Good electric fuel pump???

[COREY13]

So my block cracked on my old motor out of my 76 k10 but i got a good low mileage motor out of a 91 k1500 from a buddy of mine. The problem is, that it doesnt have provisions for the mechanical fuel pump, and i was wondering if i could get some recommendations as to a good universal electric fuel pump. The noise of it wont bother me, i just need something pretty good that wont break the bank. The motor is a 350 im converting from tbi to carb, already have a new intake and dizzy, just need the fuel pump. Any help would be great.
Thanks
Charlie

[Burkhalter]

I just got one from O'Reilly's. It works just fine. I did have to run my own wires from the fuse block. But that was easier than cutting the line and installing it.

[hatzie]

I just got one from O'Reilly's. It works just fine. I did have to run my own wires from the fuse block. But that was easier than cutting the line and installing it.

You want some type of fuel pump cutoff just in case you're in an accident. You DO NOT EVER want the fuel pump to remain powered after a collision that shuts down the engine. Fire is an extremely unpleasant way to check out of Hotel Earth.

Use a common Bosch 5 terminal Automotive ISO relay and an Oil Pressure Safety Switch to power the fuel pump. A relay and OPSS is an easier and far more reliable safety cutoff than an inertia switch. The OPSS will eventually fail to turn the pump on. It will not fail to switch the pump off in an emergency like an inertia switch.

A Three terminal Universal OPSS , like the Airtex OS75, has fuel pump power switch contacts that do not close till there's oil pressure to run the fuel pump. These switch contacts open back up as soon as there is no oil pressure immediately shutting it off. Cranking power can be utilized to energize the fuel pump while cranking before oil pressure builds.

Hook Ignition power to the Power terminal on the OPSS.
Hook a wire from the starter Crank terminal to the Crank power terminal on the OPSS. This one is optional to reduce cranking time. Eventually oil pressure from cranking will close the contacts in the OPSS and energize the fuel pump through the relay.

Hook the Fuel Pump power terminal on the OPSS to the relay coil + terminal (#86 on a Bosch Automotive ISO relay)
Hook the relay coil ground to any good chassis ground (#85 on a Bosch Automotive ISO relay).
Hook the relay Switch Common terminal (#30 on a Bosch Automotive ISO relay) to your fuel pump power lead.
Hook the relay Normally Open switch terminal (#87 on a Bosch Automotive ISO relay) to the Pump terminal on the OPSS.
You can add a pump test wire to the relay Normaly Closed switch terminal (#87a on a Bosch Automotive ISO relay)

PDF is clearer than the picture and printable.  oil pressure safety switch PDF

Sent from my SM-P605V using Tapatalk

[roundhouse]

You can also use these as a theft prevention. By using a hidden button instead of the starter wire

You just hold the button down until the oil pressure comes up enough to operate the OPSS

All the old 18 wheelers had that setup to shut down the engine if the oil pressure dropped below 5 psi




Sent from my iPhone using Tapatalk

[hatzie]

You can also use these as a theft prevention. By using a hidden button instead of the starter wire

You just hold the button down until the oil pressure comes up enough to operate the OPSS

All the old 18 wheelers had that setup to shut down the engine if the oil pressure dropped below 5 psi




Sent from my iPhone using Tapatalk

Oil pressure will rise as you crank it.  You could ignore the start terminal but it'll crank longer because the fuel pump won't start till the oil pressure is up.

Sent from my SM-P605V using Tapatalk

[Burkhalter]

I guess I get to do some wiring this weekend.

This why I'm glad that there are smarter and more experienced people than me on here.

[hatzie]

Not super extensive.

Routing along the LH frame rail to the crossmember under the back of the cab following the taillight and fuel sender wiring would be a good idea. 
Use 1/4 or slightly larger split loom or expanding mesh loom over the wires for protection.

I would use 14ga SXL jacketed wire rather than cheap PVC with solder and heatshrink at the ends.  It'll last much longer in the engine bay and under the truck.  You can get it at NAPA or online from Del City, Waytek, etc...  WireBarn, among others, has 10' & 25' SXL 8 & 10 color assortments on evilbay.

I usually socket Mini ISO relays.  Bosch: 3 334 485 008 or Tyco: V23333Z1001A008.  The Bosch socket uses Packard 56 terminals. https://theelectricaldepot.com/relays/relay-connectors-terminals/5-socket-relay-connector-bosh-3-334-485-008-br-5-pack?zenid=ada89c0da502f0b0ceb90733d699179c

There are only three wires that are any serious length and only two runs.  Starter Crank to the OPSS & Relay socket to the fuel pump leads.  Be sure to leave yourself @ 4-6" of extra wire at the termination points. 

You can pick up the pump ground by Teeing into the ground at terminal 85 on the relay.

You can use a two stud 10 Amp Bussman "Short Stop" Self Resetting Circuit Breaker instead of a fuse.  This is what I'm talking about but you can get one locally. http://www.wiringproducts.com/10-amp-short-stop-auto-reset-circuit-breaker-12-volt-parallel.html

Semi-protected battery power is available off the Junction studs next to the brake booster so no need to snake wires all over the engine bay.  Put the relay socket and breaker right next to the J-Block.  It'll be within 10-14" of the OPSS in that position too.  Mount the relay with the wires on the bottom and always make a drip loop by running the wires down toward the ground and then slightly back up from the fuel pump, OPSS, and relay to let any water drip off before it gets to the fragile only slightly sealed parts.

If you don't mind occasionally burning out the OPSS omit the relay.  I figure unplugging the relay from a Bosch socket and plugging in a new one is easier than replacing that switch on the back of the engine.

[COREY13]

Thanks for all of the info, just out of curiosity, how does the oss relay get the oil pressure, i dont have an electronic oil pressure sender, i just have the tube that goes into the block with the analog gauge. And the mr gasket pump they sale at the local parts house is rated at 4 to 9 psi, is there an adjustment on there i can dial in or do i need a seperate regulator?

[hatzie]

Thanks for all of the info, just out of curiosity, how does the oss relay get the oil pressure, i dont have an electronic oil pressure sender, i just have the tube that goes into the block with the analog gauge. And the mr gasket pump they sale at the local parts house is rated at 4 to 9 psi, is there an adjustment on there i can dial in or do i need a seperate regulator?

Screw the Airtex OS75 OPSS onto a 1/8" NPT brass Tee along with your oil pressure capillary tube compression fitting.  You'll likely need a short chunk of brass pipe unless you have room behind the intake to use what's called a "Street Tee"... meaning one fitting of the three is male rather than female.  Why "Street"?  I think the name came from their popular use in municipal water and gas service drops to homes "At the street" with a one piece fitting.

Pick any 20A/30A Bosch type Mini ISO Automotive Relay.  Normally closed contacts are rated less than Normally open contacts for some reason.
This guy--->http://theelectricaldepot.com/  Carries reasonably priced project quantities of relays, relay sockets, Fuses, circuit breakers, various Delphi connectors, and various Delphi terminals along with two grades of crimp and extractor tooling... Good Light DIY and Light Professional.  Unfortunately he only has GP series PVC jacketed wire not XL series Crosslink Polyethylene Jacketed wire. You want SXL wire...
The 12085270 single operation ratcheting light pro tool is around $90 and it will outlast you.  That one tool will "W" crimp most 12-20ga open barrel connectors like Packard 56 & 59 terminals on the wire and insulation along with Metripack and Weatherpack terminal wire and seals.  It works in two operations rather than all at once like the more expensive narrow application tools.  One operation to crimp the wire a second operation for the seal or insulation crimp.  The 12085270 tool is the most used crimp tool in my box next to the Daniels AF8-TH1A Mil. Spec. machined terminal crimp tool that does Closed Barrel Deutsch DT & DTM along with a host of Canon terminals.