AAN & ABY specific differences

[20vQC]

ooook! hehe I have the late one then!thanks for the pic spink!

[S2central.net]

According to illustration 905-20 for an MY92 A100Q the hall sender on the head comes into effect from 4A-N-100-001

But dammit I have seen the engine number for this crossover somewhere else... Looking now.

Memory is a strange thing

I was about to reply to this thread with a comment that the early AAN engine as the same inlet camshaft as the 3B engine (cos it has the gear needed to drive the dissy) whilst later AANs have same inlet cam as the ABY engine (no gear required for dissy)...

And thats when I remembered where I'd seen the engine number for the crossover on the AAN engine ---->

A10Q-92-1-09 (Ill 109-22) clearly shows the early cam as up to AAN003910 (aligning up to VIN 4A-N-100-000) with inlet cam 034 109 021 AQ (which I've also crosschecked as correct for 3B on the S2 from 8B-N-005-501)

whilst we have 034 109 021 AN starting at AAN003911 from VIN 4A-N-100-001. This camshaft is common to ABY and ADU engine.

Smoking gun attached... Job done or what !!!!

[S2central.net]

Just to finish the family album fun - AAN003911 dates to January 1992 whilst the VIN 4A-N-100-001 dates to Feb 1992 so that all makes sense.

If anyone can get the exact date for this monumentous occasion there should be a prize


Paul

[Error404]

I'll donate a pie to the winner!

[20vQC]

there's mine!

[UrS4boy]

Just to finish the family album fun - AAN003911 dates to January 1992 whilst the VIN 4A-N-100-001 dates to Feb 1992 so that all makes sense.

If anyone can get the exact date for this monumentous occasion there should be a prize Paul

Well, I probably could if that lovely VIN decoder in Romania hadn't died. It had the build date down to the week. B*gger.

However, based on a "Monster Survey" of UrS4 and S6s I did with "lskolnick" on AudiWorld in 2004, we came up with this info:

"A forum member with a hall sender in a tuna can on his AAN, provided me with the last six numbers of his NN VIN code. I sorted the Monster Survey results (that Skolnick and I did in early 2004) and got the following data (by car type, model year, body type, month of build, year of build, VIN):

S4 1992 Sedan 2 1992 NN94310
S4 1992 Sedan 2 1992 NN96417
S4 1992 Sedan 2 1992 NN97586
S4 1992 Avant 3 1992 NN96901

The forum member's numbers were in the middle of that group so, I am guessing that his car is a 2/92 car and maybe mid-to-late February, 1992 car. We also captured three 1991 build-date cars in the survey. The earliest one was Aug.91; Skolnick's ZZZ car is 11/91."

So, I think sometime in mid-February was the likely change over to the G40 Cam Position Sensor behind the cam sprocket. Note: for bonus points, it appears that even after the change, they continued to use modified 3B heads since the factory supplied mounting bosses for the CPS to mount to the 3B head. (Which a forum member here from Norway (IIRC) is now reproducing). Now when they stopped doing that (using up 3B heads and going to real AAN heads with cast CPS mounting bosses, I doubt that we will know - but hey, the data *might* be in ETKA (somewhere). (There is no PN for the separate factory boss AFAIK).

Dave F.

[S2central.net]

Oh fantastic - who is making the boss/bracket that bolts onto a 3B head to fit the CMP under the cam pulley ?

I assume that will work with a 7A head just the same - brilliant if it does - one less job to fret over

[20vQC]

As I broke my Hall on my aan, I have contacted my spares dealer but he couldn't find any BOSCH sensor with that code, he told me was discontinued by bosch... So I had another homework to do, it was, take the pulley from my NM(7A), drill a hole where a little plate of 18mm was bolted in, then... on the head, make a plate that was attached to the engine head in the lace where the OEM sensor was, then connectd two other plates and the new hall sensor (hyundai spare number), check the TDC pin on the flywheel.. and finally put the two signals of the HALL and the one from the TDC.. come at the same time. Sounds to be easy... but was a hell!!!!

[S2central.net]

Been looking at the family album again... The head 034 103 351 N is common across the 3B/AAN/ABY/ADU and even the mighty KW (S1 Engine)

The engines with the CMP at the cam pulley call out a 6M6x16 dowel pin (N 013 210 2) which I presume locates CMP bracket - which I also must presume bolts into the head on an existing hole.

I can find absolutely no reference to any CMP bracket - other than what forms part of the CMP itself. This is 034905161 and I cannot find an earlier variant of it. Most peculiar.

Afternote - Head 034 103 351 B is for the NM & 7A - there was other part numbers superseded by that on early engines.

[Error404]

i'm confused now!
How can that head be common to the NM/7A as well as the 20vt engines, regardless of the CMP bracket without the holes for the water rail?

[UrS4boy]

Oh fantastic - who is making the boss/bracket that bolts onto a 3B head to fit the CMP under the cam pulley ? I assume that will work with a 7A head just the same - brilliant if it does - one less job to fret over

Paul: You must have been snoozing and missed the thread. The bracket maker is forum member "Bruno" (Rune) from Norway. He linked out to the bracket:

http://forum.vwaudi-club.no/showthread.php?t=127954

in this S2 forum thread:

http://www.s2forum.com/forum/showthread.php?t=27092

Here is a reply to my announcement about Bruno's bracket on Audiworld, showing the factory version that was used on some early AAN heads (the part that "never existed"):

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

Dave F.

[S2central.net]

i'm confused now!
How can that head be common to the NM/7A as well as the 20vt engines, regardless of the CMP bracket without the holes for the water rail?

Yer right - I had a wee brain fart there earlier... I have edited the previous post
NM & 7A indeed has differnt head.

[S2central.net]

Dave - I certainly did miss this one... I'll have to investigate further then.

Cheers,

Paul

Paul: You must have been snoozing and missed the thread. The bracket maker is forum member "Bruno" (Rune) from Norway. He linked out to the bracket:

http://forum.vwaudi-club.no/showthread.php?t=127954

in this S2 forum thread:

http://www.s2forum.com/forum/showthread.php?t=27092

Here is a reply to my announcement about Bruno's bracket on Audiworld, showing the factory version that was used on some early AAN heads (the part that "never existed"):

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

Dave F.

[gedu]

Oh, I can pitch in, that they got "true" AAN head in MY 1992. My car came out in may (15th I think it was) 1992, and has not "part that never existed".

[4WheelDrifter]

Been looking at the family album again... The head 034 103 351 N is common across the 3B/AAN/ABY/ADU and even the mighty KW (S1 Engine)

I think you mean RR not KW. The Sport quattro used a different head.