Carb suggestions

[Cobradavid]

I'm considering getting rid of the throttle body fuel injection and going to carb, so I'm looking for carb suggestions.

Vehicle is a 1966 Ford Ranchero. Engine is a rebuilt 5.0L w/ high output heads (E7TE-PA), roller lifters, stock cam profile (fits 94-96 Bronco, F-150, E-150, etc.). Intake manifold is a Weiand 8124 Street Warrior.

This truck is not tracked (who races a stock Ranchero? :) ), and I'm looking for driveability. I obviously don't need a huge carb with this engine and application, but the intake manifold drives me to a 4 BBL. With the TB FI system, I already have an in-tank fuel pump, so I know I'll need a fuel pressure regulator and a module to control the electric fuel pump.

What say ye, oh great minds of this forum, what would be good carb choices?

Thanks in advance for the advice.

David

[GoDadGo]

Dave,

I'm a huge fan of the AVS series carbs and have an 800 on my Dark Side MK-4.
JETAV8R has an AVS-2 650 that he's not using and willing to part with.
The AVS-2 has annular primary boosters so you might want to reach out to him if you are looking for a good carb at a great price.
The 650 flows 250 on the primaries with 400 on the secondaries so it's like a Mini-Spreadbore carb.

https://www.youtube.com/watch?v=3npwfIOdKPc&t=68s

Steve

[tony]

I've ran demons on other cars. I just like how easy they are to tune.

[NAZ]

Looking at the specs for the 94-96 302, I calculated the max flow rate required for your engine based on factory specs. At WOT and at 4000 RPM max (peak HP is at 3800) and 75% VE you only need 262 CFM. That would really not be enough CFM demand to choose a four-barrel carb, a two-barrel would be my choice for that engine. If you did go with a four-barrel, I expect it would create a tuning challenge and leave you with drivability issues.


Not sure the issues you had with the EFI but as a side note, you would only need eight 11lb/hr injectors or four 22lb/hr injectors to support this engine.


I would suggest a change in manifold but if you really don’t want that expense and hassle, there are adapters to mount a two-barrel carb on a square port manifold. Search the Summit Racing website for one that will work for you. No question in my mind, go with a Holley two-barrel that will best adapt to your vehicle. The smallest one is a bit more than you need but I'd have no hesitation in using it, a good tuner can make it run well.

[Gordon Levy]

Holley street avenger 570

[Cobradavid]

Thanks for the responses, guys.

Steve,
Thanks for the tip. I read JETAV8R's post about his AVS-2 650 running too rich for his 306. I'm guessing that would be even a bigger problem for my 302 with stock heads and cam.


Tony,
Thanks for the suggestion.


NAZ,
Thanks for the research and the suggestions. Some on-line tools were telling me ~370 CFM (assuming 85% efficiency) was the most I needed.
The FiTech system started out ok, but has gotten worse and worse lately. Now it runs super rich, is fouling plugs, and is very hard to start and keep running. It will not idle at all by itself. Once I do get it running and get it out of the garage, I need to air out the garage for 15-20 minutes just to get the noxious fumes out. It's really bad. The data log shows a lean A/F ratio, so something is really honked up with it. FiTech tech support has been minimally helpful. The system I have is supposed to be "good for up to 400 hp" and it seems like it's trying to make 400 hp with all the fuel it's dumping in the engine.
I"d like to avoid swapping the intake manifold, so going to a 2BBL with an adapter might be the way to go. Do you think that set up will be hard to tune?

Gordon,
Thanks for the suggestion. Is the 570 too much for a stock 302? Will I just end up with hard tuning and bad driveability?


Soooo....... any recommendations/suggestions on 2BBL carbs? :)
Type or brand I should stay away from?
Are there ones that will work better with electric, in-tank fuel pump (with pressure regulator), or does that even matter?
Manual choke or electric choke?

Thanks again in advance!
David

[GoDadGo]

Thanks for the responses, guys.

Steve,
Thanks for the tip. I read JETAV8R's post about his AVS-2 650 running too rich for his 306. I'm guessing that would be even a bigger problem for my 302 with stock heads and cam.
David

The AVS carbs use different metering rod step up springs.
It's like a Holley's power valve but easier to deal with.
All you need is a vacuum gauge and the tuning kit.
Check out Uncle Tony's videos & the Edelbrock AVS:

https://youtu.be/1WNpdy9-zdE

https://youtu.be/aBbD_JlKBGY

[NAZ]

The symptoms you describe on your EFI sounds like an O2 sensor needs calibrating or is going bad. The controller is indicating lean but the AFR is actually pig rich. I’d try resolving that first but if you’re set on a switch to a carb, take a look at this one, it should fit the application.
https://www.holley.com/products/fuel_systems/carburetors/performance_2_barrels/parts/0-80350

[Cobradavid]

Thanks, Naz. I also was thinking the O2 sensor might be bad. I've checked for intake and exhaust leaks and haven't found any, so maybe the sensor is wonky. I might try fiddling with that before I dive into the deep end with a carb conversion.