hello,

got a question about carb size,
my engine is a 466 (.30 over) with flat top pistons,
c8 heads, headers, performer intake, comp cam powermax cam, electric waterpump etc, but wich carb should i run?
i`m thinking of a demon 850 vac. sec. w/annular or is this to big?

thanks

 

It all depends on what you are going to use it for I guess. I would say a 750 would work good but a 850 would work well to. All depends on your intended purpose for the vehicle.

 

i`m gonna use it on the street and maybe strip.
thanks

 

Before you can determine carb suze need to know acouple of things. Is it stock except for over bore and how many revs are you going to turn it to? How much cam does the engine have? Unless it is a race motor or a Hi-Po street motor and 850 is way to much and will hurt preformance and fuel economy. They come stock with a 600 because anything past 4500 and the cam runs out of go and the engine needs no more carb. There is a formula to figure what size carb you need.



CFM= RPM X CID Divided by 3456

 

Actually the formula is CFM= RPM times CID divided by 3456 times (VE% divided by 100)

Example: 5000 X 466 / 3456 X .85 = 573.06134259259259259259....CFM. Generally a stock motors VE is in the 78-88 VE range

 

The one I gave works for a street motor just fine and 99.9% of the characters out there always over estimate how efficient their engines are and I figure if you keep it simple, then their egos can't get carried away. I however totally agree with you numbers.

 

Hello, i run a 670cfm Holley street avenger carb on my 460ci along with the Edelbrock performer RPM manifold, my 460ci is 40 thou over, it performs really well. unless you have some work done to your engine a 670cfm or 750cfm vacume secondary should be fine, Jamie. Australia.

 

thanks for the reply`so far