[FC] 140 head flow and low end for a brier?

[James Davis]

There are dozens of Ultra Vans that run 140 heads with two carbs.  With a 
heavy weight and Powerglide, there is little reason to wind the engine 
out.  The stock carbs flow 87 cfm each and the heads have a maximum 
efficiency of 83%.  Figuring a 168 cuin engine that is turning 4,000 rpm 
requires 161 cuft of air/fuel per minute the two carbs are sufficient. Now 
if you do some head work, run a radical cam (say an OT-30)  with a 4-speed 
then the other carbs become a necessity. I have a 140 Rampside with a Ray 
Sedman cam and heads, headers and a few other goodies.  It definitely needs 
the second set of carbs.  It all depends on your cam, heads and the rpm 
range you intend to drive in.
Jim Davis

At 10:58 PM 7/6/2003 -0700, you wrote:
>I have a question about 140 heads and how they flow.  I know the larger 
>valves
>in a 140 allow more air/fuel flow, and this flow occurs at higer RPM's which
>allow for a greater power (acceleration) at higher speeds.  Because of the 
>need
>for more flow, the secondaries were added.
>Now, if the secondaries were blocked off would this mean that not as much 
>flow
>would go through the valves?  Would only the amount of flow that a 110 head
>would have go through the vales? Or, would it be 1/2 the flow of the 140 head
>with the secondaries on?  OR, would the lack of flow through the secondary be
>picked up by the primary and there would be no flow difference at the valves?
>Has anyone done any studies of this?
>The reason I ask is I have the oppertunity to get some 140 heads and I would
>put them on my greenbrier (an automatic with a non-FC tranny and ofcourse no
>tranny cooler).  I know the greenbrier needs as much low end as it can 
>get, so
>would putting 140 heads on it take away from the low end and give at the high
>end?  What if the secondaries where blocked off?  Could a low end cam be 
>put in
>it to compensate for the 140 high end power?
>Just some thoughts?
>Mike Emanuele, could you contact me on or off list about your 140 
>conversion?
>I would like to ask some more questions.  I joined just a while ago and I am
>not sure if you made postings on your findings?
>
>
>Harry