Date:         Tue, 4 Mar 1997 18:16:01 +0000
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         vwbus@netbiz.net
Subject:      NEW T4 Heads (was: where to buy valve tools)

> for the typeIV 2 litre engine, new heads from JC whitney are $350.00 each,
> $700.00 total. Mark Stephens heads are $500.00 each, $1k total, core
> required. (secondhand information from a friend with an 80 westy.)  this
> made the idea of purchasing an extra set of heads somewhat costly.

And to boot, the "new" AMC Spanish heads (AMC is cast on bottom of 
rocker box) are a bad idea in stock form.  This is the story as 
Stephens tells it, apparently AMC bought the factory tooling to cast 
these heads, fairly obvious as I have both sitting here and they are 
exact copies save for the removal of the VW part numbers from the 
inside of the rocker box.  Well as the VW heads have tendancy to 
crack, particularly at spark plug to valve seat area, AMC thought 
they would do better and used a different and more elastic aluminum 
alloy.  Thing is the new alloy also has a higher coefficient of 
thermal expansion and they cut the seats with the same VW tooling and 
used the same VW seats.  The .005" or so (installed at temperature) 
interference fit sufficient for the VW heads is not enough for the 
AMC heads which pound their seats out in record time (like less than 
5k miles for the PO of my '81 though admittedly he was missing a good 
bit of tin).  The thing is this, they NEVER crack, so are the ideal 
head for a Stephens rebuild (hi-po even better) where they install 
the seats at triple the interference of the stock AMC installation, 
makes the perfect head.  I also note AMC heads have a built in .020" 
additional deck height for lower compression.  Anyway the point is 
Stephens has experienced poor luck (less than 50k) out of stock AMC 
heads but their quality rebuild on your stock heads are only $175, 
for a 5yr/100000 mile warranty (assuming of course they stay in 
business) make good $ense to me.  Also a good idea to seek out a core 
set of the AMC heads if you ever run across them.  They will rebuild 
them with 44 x 36 valves to whatever combustion chamber volume you 
want for something under $350 each if you want to try their "zero 
deck (.035" deck height)" solution for more performance.

John
vwbus@netbiz.net