Date: Sun, 9 Sep 2007 22:53:37 -0700
Reply-To: David Kao <dtkao0205@YAHOO.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: David Kao <dtkao0205@YAHOO.COM>
Subject: Re: cracked AMC heads question
In-Reply-To: <ed96608f0709092043m7c9789c0m2838a01913522c1b@mail.gmail.com>
Content-Type: text/plain; charset=iso-8859-1
It's really a question how well you want to rebuild your engine.
A crack between the valves may be fine for a while but eventually
the head will fall apart. You will have to take it apart again
to deal with it eventually.
If you want the engine back to what it was but with no crack on
the head to worry about then buy a used one that has no crack and no
damaged valves and valve seats. Just do a valve job and put the engine
back together. This may last a long time and the engine performance
will reflect its mileage.
But if you really want your engine rebuilt back to top performance
the best strategy is to spend for a pair of new heads. Replace the
piston/cylinder liners as well. If everything is done properly the
engine will perform well over another 100k without giving you performance
issues.
I just had my 1.9 engine rebuilt. I put in a new set of liners only because
the heads were replaced 20k miles ago by a VW dealer under warranty. I first
thought the heads were rebuilt. But I found out that the heads were actually
new VW heads. After 3k miles of break-in I am extremely happy with the result
of the rebuild. The engine is totally cool now. I am glad that I had the
new liners in it.
An 87 Westy is worth a full restore if I were you. Good luck.
David
--- Chris Lisica <wavanagon@GMAIL.COM> wrote:
> Yeah, sorry, I'm talking about the cracks between the valves. I've heard
> that a hairline fracture is acceptable, but that one in my picture is pretty
> big. A leak test would be good.
>
> Hmmm, thanks for the advice. Some of those measurement numbers are scary! I
> have a line on a used set of German heads for $200, I may just go that
> route.
>
> Chris
>
> On 9/9/07, Scott Daniel - Shazam <scottdaniel@turbovans.com> wrote:
> >
> > You're talking about the cracks between the two valves ?
> > Totally normal.
> > You 'could' get them pressure tested if you're worried,
> > You can also peen the cracks shut with a hammer and punch.
> >
> > Fwiw - ..judging by the corrosion where the water gasket touches this head
> > -
> > perhaps you might get away with head gaskets only.
> >
> > I would also test for valve sealing by filling the ports with gasoline or
> > kerosene, and see if they leak. I usually find at least one exhaust valve
> > leaking.
> > Then I have a machine shop do a valve job.
> >
> > And what I wanted to say about AMC heads - fwiw, I have one.....that I
> > installed new, and it didn't last, for head gasket sealing .....that
> > particular head is so far out of 'dimension' it's sick. Pure
> > junk. And
> > it was factory new. So I'd be careful about AMC heads, if nothing else.
> >
> > I'm finding it necessary to check how much the water gasket gets
> > compressed.
> > By my measurements the water gasket is 3.7 mm thick.
> > Put the head on temporarily ( with metal sealing rings at the top of the
> > barrels ) and measure the water gasket gap.
> > Iv'e seen it be 3.7 mm - thus no compression on the water gasket - and it
> > leaked after a thousand miles.
> > Iv'e seen it vary , like 4 mm on one end, 7 mm on the other, and so forth.
> > And I'd be real careful with AMC heads.
> > I'd rather have a good set of used non-amc heads and rebuild them, then
> > install them, than use AMC heads, unless the measure out nicely.
> > Scott
> > www.turbovans.com
> >
> > -----Original Message-----
> > From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> > Chris Lisica
> > Sent: Sunday, September 09, 2007 7:35 PM
> > To: vanagon@GERRY.VANAGON.COM
> > Subject: cracked AMC heads question
> >
> > Volks,
> >
> > After purchasing my wife's 87 Westy project, I'm finally getting started.
> > I
> > knew the heads were messed up, but I was hoping for a simple head gasket
> > job. Upon closer inspection, and a few pictures in macro focus mode, there
> > appears to be a big crack on the one side. Any opinions? Is this head
> > reusable? What could cause such a large crack? The pics:
> >
> > http://wavanagon.googlepages.com/amcheads
> >
> > Please help enlighten an aspiring Vanagon mechanic. Thanks for any
> > advice/input/feedback/links/etc.....
> >
> > --
> > Chris
> > 88 Vanagon GL (daily driver)
> > 87 Westfalia (in progress)
> >
> >
>
>
> --
> Chris
> 88 Vanagon GL (daily driver)
> 87 Westfalia (in progress)
>
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