3B and AAN/ABYADU differences - need input

[saltinot]

Cam sprocket is different on a 3B than AAN/ABY. ADU gear is exclusive to ADU engine.

[UrS4boy]

Cam sprocket is different on a 3B than AAN/ABY. ADU gear is exclusive to ADU engine.

Yep. Need to add that info. Thanks Tom.

3B, RR (and NM and 7A) = 034109111
AAN and ABY = 034109105
ADU = 034109105B

[UrS4boy]

I am told that originally the 3B rods were something like 80 grams heavier than the ADU rod. Here is a photo that supposedly has a 3B rod on the left and an AAN rod on the right. Anybody with old PNs for these?

[SteveH]

I am told that originally the 3B rods were something like 80 grams heavier than the ADU rod. Here is a photo that supposedly has a 3B rod on the left and an AAN rod on the right. Anybody with old PNs for these?

The rod on the left is definately a 3B rod. Matches the one i have left from my engine before it was slightly deformed

rod 002.jpg

[Error404]

Won't you be surprised! (still a work in progress)

yes I am a bit I thought the ABY / ADU had slightly higher compression

The ABY / ADU and later AAN head is different to the 3B (think hall sender boss )

[Jamo]

Compression difference was due to the paper gasket but the metal gasket is now standard so really isn't a factor anymore

[UrS4boy]

yes I am a bit I thought the ABY / ADU had slightly higher compression The ABY / ADU and later AAN head is different to the 3B (think hall sender boss )

You are right about the head. That whole exercise is useless because the PNs that I picked up are what is available in the system NOW, not back in the day. NOW an AAN head works on a 3B or an RR (or ABY or ADU). But back in the day, the 3B head did not work as a later AAN head because, as you said, the cam position boss would be missing (there are solutions to fix that). Oh well, it only took an hour to do.

[UrS4boy]

Yep. Need to add that info. Thanks Tom. 3B, RR (and NM and 7A) = 034109111 , AAN and ABY = 034109105, ADU = 034109105B

Not that it matters but to be more complete:

[Colesy]

So a 3b head wouldn't be a straight swap into an ABY then?

What are the solutions for the cam position boss?

[4WheelDrifter]

Did you want to mention the block and timing belt tensioner differences?

So a 3b head wouldn't be a straight swap into an ABY then?

What are the solutions for the cam position boss?

Make your own?

[Colesy]

Did you want to mention the block and timing belt tensioner differences?


Make your own?

Ahh I see, that looks a bit beyond my skill set!

Is this something MRC might be able to hep with or can anyone recommend someone else who's done this before?

[UrS4boy]

Some 3B 200 20vt and S2 Coupe info

3B and AAN similarities and differences
3B Engine Cut-away:

3B Engine With Labels:

3B in 200 20VT Ghosted:

S2 Coupe ghosted:

3B distributor:

Distributor supercedence:

3B and ABT turbo to intake hoses:

3B ECU pin-out:

3B ECU schematic:

3B 200 20vt diagnostic plugs:

3B PCV system:

3B WGFV:

3B and ABY Oil Pressure switches:

3B Fuel Pressure Regulator:

3B MFTS info:

3B and AAN timing belts:

3B Ignition Coil Info:

3B radiator location:

3B coupe exhaust:

[s2driveruk]

downpipe and cats are 3b specific if not already captured

[UrS4boy]

OE 3B, AAN, ABY and ADU Exhaust Components: a consolidation of info.

downpipe and cats are 3b specific if not already captured

I did say *Some*, i.e. not all.

Anyway, I went to my consolidated exhaust post and posted a 3B exhaust component diagram above.

OE 3B, AAN, ABY and ADU Exhaust Components: a consolidation of info:

http://forums.quattroworld.com/s4s6/msgs/196904.phtml

[s2driveruk]

are you looking at the ancillaries too like alternator, AC compressor, etc