Lawrie Alexander wrote:
>
> Neil........
>
> I'm afraid your multi-paragraph question lost me somewhere so I guess the
> answer is - No, we can't talk about manifolds.
>
> Actually, the theory you reference makes sense to me - a straight manifold
> should permit better airflow at very high rpm. At low to moderate rpm, it
> doesn't seem to make any difference. In fact, the turbulence seems to
> improve low-end torque for some reason. Ever looked at the intake manifold
> of a pre-war car? All twists and turns with, usually, one small and poorly
> engineered carburetor sitting at ninety degrees to part of it. Those motors
> usually made lots (comparatively) of low end grunt but had no capability for
> revving very high.
Long, big runners for the manifold help at higher rpms, since they
permit greater flow, as common sense would suggest. The turbulence
generated by the losses from a bending pipe helps to keep and induce
better fuel atomization. The smaller diameter manifolds also help
torque, since they keep the mixture at a higher velocity, thereby
increasing and maintaining mixing.
jay
--
When you were born you cried
And the world rejoiced.
Live your life so in death you rejoice
And the world cries.
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