Tunnel Ram Carbs

[SPARKY]

I am trying to understand carb sizing:

A formula I found CIDXRPM dived by 3456= carb flow need

My 565 eng x 8500 dev. by 3456   comes out to just shy of needing 1400 cu ft flow


In the past I had run it with a 2000 cuft TB when I ran efi

now I am considering a Dart tunnel ram and trying to decide

2 4150 750
2 4250 850  these could be mounted side ways or length ways

2 4500  1050

I have no race experience with dual carbs and( very little with single)  but know that there are all kinds of different circuits in carbs

What seems to work and and what doesn't---this will only be run at B'Ville and El Miriage with a 565-582 eng.   I have shifted as high as 8500 but never less that 7800  goes through the traps at 6850 to 7500  presently peak power is at 7150 with a single 1250.

[RichFox]

All I know is that in the past I have run with way more advertised CFM that any chart recommends. And I found the 4500 series carburetor to work very well for me. How about putting a bug catcher on it and running injection?

[ronnieroadster]

 I had good luck working with Quick Fuel Technology they helped me with the new combination for my LSR project. The tech people asked my a lot of questions about the system i was repalcing{called me back three times} I was impressed by their efforts.
  The carb they built included how to change the tune from the East Coast to what I need for the Salt. The cost for the carb was only about $30.00 more than the same brand and size CFM carb from Summit or Jegs. I tried two other carb experts with not much success Quick Fuel worked for me.

[revolutionary]

two 4500 1050's will be the way to go.  I highly recommend calling Patrick at Pro Systems carburetors. I have had him make many carbs for me for various applications and they are always really well performing.