Rochester Carburetor Flow Ratings
- Feb 7, 2014
Rochester Carburetor flow ratings cfm
Quadrajet: Air flow at 90o air-valve opening
1-3/32-in. venturi (primary) 750
1-7/32-in. venturi (primary) 800
Dualjet
1-3/32-in. venturi 227
1-7/32-in. venturi 287
Varajet (staged 2-barrel)
28mm primary 375
30mm primary 397
Model 2G: 1-1/4-in. flange, 1-7/16-in. throttle bore,
1-3/32-in. venturi 278
Model 2G: 1-1/2-in. flange, 1-11/16-in. throttle bore,
1-3/16-in. venturi 352
1-1/4-in. venturi 381
1-5/16-in. venturi 423
1-3/8-in. venturi 435
Model 4G: Throttle bore & venturi size in inches
1-7/16 – 1-1/8 primary; 1-7/16 – 1-1/4 secondary 486
1-7/16 – 1-1/8 primary; 1-11/16 – 1-15/32 secondary 553
1-9/16 – 1-1/8 primary; 1-11/16 – 1-15/32 secondary 692
Monojet
1-7/16-in. throttle bore, 1-7/32-in. venturi 160
1-11/16-in. throttle bore, 1-5/16-in. venturi 210
1-11/16-in. throttle bore, 1-1/2-in. venturi 250
NOTE:
4-barrels rated at 1.5-in.Hg pressure drop
2-barrels rated at 3.0-in.Hg pressure drop
1-barrels rated at 3.0-in.Hg pressure drop