I have been doing some calculations ( actually been using the CFM calculator at a carb site ).
A 24 mm bore ( the 740 primary bore ) will flow plenty good on a 1100 c.c. engine with a 83% volumetric efficiency up to 7,000 RPM !!!
I also read a very interesting post on another website about a dirt track racer who installed a half 500 CFM carb on a 2.3 liter Pinto engine and got black-flagged because it was so fast, compared to running both barrels. Apparently too much CFM is as bad as not enough .......
SO, What I am thinking of doing now with my 740 carb is to modify the secondary linkage so the secondary doesn't start opening until about 85 % throttle opening. Need to stay on that primary mostly, up to about 7,000 RPM.
A 24 mm bore ( the 740 primary bore ) will flow plenty good on a 1100 c.c. engine with a 83% volumetric efficiency up to 7,000 RPM !!!
I also read a very interesting post on another website about a dirt track racer who installed a half 500 CFM carb on a 2.3 liter Pinto engine and got black-flagged because it was so fast, compared to running both barrels. Apparently too much CFM is as bad as not enough .......
SO, What I am thinking of doing now with my 740 carb is to modify the secondary linkage so the secondary doesn't start opening until about 85 % throttle opening. Need to stay on that primary mostly, up to about 7,000 RPM.