[s-cars] Are all Audi AAN heads cracked?

Mon Oct 5 22:03:26 PDT 2009

Hello all and thanks for the input. So in my quest for the white whale aka "crackless head" I have decided to cut my losses and begin the rebuild with a head that I am comfortable with (this meaning the head with the fewest and smallest cracks within spec) So in this quest i have definately learned 2 absolute truths:

1. That a perfect AAN 20vt head is quite the "unicorn" and should be on exhibit in the smithsonian.

2. That Audi is very proud of their 20vt AAN head, seeing that a new one would set you back almost $3k.

I appreciate the post re: the Bentley manual and the crack allowance specs for the 5000. I believe it was 0.5mm (.020in). So at this point one must take inventory and realize that after having invested so much into a project (both time and money) that it would be nice to have the car on the road and enjoy it once again after being parked for almost 2 months. 

Joel M. Phillips MS, OTR/L, CEORenaissance Rehabilitation AssociatesMobile: 269-377-5594
Fax: 1-866-594-4367

Date: Mon, 5 Oct 2009 07:36:57 -0700
From: fastscirocco_2000 at yahoo.com
Subject: Re: [s-cars] Are all Audi AAN heads cracked?
To: qweblog at gmail.com
CC: cody at 5000tq.com; Vittorio.Bares at nuance.com; s-car-list at audifans.com; joelmphillips at hotmail.com

Brian,

Thanks for the input, all info helps! I don't know the size of the cracks in question, could it be the machine shop is "too" picky?
I've not bneen in a situation where I've had to deal with a cracked head yet, but I'm afraid as these cars age and the miles continue
to pile on that more of us are going to have to face this issue...  ;-(

I'm sorry if he didn't reply to your email, rest assured Joel isn't a slacker, far from it in fact. 
The frustration lies in that so far he has purchased 2 heads (advertised as no cracks), only to discover they were both cracked.
Now I'm not saying he didn't reply to one of your emails due to whatever reason....that happens to everyone now and again.

I'll get your message to him, I'm sure he'll be in contact.

Thanks again
Chris

From: brian hoeft <qweblog at gmail.com>
To: chris chambers <fastscirocco_2000 at yahoo.com>
Cc: Cody Forbes <cody at 5000tq.com>; "Bares, Vittorio" <Vittorio.Bares at nuance.com>; Scar <s-car-list at audifans.com>; Joel Phillips <joelmphillips at hotmail.com>
Sent: Mon, October 5, 2009 10:09:39 AM
Subject: Re: [s-cars] Are all Audi AAN heads cracked?

in my experience the problem is more pronouonced in 10v motors and its not a big deal so long gas the cracks are only slight and between the valve seats & not leaking.. heard of shops welding the cracks and heard of folks not fixing cracks, then boosting the same w/o harm.. myself being one, with a stage 3 audi 5k, sold running strong with ?380k miles... till a tree fell on it..

PS your friend probably isnt searching hard enough.. my email sent to an audifans post of a good AAN head wasnt returned. 

no empathy for slackers, -brian

On Thu, Oct 1, 2009 at 5:52 PM, chris chambers <fastscirocco_2000 at yahoo.com> wrote:

Gentz,

back onto the cracked head topic....

Is it ever acceptable to have cracks in an AAN head when using the head for
higher than stock horsepower? Is there a guide on acceptable cracks?

Joel has been hunting for a replacement head for his S6 and heads that were
described to be guaranteed crack-free have multiple cracks.

I and Joel would welcome your informed input!

Thanks
Chris

----- Original Message ----
> From: Cody Forbes <cody at 5000tq.com>
> To: "Bares, Vittorio" <Vittorio.Bares at nuance.com>; chris chambers <fastscirocco_2000 at yahoo.com>; Scar <s-car-list at audifans.com>
> Sent: Wed, September 23, 2009 12:25:28 PM
> Subject: Re: [s-cars] Are all Audi AAN heads cracked?
>

> My experiance on the matter is with 10v heads. I'd bet it's a simmilar
> situation. For the 10v heads Audi supplies a spec for cracks.
>
> From the 5000tq Bentley "Cylinder heads with cracks between the valve seats or
> between the valve seat and the threads of the spark plug holes can be reused and
> resurfaced without reducing the service life if the crack(s) do not exceed a
> width of 0.5mm (.020in)."
>
> -Cody Forbes
>
> ----- Original Message ----- From: "Bares, Vittorio"
> To: "chris chambers" ; "Scar"

>
> Sent: Wednesday, September 23, 2009 8:08 AM
> Subject: Re: [s-cars] Are all Audi AAN heads cracked?
>
>
> I just changed the HG on my AAN head. My head has cracks - and I've been told by
> this list as well as on Motorgeek that this is just the way it is. We live with
> it - apparently without adverse effects. I replaced my head with one that had no
> cracks - I just happened to come into one through a series of events.
>
> I will say that the machine shop was not comfortable with the cracks.
>
> Vittorio -
> -----Original Message-----
> From: s-car-list-bounces at audifans.com [mailto:s-car-list-bounces at audifans.com]
> On Behalf Of chris chambers
> Sent: Wednesday, September 23, 2009 8:02 AM
> To: Scar
> Subject: [s-cars] Are all Audi AAN heads cracked?
>
> Gentz,
>
> I have a friend searching for a good uncracked AAN head.
> He just found out that the head he had purchased that was described as havin
> been
> rebuilt ~10,000 miles; has cracks in all 5 cylinders, with multiple cracks in
> 2,3 & 5.
>
> So my questions are:
>
> 1. Do all of these AAN heads have cracks and we simply live with them or is he
> just having a hard time?
>
> 2.I have an unmolested stock engine (car wasn't chipped) that runs well, if I
> pull the head off that for him
> is it likely that I will discover it has cracks in it's head.
>
> 3. What is the best way to check a running engine for cracks in the head?
>
>
> Regards
> Chris
>
>
>
>
> _______________________________________________
> S-CAR-List mailing list
> http://audifans.com/mailman/listinfo/s-car-list
> http://www.audifans.com/kb/List_information
> _______________________________________________
> S-CAR-List mailing list
> http://audifans.com/mailman/listinfo/s-car-list
> http://www.audifans.com/kb/List_information

_______________________________________________
S-CAR-List mailing list
http://audifans.com/mailman/listinfo/s-car-list
http://www.audifans.com/kb/List_information

-- 
http://208.53.138.125:8068/
[blinders off&earplugs out]

_________________________________________________________________
Hotmail: Trusted email with Microsoft’s powerful SPAM protection.
http://clk.atdmt.com/GBL/go/177141664/direct/01/