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Re: Best Carbs for MG??? What about the manifold?

To: Lawrie Alexander <>
Subject: Re: Best Carbs for MG??? What about the manifold?
From: Jurgen Hartwig <>
Date: Sun, 02 May 1999 18:33:28 -0400

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.  


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And the world rejoiced.
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