Date: Mon, 24 Mar 2008 21:29:58 -0700
Reply-To: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Subject: Re: exhaust gasket question 2.1
In-Reply-To: <005901c88e28$25b98390$0201a8c0@MASTERPC>
Content-Type: text/plain; charset="us-ascii"
Hi Dennis,
Good to read your comments.
And if you've gotten that length of time or miles of use out of wbxe heads -
great ! I assume frequent coolant changes.
Replacable barrels are not that big a deal. Renoult and Citroen, to name
just tw inline 4 water ccoled 4 engines have had replaceable barrels for
years. On some of them........you can even replace the pistons and barrels
without dropping the pan !
As for cast iron blocks that can take a re-bore - that's been traditional
for years and years. Just bore it out to the next size, match the new
oversize pistons to the bore - almost as good as factory new.
Well, it's is funny how easily vw owners justify and defend how frequently
( though you say 21 years without doing head gaskets ) VW engines -
especially air-cooled ones and waterboxers need repairs.
If it was Toyota or Honda no one would tolerate it.
And the water boxer head gasket sealing system is a joke, and can not really
work that well, your 21 years notwithstanding.
For one, there is barely any way to keep exhaust gases from getting to the
coolant. There are the metal rings at the top of the barrel to contain that
pressure. They probably seal much better from new. I have had that surface
re-done by a machine shop, and the occresponding amount removed from the
large flat surface where the 'water retention ' rubber gaskets go, to good
affect. But.......the sealing there is mickey mouse.
The next 'seal' is the green o-rings. They get hard,, stuck, and even
brittle after a number of years.
And that out water gasket........look..........there is not ONE OTHER car
engine that has a 'rubber water gasket' on the cylinder head. Not one.
They ALL have a nice flat bottom to the head, and they use a 'real'
headgasket made of layers of tough material, or in some cases a few layers
of very thing steel under huge pressure ( wbxr head nuts are only 25 ft.
lbs torque) - like 'normal engine' head bolt torque is 80 lbs or so.
Or torque to yield stretch bolts.......that in any case, clamp a flat
bottom head down on to a solid block ( subaru is an opposed 4 water cooled
engine - and they did it right ) ......infenitely better sealing
And ........this REALLY GETS ME - how far the water retainging rubber gasket
gets compressed - it is adjustable by machining .....buy the 'step
distance' between there the metal rings sit in the combutstion chamnber and
the flat water gasket surface - but not many machine shops do this, and the
spec is not in the Bentley manual, and new heads are not a guareanteed it's
gong to be right..........PLUS.....how the barrels seat in the block is a
factor in how the water gasket is compressed.
I've seen them so they don't comnpress it enough, to where they compress
it too much, and the gasket pinches after a while, and there the head does
not even sit parallel to the top of the block where the water gaskets sit.
So.......given that..........how michky mounse and variable that distance
is.......it's almost 'random' .......and that there is a RUMBBER GASET there
where no other manufacturer anywhere would never do such a thing .........
Well, I think you get my point.
If you've worked on engines from 40 or more different manufacturers and
notice that no one else does anything this silly........you might agree.
I run them and operate them and keep up with them.
But I admire Subaru engines massively !
Scott
www.turbovans.com
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Dennis Haynes
Sent: Monday, March 24, 2008 8:27 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: exhaust gasket question 2.1
The exhaust gaskets last until the flanges either come loose or bend. Once
they start to leak, they tend to burn up. The after market exhausts
(including Dansk) have flanges that are thinner than the OEM. No, they are
not the same.
As for the head gaskets only lasting 5 or 6 years, while failure is common
to many, the trick is avoiding the cause. My Red van has only had the
gaskets replaced once in 21 years and FUN BUS still has the original set
with 254K on it. I wish the tranny lasted as long. Red van needed gaskets
and one head as road salt actually ate the head to the point that the
exhaust studs broke out of the crumbling mess. And let's stop whining
about heads and gaskets. After the exhaust is off you got two nuts for the
rockers and 8 for the heads and some prying and there off. As for
comparison to other cars, go through the phone book and look at all those
engine shops. Most of them make their living on American and Asian cars.
And most unexpected engine failures are due to support system failures
including the water boxer. Oh and the concept of engines with removable
piston liners with seals at both ends, look at most of those large tractor
trailer and industrial engines. Engines with parent bores, (cylinders cast
in the block) are considered by many to be disposable. The real heavy duty
engines have all parts that wear replaceable with the engine in place (in
frame) including the cylinder liners. Of course they are not perfect but
the Water boxer is not really that bad a design.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Scott Daniel - Shazam
Sent: Monday, March 24, 2008 10:44 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: exhaust gasket question 2.1
My experience is different on the exhaust port gaskets.
I've been using german aftermarket ones going on 30 some years.
Never a problem.
The flanges do have to be parallel to the head face where they bolt on,
and
the flanges have to be flat of course . the pipes can warp and crack..so
need to make sure the pipes are good, but good pipes, german aftermarket
exhaust part gaskets, installed carefully...they'll be fine until your
next
head gaskest job, which isn't even that far away considering how mickey
mouse the waterboxer head gasket system is. - about 5 years, maybe 6.
I can't image that a sheet of copper would work very well.
Though you were going to say to make your own copper & asbestoes sandwich
of
materials, and that could work really great I'd think.
Scott
www.turbovans.com <http://www.turbovans.com/>
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
David Kao
Sent: Monday, March 24, 2008 5:47 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: exhaust gasket question 2.1
Is it a good/bad idea to make your own exhaust gasket using sheet copper
available from hardware store? Has anyone tried this? I will soon begin
to dismantle my 84's engine and replace the tranny at the same time.
The engine will receive a set of new Cofap and a pair of used heads.
I can anticipate need of a set of new exhaust gaskets. The gaskets seem
to crap out quickly and not cheap. I am seeking an alternative.
David
--- Mike <mbucchino@CHARTER.NET> wrote:
> Metal won't get stuck to what it's clamped against, but composite may.
> Which part is easier to remove and scrape a baked-on gasket off of? I'd
put
> metal towards the head, for that reason alone............
>
> Mike B.
>
> ----- Original Message -----
> From: "Jim Felder" <jim.felder@GMAIL.COM>
> To: <vanagon@GERRY.VANAGON.COM>
> Sent: Thursday, March 20, 2008 8:18 PM
> Subject: Re: exhaust gasket question 2.1
>
>
> > Thanks, all, as usual. Metal to the head it will be.
> > Jim
> >
> > On Thu, Mar 20, 2008 at 7:01 PM, Jake de Villiers <
> > crescentbeachguitar@gmail.com> wrote:
> >
> >> I've always put the metal side to the source of the heat whatever the
> >> make
> >> of engine but I remember a post not too long ago that espoused the
> >> opposite.
> >>
> >> In 35 years of hot rodding etc I've never had a problem when putting
the
> >> metal side to the exhaust port. :)
> >>
> >> On Thu, Mar 20, 2008 at 4:44 PM, Jim Felder <jim.felder@gmail.com>
wrote:
> >>
> >> > My first question is why does a Vanagon full gasket set come with
only
> >> > two
> >> > head-to-pipe gaskets when it requires four?
> >> > My real question is which side goes toward the head, the composite
side
> >> > or
> >> > the metal side?
> >> >
> >> > Obviously I'm talking about the kind that's thin steel bonded or
> >> > crimped
> >> > to
> >> > a composite material.
> >> >
> >> > Thanks,
> >> >
> >> > Jim
> >> >
> >>
> >>
> >>
> >> --
> >> Jake
> >> 1984 Vanagon GL
> >> 1986 Westy Weekender "Dixie"
> >> Crescent Beach, BC
> >> www.crescentbeachguitar.com
> >> http://subyjake.googlepages.com/mydixiedarlin%27
>
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