20V head questions

[JShadzi at aol.com]

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[ Picked text/plain from multipart/alternative ]
Valve sizes are all the same, the only real difference is the water jacket,
the 20vt cars all have through ports to the drivers side of the car to allow
better cooling of the combustion chambers.  The 7A head can be modified to do
this by drilling some 1/4" NPT holes or so, or with some careful machining,
the factory water manifold could be used.  This isn't critical, but does add
a good measure of detonation resistance to the motor, in turbo applications,
those combustions chambers can use all the cooling they can get.

Javad

In a message dated 7/2/2002 1:27:52 AM Pacific Daylight Time,
billzcat1 at hotmail.com writes:


> Just wondering if there are any significant differences in head design
> between the 20v N/A head and the 20v turbo head....obviously they will use
> different cams and some 20vt heads (AAN) will not have provision for a
> distributor.  Looking for thoughts on valve size/construction, head volume.
> For the record, I know the 20v N/A head has sodium filled exhaust valves,
> I'm assuming the 20vt heads do as well...but are they smaller to enhance
> durability?  I imagine the 20vt heads have a larger valve seat/smaller
> ports
> as well; Again to help thermal conductivity/durability.
> Any thoughts?
> Thanks in advance,
> Richard
> 1990 CQ 203K up late asking silly questions
>