Info needed on porting details for a stock Tuned Port Intake manifold

[Thomas Wright]

Clint Sharp wrote:

> In message <33B7318C.2D13E7DB at garnet.acns.fsu.edu>, Thomas Wright
> <tgw3448 at garnet.acns.fsu.edu> writes
> >I have one small piece of advice, Gasket matching head is OK, but
> gasket
> >matching the intake manifold is risky.
>
> >If you gasket match the head AND the intake manifold, there is no
> >guarantee that they will match up perfectly when bolted together.
> There
> >will always be some play when mounting the manifold (and the gasket)
> on
> >the head, and if there is even the smallest area where the incoming
> air
> >hits an even slightly protruding edge of the manifold gasket or head,
>
> >then all your porting work will be undone.

> How about dowelling the manifold and head and then doing the flow
> work?
> You are then guaranteed alignment unless you screw up the dowels

Of course, you're right about that, and believe it or not, I new about
that solution, but is it really worth it?  I would be willing to bet
that if you tested it on a bench, that you could not even measure the
benefit of having it matched that closely.  In real life, however, there
is a real benefit to the anti reversion properties of a smaller intake
manifold port>larger head port (reversed on the exhaust side),
especially if running radical cams. (which I assume any gasket matcher
would be doing!) Also, the real price of messing up way exceeds any
theoretical benefit.

> >  ALWAYS leave the intake
> >manifold port slightly smaller in diameter than the head port.
> Moving
> >from a smaller port to a larger one won't disrupt the flow in any
> >measurable sense, and in addition, the anti-reversion properties are
> >more beneficial than a perfectly matched port (which is next to
> >impossible to achieve anyhow.)
>
> >Tom Wright
>
> --
> Clint Sharp

Tom Wright