Date: Fri, 7 Apr 2023 22:45:01 -0500
Reply-To: John Rodgers <jrodgers113@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Rodgers <jrodgers113@GMAIL.COM>
Subject: Re: When & why replace heads? A Friday Dennis Discussion.
In-Reply-To: <BL0PR05MB491623FFF98ED52416C98B80A0969@BL0PR05MB4916.namprd05.prod.outlook.com>
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Dennis and all.
The many reasons, Dennis, you listed is why I FINALLY opted for the Subaru
engine. I put a completely rebuilt 2005 2.5 L engine in my '91 CARAT. I got
desparately tired of the troubles the 2.1 L wasserboxer was causing and the
continuing cost of repairs. I am so very glad I did. For the most part
trouble free operation, plenty of power, and better gas mileage. BUT I am
keenly aware of the fact these engines can give trouble also. They are not
perfect, but I find them better than the old WBX. The big plus is that this
is a modern design, modern metallurgy, modern electronics, and parts are
plentiful. I am enjoying the heck out of mine.
On Fri, Apr 7, 2023 at 6:33 PM Dennis Haynes <d23haynes57@hotmail.com>
wrote:
> For many engines the cylinder heads and the sealing of the heads to the
> block tend to be the first thing to require service. The Vanagon adds an
> additional "dimension" to the opportunity for failure due to the method of
> sealing at the top of cylinders and then the outer gasket sealing the water
> jacket.
>
> As for removing the heads for repair or replacing them that is part of a
> diagnostic and inspection process. The only reason that the heads would
> really need to be replaced is if they are damaged or cracked. Fortunately
> Waterboxer heads are available and relatively cheap. For most engines heads
> get repaired including welding and machine work and there used to be
> machine shops in many parts stores that provided those services. At current
> labor rates even a simple valve seat grind and valve replacement will
> quickly exceed the cost of anew head, especially if the guides also need to
> be done.
>
> So lets look at the most common problems with the Waterboxer heads.
> Probably the most common is leaking at the outer water jacket gasket. Next
> is failure of the seal between the heads and the top of the cylinder(s).
>
> For the outer water jacket gasket leaking or failing, this is always due
> to the gasket and/or the sealant failing. The failure could be just a
> failure of the sealant causing a minor drip or the gasket actually spitting
> and allowing for a near instant dump of coolant. Failures can also happen
> quickly after a replacement due to inconstant dimensions of the gasket, the
> case, head, and yes the cylinder barrels or the base of the bores that the
> cylinder barrels sit on. I have had this gasket fail and embarrass me on a
> number of occasions.
>
> For the sudden failure splitting over time, this is usually the result of
> the gasket seal having a slow leak. Which will then cause the head to
> corrode under the gasket. This corrosion will grow and eventually penetrate
> the gasket forcing it to split on the flat surface. Sudden coolant loss.
> This event is a trauma to the engine and can cause a lot of damage quickly.
> Warped and cracked heads along with tweaking the head studs. If the outer
> gasket is the only concern, if the head can be pulled without disturbing
> the cylinders it is common to pull the head(s), clean the surfaces, also
> clean the groove sand replace the o-rings on top of the cylinders, new
> gaskets, with proper installation and torquing the heads may be all the is
> needed to set things right.
>
> For the top of cylinder to head seals the usual symptom is in-ability to
> keep the cooling system free of air and coolant being pushed out when
> engine is heated and underload. Sometimes this is illusive only happening
> after some extended driving period. This failure is almost always due to
> the studs losing tension which can happen for a number of reasons. Also, if
> the cylinders are not perectly square and level as a set, you won’t get a
> good seal up there. This can be caused by miss matched or out of spec
> cylinders or a worn, damaged, warped engine case. If the cylinders are
> parallel but just a different height different thickness gaskets may be
> used at the top of the barrels to compensate. You will need to make or have
> made custom gaskets from copper sheet.
>
> One needs to consider that as part of removing the heads things can
> quickly go wrong or be found that will move the job to engine replacement.
> You need to be prepared for this possibility for both the time and money.
> Keep in mind that for as much this engine can accept some repairs like may
> automotive engines it is designed as a throw away. Going back to even the
> beetle days these alloy based engines supplied as dealer supplied factory
> rebuilds almost always had a brand new case. Rebuilt heads and most
> internals, but always a new case. Many problems will come back to a bad
> case.
>
> Dennis
>
>
>
> -----Original Message-----
> From: Vanagon Mailing List <vanagon@gerry.vanagon.com> On Behalf Of Dan N
> Sent: Friday, April 7, 2023 6:11 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: When & why replace heads?
>
> *"My question is what are the main reasons for replacing heads and how do
> you know when you've reached that point?"*
>
> Compression test and leak down test? - The rings and cylinder walls may
> still be good but the valves and valve seats are worn...
>
> On Fri, Apr 7, 2023 at 3:01 PM David McNeely <davmcneely40@gmail.com>
> wrote:
>
> > Very ignorant here, but my feeling is leaking heads mean it's time to
> > do the job. Do you want the engine to blow up when moving at high
> > speed (or any time for that matter)?
> >
> > On Fri, Apr 7, 2023 at 6:45 AM Spencer Allen <soxndubs1951@gmail.com>
> > wrote:
> >
> > > I had my 85 stock westy inspected and some brake work done and the
> > mechanic
> > > says I should replace the leaking heads. I may have jumped the gun
> > > and ordered the GW super duper ($$$) reworked AMC heads. The thing
> > > is my OE heads have been leaking for the last 20 years and 60K I've
> > > owned it. The major leaking occurs during the winters while it's
> > > stored in my garage so when spring comes I have to top up the fill
> > > tank with about a qt of coolant. Summer it does drip but nothing
> > > major. Engine runs fine with no white exhaust smoke. My question is
> > > what are the main reasons for
> > replacing
> > > heads and how do you know when you've reached that point?
> > > Spencer
> > >
> >
>
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