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2bbl vs 1bbl carbs, difference?


Hirsch's Avatar
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04-13-05, 11:19 AM   #1  
2bbl vs 1bbl carbs, difference?

I have an 83 Dodge Pickup with the slant 6 225 c.i. engine with a 2bbl carb. It currently gets 12 mpg. I am getting an 85 doge pickup for parts which is the same except it has a 1 bbl carb. Would I gain much in gas mileage and lose a lot of horsepower if I change the truck back to a 1 bbl carb like it was originally? Kind of betwixt and between on the issue. Any advice would be greatly appreciated. Thank y'all much in advance!!

 
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car nut's Avatar
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04-13-05, 03:37 PM   #2  
It is hard to know the correct answer. There are many variables. Assuming both carbs are factory equipment, the 2 barrel may give better mileage if the venturies are small enough. The smaller the venturies the better the fuel will atomize for better efficency. If the total venturi area of 2 barrel carb is greater than the area of the 1 barrel the 2 barrel can give more horsepower.

4 barrel quadrajet carbs usually gave better fuel economy (assuming you did not get into the back two barrels) than a 2 barrel carb because the primary venturies were smaller than the venturies on a 2 barrel carb.

However I would not look for a huge difference either way. But at todays gas prices it can add up.

 
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04-14-05, 12:40 PM   #3  
The carb I have now is a Carter which is factory equipment but not for this truck, which when new came with a 1 barrel, but the previous owner changed it into a 2 barrel for more performance. At least the parts truck I am trying to get home has a kickdown rod in it which mine doesn't, and I have heard that a kickdown rod will make a helathy difference in mileage and performance. It kinda has to since my truck will not downshift now when I floor the gas. Since I am currently putting about $100 a week into the truck at $2.22 a gallon, I would definitely welcome an increase in gas mileage .

 
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