Date: Sun, 9 Apr 2023 16:02:51 -0700
Reply-To: Dan N <dn92610@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dan N <dn92610@GMAIL.COM>
Subject: Re: When & why replace heads? A Friday Dennis Discussion.
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Happy Easter everyone... :-)
A story about the WBX engine... Some years ago I bought a running WBX
engine (the owner went to Subie), mileage unknown (broken speedometer),
some head gasket leaks. I brought it to my mechanic (his specialties are
aircooled bus and vanagon).
He took the engine apart and called me up to discuss. He showed me the
piston walls, they still have honing marks on them... He said the engine
has about 60K/70K but needs new or rebuilt heads, they have cracks in the
space between the valve seats. So we decided to put in new heads and after
about 60K it is still running well.
On Sun, Apr 9, 2023 at 7:03 AM Dennis Haynes <d23haynes57@hotmail.com>
wrote:
> Happy Easter and the coming of Spring.
> From experience the Subie 2.5is amongst my favorite. While I have seen
> some issues with the few I have worked on the major downside is the effect
> on the transmissions, especially the automatics. Here is NY we also have to
> consider the issue of getting caught. While we don’t have regular
> enforcement (95 and older do not get scheduled emissions inspections) we
> other wise follow the CARB. As an added twist to prevent someone placing a
> non OBDII engine into an OBDII engines 93 and later are also regulated.
> AFAIK no one has yet had a Subie 2.5 certified or an approved exemption for
> the Vanagon. With the number of suppliers offering this setup maybe some
> day the investment will be made.
>
> For the Waterboxer, there are still many of them running with original
> engines in place, even with some repairs. The engine in Fun Bus has
> outlasted 3 transmissions and at this point the chassis. The mount for the
> right rear trailing arm is failing so the van is off the road waiting for
> some major welding repair. For my 91 the heads were replaced at 168K. At
> 248K the exhaust valve for cylinder #2 burned. I pulled the heads,
> replaced the one valve, removed the liners and replaced the rings. Now at
> 297K and running strong. Usage has dropped since I acquired a Denali Crew
> last May. But even with the flywheel leak this engine doesn't burn oil and
> has made numerous NY to Florida trips. The final drive for the transmission
> is in need of replacement as the pinion bearings are loose so I know the
> housing is shot. That trans is also original except for the parking paul
> getting busted and the torque converter. Yes they do fail.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List <vanagon@gerry.vanagon.com> On Behalf Of John
> Rodgers
> Sent: Friday, April 7, 2023 11:45 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: When & why replace heads? A Friday Dennis Discussion.
>
> 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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