AAN head Question

[Cor80]

Hi Everybody

I have an urS6 that seemed to have a tendency to leak a little water into the oil...but only when boosting, not under normal driving...
So I took the head off and had it pressure tested and the engineering company came back and said there is a crack between the spark plug and valve that causes the leaking...they found that with the initial pressure test nothing leaked, but after a "hot" pressure test was done it leaked.

Obviously I now try any source a replacement head (AAN or 7A) but it seems that all good heads has gone to a secret island where nobody will find them.

When asking the engineering guy about welding up the crack they seemed hesitant. According to them this rarely works, or works in the long term...

Is welding up the crack out of the question and/or as futile as it is made out to be?

Any comments or advise would be appreciated, thanks.

[macspring]

Maybe ask JP at JNL Racing to source and modify a 7A head for use on the AAN ?

or source one yourself in the UK and have it sent direcetly to him to modify and send onto you.

Not the cheapest option given your location, but one of the best options / end result long after the cost is 'forgotten'.

Best wishes.

[UrS4boy]

AAN (And ABY and ADU) Spark Plug Area Cracks

Common to have small cracks at the spark plug threads. Okay if not too big.





Here is a crack in that area and it never made it to a coolant passage.



On page C 15-1 of Volume 1 of the three volume Bentley hard copy, regarding cracks around the spark plug threads, they say:

"Cylinder heads with cracks between the valve seats or between the valve seat and spark plug threads may be reused without reducing service life, provided cracks do not exceed 0.5 mm (0.020 in) width or when no more than the first threads are cracked".

This same info is on page 39/93 of the AAN pdf that is available for download from the website below (download, save and open):

http://www.s2-audi.co.uk/workshop/aan/aan.pdf

[Cor80]

Thanks for all the replies,

I'm currently considering a 7A to AAN head conversion but I have a question on that.

Apart for the machining of the water port ans sensor...what else is required. Can I still use my AAN valve cover and coil packs?

[diesel des]

Can sensor boss required. Talk to jp.

Sent from my LG-H955 using Tapatalk

[UrS4boy]

AAN G40 Camshaft position (Hall effects) sender mounting transitions.

Can sensor boss required. Talk to jp.

Something like this:

Factory version (when they used some early AAN tuna-can heads for the 2nd location of the G40 Cam Sensor):



Aftermarket:



REFERENCE:

AAN G40 Camshaft position (Hall effects) sender mounting transitions:

http://forums.quattroworld.com/s4s6/msgs/121024.phtml

[varia]

this is JP version:

https://www.flickr.com/photos/quattr...7664281026059/


https://www.flickr.com/photos/quattr...7664281026059/
https://www.flickr.com/photos/quattr...7664281026059/

[UrS4boy]

this is JP version:

Chris: Can I steal a couple of those JP mount photos for my G40 cam sensor info post? (Credit to you)

[varia]

Chris: Can I steal a couple of those JP mount photos for my G40 cam sensor info post? (Credit to you)

yes, of course. But credit it to JP, he made them

[UrS4boy]

yes, of course. But credit it to JP, he made them

I am not sure who JP is.

The one photo will be the clearance between the cam shutter wheel and the G40 itself.

[varia]

JP = JP Jnl Schoonbrood at JNL Racing
the guy with the ugly and slow s6 he made those brackets.

I just made a template (alien face) and welded on my head.

[Quattronaut]

Concersion from 7A to AAN is best option. It is not too hard to do and not too expensive.

The welding thing is much more tricky- the exact material of these old heads is not always the same, it is not documented or defined that accurate, so when the crack is welded, the welding spot is always another material, and then it will crack again over the time.

[Cor80]

Concersion from 7A to AAN is best option. It is not too hard to do and not too expensive.

The welding thing is much more tricky- the exact material of these old heads is not always the same, it is not documented or defined that accurate, so when the crack is welded, the welding spot is always another material, and then it will crack again over the time.

Thanks,

I'm currently trying to find a decent AAN or 7A head to replace it.

[orignalS60]

^^Contact JP as he has cores for
all of his offered services. Great guy
to deal with. Finding a core and then
shipping it to the UK or US for the
water manifold machining will add
up quick.

[macspring]

^^Contact JP as he has cores for
all of his offered services. Great guy
to deal with. Finding a core and then
shipping it to the UK or US for the
water manifold machining will add
up quick.

Agreed.