EFI to Carb

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Jan 14, 2011 | 12:56 AM

FlatBlak

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Joined: Jan 2011

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EFI to Carb

heres what i have:
a 351W bored .030" over, decked to .004" polished crank and rods, full ARP bolt and stud kit, Comp Thumpr Cam, World Products 210 Iron Heads fully ported 9.5:1 Compression Ratio, Weiand Stealth Intake, Edelbrock 750 Carb. This engine is currently sitting in my 1990 Ford F150 that originally came with a 5.0 efi. I would like to run my set up off of my factory fuel pumps in the tanks (dual tanks) so i realize i would need a fuel pressure regulator as well as a distributor. so i picked these to do the job :Mallory Ignition 4309 - Mallory Fuel Pressure Regulators - Overview - SummitRacing.com and Mallory Ignition 8555401 - Mallory 85 Series HEI Distributors - Overview - SummitRacing.com Now heres what im worried about... How do i make this run? what can i do take out for wiring if any? can i pull the ecu or will it need to stay in the truck? do i just leave it all in and pull the check engine bulb? can i use my factory gauges? will i still be able to choose what tank i can use?. any and all comments will be much appriciated as im having a very hard time finding the answers.

PS. No i am not staying with EFI. Please dont make this another carb vs. efi thread. i know the benifits of both and ive made up my mind.

Jan 14, 2011 | 06:26 AM

L. Ward

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Joined: Nov 2010

Posts: 957

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From: Graniteville

Two things

Your carb is a bit on the large size, even at 95% ve and 7000rpm, the engine only needs 675cfm. At a more realistic 85%ve and 6500rpm, its wanting 560cfm. (Even at 100%ve, at 6500rpm its only 660cfm). If you haven't run it yet, I would suggest changing the carb out for either a Edelbrock 1806 Thunder (650cfm) or a Holley 80670 Street Avenger (670cfm). Personally, I prefer the Holley, but again, that's a personal preferance.
The fuel pressure regulator does not appear to be the one you need. It is designed to be used with hi-volume, lo-pressure pumps. Although I am sure there are probably others out there, the pressure regulator that I have found that works with the factory ford hi-pressure pumps (which your 90 has) is this one Aeromotive 13301 - Aeromotive Universal Bypass Regulators - Overview - SummitRacing.com which will handle the input pressure and still drop the pressure for the carb.

Also, in between the regulator and carb, I run a Spectre Performance 2517 - Spectre Performance Fuel Pressure Regulators - Overview - SummitRacing.com the pressure at my carb stays at a rock solid 5psi with no creep or surge.

On mine, the ECM is still there (altho I am sure it wonders just wtf? is going on under the hood! LOL) but that's because I did not feel like rewiring everything when I changed over. Heres a short list of the change over

Fuel Pump Relay, remove existing ground wire from relay under hood, connect it to full time ground. (The key controls the relay trigger hot, the ecm controls the relay ground. This allows the pumps to run with the key on with the ecm getting funky signals and shutting the pumps off, which was a problem on mine)
Adapt the existing fuel lines to the regulator. On mine, we used a fuel line repair kit to connect the existing plastic supply and return lines to the pressure regulator, which we mounted on the drivers side under the battery tray (I use a dual battery setup from a diesel, on a gasser it would be under the airbox) The rest of it, from the regulator to the carb, is standard rubber fuel line.
Throttle cable from a 80-87 carbed model (a 1987 F250/F350 460 Carbed pickup will work) as the factory EFI cable is too short. You will also need a mounting bracket of some sort for the cable. A factory mount from the same 87 F250/F350 will work on a Holley, Lokar and others also make mounting brackets. Obviously some adaptation may be required.
Remove about 90lbs of wiring harness (I would suggest getting a spare engine harness from the JY) You will need a keyed hot for the elec choke, the factory leads for oil pressure and water temp will work, and use the keyed coil hot for the new coil/ignition.
Air filter. Not alot of room front to back. I run a K&N 12" with the X-treme airflow top on the filter assembly.
Transmission. Depending on the trans you will need to run a controller with a TPS (E4OD), a TV cable (AOD), a kickdown cable (C6) or nothing at all (manual)

I never did get around to adapting the factory tach to work as I was using mine for racing on the weekends, so I had added a monster tach to mine on the top of the dash. I did however piggyback the factory cruise control cable onto the throttle cable and the cruise works just fine.

Oh, and cover or pull the CE bulb as its gonna stay on all the time now as you guessed.

Jan 14, 2011 | 10:15 AM

Conanski

FTE Legend

Joined: Jun 2006

Posts: 31,930

Likes: 1,499

From: Ottawa, Ontario

I think Mr Ward has you covered, that motor should make some impressive power so my only question is what transmission is behind it?

Jan 14, 2011 | 01:24 PM

FlatBlak

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Joined: Jan 2011

Posts: 69

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Wow, thanks, that's exactly what info I needed. I will be running a built C6 with 3300 stall as well as a 8.8 with trac lok and 3.55 gears. I will also be installing an 04-up crown vic aluminum front crossmember and suspension. The rear I'm not sure what to run yet for traction, I'm hoping slicks will get me by

Jan 14, 2011 | 05:25 PM

L. Ward

Elder User

Joined: Nov 2010

Posts: 957

Likes: 2

From: Graniteville

3.55 gears and a 3300 rpm stall are not going to be real happy together. If you are running the Big ***** Thumper you probably need to look at 4.10s at least, and if you are running the Thumper 283, stepping down to a lower stall.

With the ***** Thumper, a TCI streetfighter would work well, with the Thumper 283, a TCI breakaway would work well.

As for the weight on the rear end, you can always make a bracket to mount some weights right over the rear axle and then add dumbells as needed to get enough weight for the launch.

Feb 28, 2011 | 11:13 AM

FlatBlak

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Joined: Jan 2011

Posts: 69

Likes: 1

Quick Question for L. Ward, my parts supplier currently has this fuel pressure reg. will it work or should i just get the one you got?
linky here : Holley 12-803BP - Holley Carburetor Bypass Style Fuel Pressure Regulators - Overview - SummitRacing.com