DeTomaso Mailing List: April 2000, Message #267

If you actually buy an Eddlebrock Performer intake new for the Cleveland.
you get a piece of paper with it describing the reason for for the small
ports, and yess, it is to increase port velocety.

Dave "bought mine new" D

At 11:57 PM 4/9/00 -0500, you wrote:
>John wrote:
>
>>[snip}  Just pulled the edelbrock "F351-4V" manifold off to polish 
>it.  But the port size difference between the two jumped out and bit me.
Got 
>out the vernier caliper and measured the two.  The heads are big 2.5" x
1.75" 
> and the manifold measured in at 2.15" x 1.38"
>
>>>>I believe one of the Dan Joneseses determined that Edelbrock purposely 
>made the intake runners undersized because they felt the 351C-4V ports were 
>just TOO big for efficient combustion.  Reducing the side of the port (while 
>keeping the volume of air/fuel flow the same) results in increased velocity, 
>and presumably more power.  The mismatch when the air is flowing from a
small 
>to a big opening is a relatively trivial problem; it's when you are trying
to 
>force air from a big hole into a small one that you run into difficulties.
>
>I believe...:>)
>
>I think you're okay.
>
>Mike
>
>
>