Date:         Wed, 23 Apr 2008 18:48:00 -0400
Reply-To:     pickle vanagon <greenvanagon@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         pickle vanagon <greenvanagon@GMAIL.COM>
Subject:      Thoughts on Cracks between Valves on Heads?
Content-Type: text/plain; charset=ISO-8859-1

So...
I'm planning on doing the heads on my van.  I ordered the head gasket kit
from Van-again, and Ken sent his instructions which look very good and
thorough.

Because I cannot afford new heads, I bought a pair of "very lightly used
heads" at roughly 1/3 the price of new AMC heads.  The heads came off the
seller's friends van after a rebuilt engine threw a rod (bummer), and should
be practically new (say, less than 1500 miles).

The heads came today, and indeed, looked beautiful, at least to me.  They
looked like they had been run for a few hours and taken back off.  Anyways,
after cleaning the area between the valves with brake cleaner, however, I
discovered the famous cracks between the valves.

Interestingly enough, the heads are one AMC head, one VW head.  Both have
the cracks (The AMC head between both pairs of valves, the VW head between
just one of the pairs).  There are no cracks in either going to the spark
plug hole.

Page 15.17 of my Bentley has this note in the upper left corner:
"Cylinder heads with cracks between valve seats or between a valve seat and
a spark plug thread can be used again without reducing service life provided
that the cracks are not more than 0.5mm (0.019 in) wide or that only the
first coil of plug thread is cracked."

On the other hand, I am sure that there are many with the opinion that any
cracks at all indicate impending failure.

In my case, the cracks are at most 0.1mm (none can be seen without some sort
of magnification).  And I believe the seller that they are as new as he says
(and the rest of their condition seems to indicate this).

I'm wondering: has anybody installed new heads (VW or AMC), and them pulled
them later, steam cleaned them, put them under a magnifying lens, and found
no cracks between the valves?  Or is it likely that these cracks basically
always show up in the first few thousand miles, and VW is correct in saying
that their presence alone doesn't indicate a significant shortening in life?

In any case, I plan on getting the heads pressure tested tomorrow, but I
expect that they will pass. Assuming they do, who thinks I should expect
these heads to last for less time than (really) new ones?

Thanks very much for any thoughts.
-Wes