Date: Sat, 26 Jan 2002 20:52:14 -0600
Reply-To: Stan Wilder <wilden1@JUNO.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Stan Wilder <wilden1@JUNO.COM>
Subject: Re: Aircooled lifter noise
Content-Type: text/plain; charset=us-ascii
It is never my intention to publish false or misleading information.
I try to be careful about this because many new comers seem to retain the
first thing they read about their problem and accept this as fact
discarding better more accurate information that may follow or completely
missing the newer better information because they muddled through their
problem to a solution.
This link started out as Aircooled lifter noise and proliferated into
second year engineering scenarios about what causes heads to fail.
As I necromance through the half dozen type IV cylinder heads I have
under my work bench I can clearly recall the symptoms of the engines that
they came from. Getting into these war stories is useless except to
enforce an *I told You So Story*.
In every case that I get involved in discussions about lifter settings I
provide a link to Boston Bobs excellent tutorial on valve settings. I
sincerely believe that second opinions are important.
Historically I have purchased Vanagons with two bad heads (no matter I
crush Vanagons out). In the engine disassembly process I can see the
trail that led to the cylinder head failures. Flame cutting on the
cylinder to head contact area, flame cutting around dropped seats, flame
cutting around the piston crown, broken lands on pistons, scored
cylinders, chipped valve stems, hammered rocker arm adjusting screws,
cracked heads, stripped spark plug threads, wrong spark plugs, heads
without head bolt washers, detonation pits in piston tops and cylinder
head chambers, injectors with chips out, dried out injector seals,
leaking vacuum lines. Many of the engine have multiple contributing
problems. (Tip: Torque wrenches are for loosening too. Keep notes as you
disassemble your engines.If you find bolts or nuts that has been over
torqued replace them with new parts.)
Many of the problems surrounding engine failure are caused by lean
running to meet state inspection requirements. I was fortunate enough to
meet a VW guru that also had a state inspection station and he advised me
that my Type IV engine would self destruct if I tuned it lean to pass the
inspection and maintained it that way. He explained that the fuel air
mixture should produce a spark plug burn the color of coffee with cream.
His further evaluation was that the injectors must be in excellent
condition and all deliver the same amount of fuel with each injection,
stating that a single too lean injector would cause overheating of all
cylinders since the lean hot burn made all the other cylinders work
harder, effectively a 3.5 cylinder engine trying to do all of that work.
I've followed his advice and haven't had a cylinder head failure or over
heated engine in seven years (except the one road rage event that I
chronicled the other day, and I didn't damage a head I busted ring
lands).
Just throwing a rebuilt engine into a Vanagon is very short of having a
properly functioning engine system.
Most people consider a Porsche, Ferrari, Lamborgini as super tuned
vehicles and I must agree but the little humble VW AirCooled power plant
is also super tuned. a 1/8" off on your chezy little degree arc after you
tighten down the bug screen over your fan will cause you to set the
timing wrong. With the VW aircooled everything must be in the *notch*.
You don't have variables that produce more consistent power than the
settings outlined in the Bentley, Hayes, Tom Anderson manuals. (exception
being those stinking hydraulic lifters that are nothing more than solid
lifters with a tiny cushioning because the oil column is softer than a
steel column.)
I seriously doubt that I anyone on the list could tolerate the multiple
problems that cause cylinder head failures. They'd simply address the
problem before it got that advanced.
With newcomers to the list they have purchased problem vehicles that have
been through abuses that the previous owners placed on the vehicle out of
ignorance or indifference. Twenty years is a long time guys. Its only VW
Van owners that are running 20 year old cars on a daily basis (Cubans
exempt from this).
I had go through a lengthy learning curve myself on the VW aircooled
engines and the more I learn the more respect I have for this tiny 180
pound power plant.
Thats it folks!
I'm officially out of the lifter discussion.
Stan Wilder
83 Air Cooled Westfalia 278K
On Sat, 26 Jan 2002 17:54:40 -0500 "G. Matthew Bulley"
<gmbulley@BULLEY-HEWLETT.COM> writes:
> Perhaps you have confused my assertion.
>
> Jake has asserted that un-adjusted valves are a cause of valve seat
> failure because the valve "slams against the seat".
>
> I am saying that (while valve seats are a common cause of problems)
> slack valves that clatter are NOT slamming on the seats, the rocker
> arms
> are (fairly harmlessly) clattering against the valve tips.
>
________________________________________________________________
GET INTERNET ACCESS FROM JUNO!
Juno offers FREE or PREMIUM Internet access for less!
Join Juno today! For your FREE software, visit:
http://dl.www.juno.com/get/web/.
