2B vs. 4B

[killer medic]

2 Barrel vs. 4 Barrel

I am going to get to this junction very soon. I currently have a 2 barrel carb and intake. I want to build for some more power and get-up, but I am not racing or going to the track. Just something that will move if I have to punch it. However, I want to do halfway decent on gas mileage. I'm not asking for miracle in gas conservation, just a modest savings. Although I know the 4 barrel will help the car breath better, will it be THAT much of an increase in gas consumption? Or can it actually help mileage? Thanks guys!

 

[BornInAFord]

If you're like most of us, your mileage will go down a little due to the fun pedal's increased use...
But... you may get an increase in mileage. Your 2bbl is likely a 390cfm. If you go to a 4bbl (say up to a 600cfm carb), your primaries will only be up to 300cfm, which is somewhat smaller. My Autolite 4100 is a 480cfm, and I can get anywhere from 12-18mpg in town (life's too short to drive "like a grandmother", and between 15 and close to 30mpg on the highway. I converted to a five speed (T5Z with a 3.00 rear and a carbed 5.0L :o ) so your mileage will vary.
Daniel

 

[Rapid]

I'm getting 12-14 in the city and 15-17 on the road with a mild cam, 500 cfm 4 bl Edelbrock Performer, c4 auto, duals and close to a 3.0 rear ratio. Not sure on the rear end. It is great for fun but is definitly not a race car.

 

[D.Hearne]

BornInAFord nailed it. The key to better mileage with a 4 bbl is how well you can control your right foot. My 331-sixpack Ranger has gotten 16 mpg with 3 Holley 2 bbls on it, as along as I drive it conservatively ( the speed limit everywhere and keeping my foot out of the two secondary carbs) If I drive it the way I like to, it'll knock down 12 mpg all day.

 

[wild70stang]

You are right about gas consumption, but if you upgrade other parts of your engine your gas mileage will go up too. I used to get 15 mpg (highway) with stock engine. Now im almost at 20 because of 8mm spark plug wires/new spark plugs, pertronix ignitor and 12v coil, and new air filters. It would also help if you upgraded your cooling system on your engine.