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

[Thomas Wright]

I have one small piece of advice, Gasket matching head is OK, but gasket
matching the intake manifold is risky.  Your better off just smoothing
it out and enlarging it only a little.
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.  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


Daniel Burk wrote:

> I'm in the process of porting my intake manifold and was wondering if
> anyone else has done this.
>
> So far I have about four to five hours worth of porting done on the
> first of the eight ports.  I'll try to describe what I've done so far.
>
> I've gasket matched the intake gasket area which involved grinding
> substantial material away from around the roof of the port around the
> injector boss.  There seemed to be a "lip" of some sort that I hope
> wasn't an air deflector 'cause it's gone now.  The overall port size
> now
> matches the gasket perfectly.
>
> The runner gasket area was really weird: Kind of shaped like a
> trumpet,
> so that the opening was already larger than the gasket, but necked
> down
> to the gasket diameter over about a radius of 2 mm.  The gasket is a
> perfect fit to the runner, which is smaller than the intake opening.
> I
> have opened up the port to the diameter of the intake opening to
> remove
> the "trumpet" look.  Substantial material was ground out into the port
>
> about 3cm.
>
> As the port proceeds towards the intake gasket area, it makes a rather
>
> abrupt turn to straighten and turn into the cylinder head.  I've found
>
> that the material in this area is a good .200" thickness, so I have
> ground out about half, about .100" to increase the inside radius of
> the
> turn.
>
> Lastly, I have noted that about .200" material exists in the roof of
> the
> port, so I have raised the roof of the port around the injector boss
> about .050 - .100 ".  I have also lowered the floor of the port at the
>
> runner entrance about .050" to .100" in order to again smooth the
> bend.
>
> Now I DID have one incident that scared me almost ot death:  I hit a
> pore in the aluminum.  It made me think that I had perhaps ground into
> a
> water jacket, but as I examined it, I decided to continue grinding.
> (What the hell, I thought, I'll have to weld anyway if it's through.)
> Luckily, I ground the pore out and it stopped.
>
> Now, Has anyone attempted to port one of these things, and if so, do
> these procedures sound like the right thing to do?  I don't have
> access
> to a flow bench to test them, but would like feed back from
> experienced
> porting people.
>
>         Dan.