Date:         Thu, 11 Dec 1997 23:16:10 -0800
Reply-To:     Malcolm Holser <mholser@ADOBE.COM>
Sender:       Vanagon Mailing List <Vanagon@Gerry.SDSC.EDU>
From:         Malcolm Holser <mholser@ADOBE.COM>
Subject:      Re: Conversion Commotion
Comments: To: jscohen@SPRYNET.COM

> And finally, Subaru fixed the head problem?  I've heard this before. WILL
> SOMEONE PLEASE TELL ME HOW?  WHAT DID THEY DO? I have YET to get an answer
> on this.
>
> James
>
> PS, when the heads start to leak, is the fix simply to replace the head gasket?
>
well, Jimbo, VW really pulled a boner on this design.  Basically they took
the old air-cooled engine and surrounded the steel cylinders with water
jackets.  Old VW engines never used real head gaskets, although the later
ones use a metal "sealing ring" on the top of each cylinder. There is a
lot of differential expansion between the steel cylinders and the aluminum
case/water jacket, so there is a big gap at the head end, and this is
filled by a rubber sealing gasket.  The cylinders are wedged between the
lower case and the stepped insides of the head, just like the air-cooled
one.  I doubt they leak very often there.  VW has always had troubles with
the engine studs loosening over time -- it is common on air-boxers to find
loose head nuts (there are almost *always* a few).  I don't know if this is
a problem on the waterboxers, but the bolts are easier to get to without all
the tin shrouding, so keeping them tight should be easier.  Maybe I'll
check mine someday.

Nobody designs heads like this.

Subaru did what everybody else does -- the cylinders are sleeves pressed
into the aluminum block, and the normal composite head gasket fits between
the flat engine top and the flat head bottom.  The Subaru engine really is
two two-cylinder standard engines bolted together.

No magic there.  I sure hope that Porsche did a better job on the boxster,
and the Continental did a better job on the water-cooled 540 (an airplane
engine).  It's hard to do worse than VW.  The other problem was that the
engine was used in a relatively rare (for VW) vehicle with a production of
only 4 years.  I guess it was not worth fixing the design.

Is the fix simply to replace the gasket?  There really is no fix, and the
majority seem to find the corrosion so bad on this seal area that a good
seal is difficult to obtain.  New heads will simply repeat the pain down
the road

malcolm