 2008, 04:07 PM) *

QUOTE(mikez @ Jul 27 2008, 09:18 AM) *

Leave it up front if the power and mounting hardware is already there. I'm a fan of recirculating even if you have carbs....

up front... agree.gif

+++cooler!

just a crazy, maybe overkill way but maybe you could pre-regulate it (in front) down to ...say... 10 p.s.i. before your final regulator at the carbs if you have concerns. i'll bet you have an extra regulator to loop the excess back on a front reg. you are looping (or returning) the fuel from the rear?

i had a complete pump/reg set up from a parted out 914 i wanted to run on my 69 ranchero but i ended up selling the truck first.

mike


Great links and pics...that helps.
Mike, I like your idea of pre regulating the pressure say to 10 and then another regulator in the engine bay to kick it down to 5 and push the excess back to the tank with the return line that is still there. Sounds like it should work. I do have a regulator now, but it's only an in/out...no third port for diverting the excess. If I used it I wouldn't be able to recirculate the fuel.

neo914...I saw you had an aluminum 90 by your water pump...where did you get that and did you have any problems with all the pressure coming right out of the pump and going into an almost immediate 90 turn. Seems like I read that the pressure would be too great and you would blow hoses there. If it works, it would fit much better.

Thanks guys!
messix
that pump is not a high pressure pump, so no worries on the stock plastic lines there rated at much higher than the holley will put out. it's volume that the holley does good. get a regulator that is ment for a return system and run it right up to the carb.

that holley is good but the generic jeggs and summit will do fine and at 30 % discount.
computers4kids
QUOTE(messix @ Jul 27 2008, 07:15 PM) *

that pump is not a high pressure pump, so no worries on the stock plastic lines there rated at much higher than the holley will put out. it's volume that the holley does good. get a regulator that is ment for a return system and run it right up to the carb.

that holley is good but the generic jeggs and summit will do fine and at 30 % discount.


Thanks for the tip...but too late. Picked up a new blue and reg. for $75...so I'm happy.

True about the pressure...Holley is set at 14 and we know the FI lines were generally running 29 lbs. I'll have to see what I can find for a regulator that returns.
LvSteveH
I don't know if anyone has warned you yet, but the holley red and blue pumps are unbelievably freaking loud using the stock mounts.

It will help to mount it on thick rubber isolators, but it's still loud. At idle you'll probably be able to hear it over a raspy V8 exhaust, especially if it's mounted up front. They do prefer to push, but I've seen a holley red mounted in a 914 rear trunk work fine with a healthy V8.

For a typical street 914-8 in the 350hp range the red and are blue really over kill for most people. A track car sees sustained high rpms for long periods where as on the street you almost never get to stay full throttle for more than a few seconds.

Staying on the gas for around 20 seconds in one of my 914 V8's resulted in going from about 70 to 145 or so. Even then I didn't need as much fuel as the red or blue offer.

neo914-6
QUOTE(computers4kids @ Jul 27 2008, 05:10 PM) *


neo914...I saw you had an aluminum 90 by your water pump...where did you get that and did you have any problems with all the pressure coming right out of the pump and going into an almost immediate 90 turn. Seems like I read that the pressure would be too great and you would blow hoses there. If it works, it would fit much better.

Thanks guys!


It's a standard Renegade part, my set up (all Renegade) required it but some have been able to route hoses w/o it...
SirAndy
QUOTE(computers4kids @ Jul 27 2008, 08:15 AM) *

Install it near the stock location up front in the trunk mounting it on the wall that encloses the gas tank facing inward towards the trunk for easy accessibility.


do you have a front mounted radiator? is it shrouded? if not, you'll be dumping all that hot air from your radiator directly onto the fuel pump ...
stirthepot.gif Andy
messix
QUOTE(computers4kids @ Jul 27 2008, 09:26 PM) *

QUOTE(messix @ Jul 27 2008, 07:15 PM) *

that pump is not a high pressure pump, so no worries on the stock plastic lines there rated at much higher than the holley will put out. it's volume that the holley does good. get a regulator that is ment for a return system and run it right up to the carb.

that holley is good but the generic jeggs and summit will do fine and at 30 % discount.


Thanks for the tip...but too late. Picked up a new blue and reg. for $75...so I'm happy.

True about the pressure...Holley is set at 14 and we know the FI lines were generally running 29 lbs. I'll have to see what I can find for a regulator that returns.

great find at that price. here's a reg that will work on return http://store.summitracing.com/partdetail.a...mp;autoview=sku
LvSteveH
QUOTE(computers4kids @ Jul 27 2008, 05:10 PM) *

neo914...I saw you had an aluminum 90 by your water pump...where did you get that and did you have any problems with all the pressure coming right out of the pump and going into an almost immediate 90 turn. Seems like I read that the pressure would be too great and you would blow hoses there. If it works, it would fit much better.



I had a 911 V8 with a 90 degree fitting about six inches off the pump and several times I split the hose at 6000+ rpms when I was setting up the carb. I went to a high flow fitting and Gates Steam King steel braided hose in that section and that seemed to do the trick.

A gates engineer didn't really believe that automotive cooling system pressures could be that high, but he said nothing short of the space shuttle would split the Steam King.
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