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What about the port? was: Do these things work?
Yes! Air going in a straight line is what you want. The problem is the
straight line of the spacer is not inline with the straight line of the
manifold and head port.
The point is that adding this spacer that clearly has the port milled
perpendicular to the face puts kinks in the flow.
The port in the manifold is inclined up 21 deg (dug out my paperwork and
found the actual number) from the head-to-block surface of the head. The
port in the head (at the manifold interface) is also inclined up at 21deg.
The centerline of the port in the spacer is parallel to the head surface. 21
deg difference.
So, the air comes down the manifold port at 21 deg does a quick jog to 0 deg
goes 3/8" then does another quick jog of 21 deg. This is not a straight
line.
Now to answer the next question. Can I just port the spacer to 21 deg??
No! Because the centerline of the manifold port and the head port will be
offset by 1/8". ~.375 X tan21. In this case there will be big
discontinueties in the port wall disrupting airflow even more. Try to
visualize a side view of the port.
Well, hell! While we're paying way to much attention to this POS. The whole
idea of this spacer is to insulate the intake manifold from the head so the
manifold is cooler and doesn't heat up the intake air. But, where is the
intake manifold picking up its heat from? If it's picking it up from the
head (bearing in mind that there is already an insulator/gasket between the
head and the manifold!) then insulating it would be a good idea. But, what
if it's picking up most of it's heat from the adjacent exhaust manifold? If
that's the case then this spacer won't do jack Personally, I think the
proximity to the exhaust manifold it the most likely source of intake
manifold heat.
I don't think I've told anyone on this list not to try something, but the
engineer in me says this is just a waste of time.
If you do before and after dyno runs, make sure engine and ambient air temps
are comparable and that the underhood environment is comparable i.e that the
effects of any potential intake manifold heating are the same.
Best of luck.
Dan
----- Original Message -----
From: Allyn <amalventano1@comcast.net>
To: Larry <rocco16v@netzero.com>; Dan Bubb <jdbubb@ix.netcom.com>;
<Scirocco-l@scirocco.org>; <flaatr@yahoo.com>
Sent: Saturday, March 02, 2002 1:00 PM
Subject: Re: What about the port? was: Do these things work?
> How is air going in a straight line a 'hiccup'? air wants to go in a
straight line... the more
> straight line the better.
> Al
>
> ----- Original Message -----
> From: "Larry" <rocco16v@netzero.com>
> To: "Dan Bubb" <jdbubb@ix.netcom.com>; <Scirocco-l@scirocco.org>;
<flaatr@yahoo.com>
> Sent: Saturday, March 02, 2002 8:19 AM
> Subject: Re: What about the port? was: Do these things work?
>
>
> > Good point, Dan.
> > If the angle is not "built-into" the spacer, this little hiccup in flow
may
> > offset any gains from reduced heat.
> > No free lunch, eh?
> >
> > Larry sandiego16V
> >
> > > Aside from the potential reduction in heat has anybody thought about
the
> > > port shape?
> > > The port exits from the head at ~23deg from perpendicular. So, putting
in
> > > this spacer gives you a short section perpendicular to the head and
> > offsets
> > > the axis of the manifold port from the head port by about 1/8".
> > > Significant?? I'd think it's a bigger factor than loosing a little
heat.
> > > Dan
> > >
> > > ----- Original Message -----
> > > From: Euroroc II <flaatr@yahoo.com>
> > > To: <Scirocco-l@scirocco.org>; <flaatr@yahoo.com>
> > > Sent: Friday, March 01, 2002 4:54 PM
> > > Subject: Do these things work?
> > >
> > >
> > > > Seems like a good idea and it makes sense like it should work but
does
> > it?
> > > >
> > > >
> > >
> >
http://cgi.ebay.com/ebaymotors/aw-cgi/ebayISAPI.dll?ViewItem&item=1809256474
> > > &r=0&t=0
> > > >
> > > > -Raffi
> > > > '84 Scirocco gone to a better place
> > > > '87 Scirocco 16V from Hell
> > > >
> > > >
> > > >
> > > > _________________________________________________________
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