MoparFins

Techical Discussions => Tech- - FUEL => Topic started by: Alan on January 15, 2009, 04:28:04 AM

Title: 2 bbl vrs 4 bbl
Post by: Alan on January 15, 2009, 04:28:04 AM
So I was talking with this guy last night about the less than stellar fuel economy that I get with my 2 bbl. He said I should switch to a 4 bbl because the primaries are smaller in the 4 bbl than the 2 bbl. It sounded plausible, but I don't see that there would be enough, if any, difference in the fuel economy to make it worthwhile going through the hassle of changing it. Plus, once I get my foot into it, I'd use more fuel than with a 2 bbl. Wanted to get some feedback before I go playing mythbusters. 
Title: 2 bbl vrs 4 bbl
Post by: Stan Paralikis on January 15, 2009, 04:42:23 AM
I agree.  You're better off buying those pills that conver t water into gas...



Title: 2 bbl vrs 4 bbl
Post by: Leaburn Patey on January 15, 2009, 06:33:00 AM
It is true that the 4bbl primaries are smaller than the standard 2bbl carb.
Yes,you can gain a few MPG by going 4bbl.
Plus gain a few HP when you wanna stomp on it,too.But then the MPG goes down the toilet.
 
It is all in the way you use it.
 
 Most importantly,it is all in the fine tuning,IMHO--regardless if you have 2 or 4 bbl's to feed.
Most 4bbl carbs have kits available for you to lay with--unlike 2bbls.
Playing with jets sizes,metering rods,recurving distributors,cam,torque convertor and final gears choice all have a play on the recipe. 
I get 16.28 MPG out of my 68 NY'er 440 car.I can drive to Joisey one way on one tank-if I behave!!
I am shooting for 20MPG with the BOAB 383 by going from 2bbl to 4bbl.
Comp Cams 268H cam,one step up from stock in convertor,2.94 gears,duals with HP logs and H pipe.Recurve dizzy and 750 Eddy carb.
My old 2dr Formal NYB had a 2bbl 400 and was a total dog.After doing a 4bbl Thermoquad swap,electronic ignition,it was a joy to drive without hitting every gaz station in sight.
My 77 Dodge P/U was 2bbl 400 and I sold it before I did a 4bbl swap.For what I paid for it and what i wasted in gaz --I bought over a few dozen times. 
 
CBarge2009-01-15 11:50:07
Title: 2 bbl vrs 4 bbl
Post by: Steve on January 15, 2009, 07:48:33 AM
[/QUOTE]
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Title: 2 bbl vrs 4 bbl
Post by: Stan Paralikis on January 15, 2009, 10:09:57 AM
What ?! (http://www.moparfins.com/forum/smileys/smiley26.gif)