Join Date: Jan 2006
Location: the sewer of New York state (Rochester)
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Joined: 10 Jan 2006
Posted: Mon Feb 11, 2008 7:46 pm Post subject:
Put a two barrel on it such as a Holley 2300 series with a four to two adapter. Hey, at least you can stuff the little pedal to the floor and still be on two barrels only.
Absolutly backwards thinking.
If you need a carb that would allow a 460 to turn 4000 RPM, your looking at a minimum of a 500 cfm 2bbl. So your looking at a 2bbl carb with a venturi and throttle plates the same as a 1050 cfm 4bbl.
Now, if you need 500 cfm in a 4bbl, you can get buy with 2 primary throttle bores that are capable of only 250cfm, and use a progressive linkage, and have the second set open only when needed and or about half throttle. So most of the time your pulling high velocity air through a much smaller passage, with better atomization and distrobution.
A 4bbl with a driver that can keep a steady foot, is going to be about 3 times more efficent than a comparable 2bbl.
Thanks for the math 101 class Kim.
Now I can explain a true and tested method for you. A few years back I put together a mild 355" Chevy motor for a full size four wheel Blazer. Crower beast hyd cam, headers, mild port work, etc. Turbo 350, 2400 stall conv, 3.73 gear 35" tire. Surely not a rocket set up for a 4000 pound plus truck. I ran a 780VS Holley, a 600VS Holley and a two barrel 350 Holley. Which one pulled the best, the 780. Which one got the best mileage the 350 two barrel by a long shot. The 350 could get 18 MPG average, the 600 got 14 and the 780 got 12 with the same driving style. Was the 350 2bbl a dog, not really and you could get 5 grand out of it . Being the truck would need more gear and or motor to stick you in the seat the small carb really didn't come in to play that bad. It could still lay down a nice 40' burnout with the two barrel. And pull a 5000 trailer at 75 with no problem. Now if you want to drive without ever opening the secondaries sure the 600 would get better mileage. But I prefer to get on the expressway at 60 not 40 by pushing the pedal down.