[s-cars] CPS mounting boss changes in early 92 - 93 AANs

[Ben Swann]

Dave,

I can't answer your question, but do happen to have a version of the head you describe.
This supposedly RS2 head differs from the AAN head in that there is no mounting boss for
the Cam Position Sensor as on the AAN head.  I have both side by side.  The distributor
port is blocked off with a circular cutout, but I don't see how either distributor or
front mounted hall would have been used. I think this Ear;u RS2" head is the same or
similar as the one you have shown with the CPS boss - where do I get one of these?  I
see you mention it below - contact info?

I don't know if I can even use a distributor with the RS2 intake manifold or not -
haven't tried.  Tuna can?  Is that like an abbriviated distributor with hall pickup only
in it?  More info. please as I am looking for alternatives for this head.

Ben

[Date: Wed, 30 Jul 2008 11:07:59 -0700
From: David Forgie <forgied at shaw.ca>
Subject: [s-cars] CPS mounting boss changes in early 92 - 93 AANs
To: s-car-list <s-car-list at audifans.com>
Message-ID: <cfb6d7695b2e3.48904b8f at shaw.ca>
Content-Type: text/plain; charset=iso-8859-1

As you know, the cam position sensor (Hall sender) on the AAN engine is typically
mounted on the head, behind the exhaust cam sprocket.? Exceptions are the very early
AAN's that used a vestigial (tuna can) "distributor" at the back side (intake side of
the engine), driven off a gear on end of the intake cam. That was a carry-over from the
7A and 3B engines (which had full distributors).

Up until yesterday, I always thought that when the CPS moved from the tuna can, to
behind the cam sprocket, the mounting boss was cast into the head.? NOT so.? There is
evidence (as shown in the link below) that the factory used up some 3B heads by
supplying a separate mounting boss that was bolted to the head (and then the CPS was
bolted to it).? I am curious as to when this practise started and stopped, based on
build date.? So if you have such a non-cast boss, can you please post your car's build
date?? (Thanks).

Photo of the add-on CPS boss (note - no PN in the FA for this):

http://forums.audiworld.com/s4s6/msgs/231574.phtml

Here is a photo of the "normal" cast CPS-mounting boss:

http://forums.audiworld.com/s4s6/msgs/231588.phtml

This all came up because a fellow in Norway has developed an add-on boss that will
permit 7A heads to be used with normal AAN CPSs.

Dave F. ]