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

[chris chambers]

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
> 
> 
> 
> 
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