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Author Topic:   Carbeurator Question...
Dirt Full Roller

Total posts: 52
posted August 23, 2000 05:12 PM UIN: 1986763
Hi All -- I am building up an open show motor for my late model pro/street stock, and have a question...not sure what carbeurator setup to go with. Here is my motor setup...chevy 400 block, 3.875" stroker crank (421"), 6" h-beam rods, JE 13.0:1 pistons, dry sump, herbert roller cam (.654"/.605" lift, 270/284 @ .050), pro action 23 degree heads and port matched intake from AFR (flow 312 cfm at 700 lift). Here is my dilemma, what type of carbeurator would you all run? I am going to run racing gas, and have looked at both the Race Demon's and the Holley 4150HP carbs. Are the Race Demon's really worth the extra $$$ over the Holley? What cfm size would you all recommend? I am looking at the 825 race demon and the 830 4150HP. Any thoughts? The motor will twist 7600-7800RPM on the straights.



Earl Parker II
Dirt Roller

Total posts: 17
posted September 03, 2000 08:13 PM
Before you decide on the exact cfm carb you need, you might want to take into consideration the weight of the car, the size of the track and the minimum rpm the engine will see in the turns.

All else being equal, the heavier the car, the smaller the track and the lower the minimum rpm, the smaller the carb you'll need. Given your engine I'd consider 750 cfm to be the lower limit. If the reverse of the above is true then an 830 cfm unit might be more appropriate.

If you're on the fence flipping a coin, go with the smaller unit. You'll be happier in the long run.

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