Re: Head Porting

[DeWitt Harrison <de@aztek-eng.com>]

On Tue, 20 Jul 1999 02:09:46 EDT, Javad Shadzi wrote:

>In a message dated 7/20/99 1:24:48 AM Eastern Daylight Time, 
>phen9461@uidaho.edu writes:
>
><< Hmmm,
> 	Well, it doesnt seem deep.  Maybe its fine.  It is visible to the
> naked eye though.  Who knows if I have more that aren't.
> 	Thanks for the input.
> L8R
>  >>
>	My machinist said that unless it goes all the way through, not to 
>worry about it.  Audi/VW heads are very prone to cracking because there is so 
>little material between the valve seats.  Often, the cracks are only in the 
>material between the seats and quite superficial...

Generally true. The Bentley even attempts to define the acceptable
maximum crack size.  However, if your machinist happens to get a
touch heavy handed with the die grinder and/or you use the engine
pretty hard, those tiny cracks can definitely become large enough
to find water. btdt. I would be tempted to have the valve seats
yanked and the cracks welded before putting any other money into
it. But for a purely stock application, I bow to the consensus.

DeWitt Harrison
Boulder, CO
88 5kcstq