Date: Sun, 23 Sep 2012 11:34:56 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: How To Choose YOUR Engine Conversion-Engine Management
Content-Type: text/plain; charset="US-ASCII"
I wasn't thinking so much of normal engine operation/control but rather the
response to failure situations. If a support system such as the cooling
system fails, fan not turning on, thermostat not opening, loos of coolant
what is the response? For the loss of coolant there is going to be an engine
trauma not matter what but in the Vanagon you can run until a meltdown.
Modern engines may shut down go into reduced power or some will do
alternating cylinder shutdowns to keep the engine running without the
meltdown.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Jim Akiba
Sent: Thursday, September 20, 2012 11:54 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: How To Choose YOUR Engine Conversion
On Thu, Sep 20, 2012 at 8:43 PM, Dennis Haynes <d23haynes57@hotmail.com>
wrote:
> If you really think this through the real problem with the Water boxer
> or Vanagon reliability is the support systems.
I enjoy thinking about this problem. If the primary goal is to keep the van
running with the lowest risk of a showstopper, and if by "real problem" you
mean the most important or fundamental problem in doing so, then I partly
agree with you. I think engine management is overlooked and is often the
source of problems. In fact this is exactly why Bostig came to vanagonland.
Brady bought a big valve Boston Bob engine in 2003 or 2004 for about $4k.
It lasted 18k miles. It did so not because the rebuild was no good, but
because of engine management failure that caused overfueling. It was
running rich enough to blow black smoke and get abysmal mpgs for 500 miles
or so, which gas washed the cylinders, diluted the oil with gas and put the
equivalent of 300k miles on the internals. It was a failure of engine
management combined with operator information failure, that allowed the
condition to last for long enough to result in the damage.
If you want you can pick out another level of granularity into "engine
management" and drill down to ID the combination hardware failure (O2
sensor) and the strategy/software failure (closed loop fuel trims are
allowed in excess of +/- 50%, limiting it to 10-15% would have prevented the
gross overfueling). You can also move along the hardware failure timeline
and say the O2 sensor wasn't replaced according to maintenance schedule, so
therefore the most important problem is operator information in the form of
maintenance and care... but I think the point is that it's usually a
combination of things, and they all need some consideration. I agree that
engine management is overlooked in vanagonland. But it isn't any "more"
important than any other link in the chain (although it certainly can be).
If any link breaks the chain breaks. I would however agree that it is the
most important problem if your goal is to run a waterboxer.
>The Zetec is nice that there are
> some protection features built into the computer and it is a modern
>engine and control package but if the 20+ year old support systems are
>still there she may still have to walk home.
That's exactly right, if you lose your ignition switch or your battery is
dead, it doesn't matter what you have in there. The point is to use
resources on each link in the chain up to the point of diminishing returns
for that link. That point varies individually for each link for each van.
It will also be affected by the operator's information, some being more
impacted than others. To make it more complicated, the point also moves over
time for some links. Modelling all the links to determine where the
diminishing returns begin for each and iterate through improving solutions
up to that point that you hit it for that link is a way of trying to get it
right. Modelling the links can be replaced by trial and error as well, but
people don't like that method if they are the ones getting the errors.
>From years of experience especially with today's lubricants engines
>are healthy or not. A very high mileage engine if healthy is a
>well-tested engine and should continue to be used until there are
>indications that it needs work.
I agree with the spirit of the statement, no sense in replacing something
perfectly good with utility yet to give. But whether I agree with the
statement completely depends on a couple things. I fully agree with it if we
are talking about a van that belongs to you, me, Brady, Don, Neil, etc... I
would not agree if the van belonged to my mother (sorry ma).
She simply wouldn't have the information needed to judge when something is
going to need to be addressed lest it become a much larger issue. So
problems could manifest themselves in majestic cascades of failure (some are
truly sculpturework examples of Murphy and his law) or sudden catastrophic
style failures. Not to mention being costly, esp if long distance towing is
involved.
Indeed sometimes "indications" of needing work are simply not enough
either. More common than anyone would hope is the old tactic of sudden power
losses being countered with mashing the gas pedal to compensate.
Likewise, what should be the response to complete lack of an oil reading on
a dipstick with a massive puddle of oil on the ground beneath it? Why
naturally it's to go get some oil at the local parts store... in the van
that has no oil reading. The lack of oil reading on the dipstick was the
indication the engine needed something, and destruction of the engine was
the result. Sometimes indication is not enough to prevent failure even for
an engine that should have a long life ahead of it.
>No knocks, smoke, good compression and
> oil pressure, keep on driving. For the water boxer, pop a head gasket,
>pretend you are paying someone to do a water pump and timing belt with
>tensioners on many modern cars. The cost is a about the same.
For some engines that's true, for others it's the opposite condition, you
don't need to pay anyone to do any of it but if you choose to it's still
less $$. If changing a water pump is little more difficult or time consuming
than doing an oil change, whether you do it yourself or a mechanic does it
it's going to be faster and easier or faster and cheaper. If the engines and
parts are everywhere they will be cheaper too. Besides even if the cost
aspect was the same, they still aren't really equivalent. Head gaskets are
more likely to reoccur at less than the original interval or stress level of
failure as a result of it having required replacement/being replaced,
whereas a timing belt or water pump replacement isn't.
>Now imagine if
> you kept the engine and it ran to 250K. What could you have done with
>the money used for the Zetec? Now if the engine is gone and you have
>to replace it anyway now you just need to consider the up-charge.
There are plenty of people that have done just that, and saved themselves
huge amounts of money and spent it on travelling. There are also plenty of
people that have diligently maintained their original setups, and ended up
throwing good money after bad. Only after they have already either spent the
equivalent of the cost of a conversion, or more usually about half (if they
lose a rebuild fast), they then spend the money on the conversion. This is
just over 40% of our customers anyhow. The question is which one will a
given person be?
Unfortunately the person in question is usually not in a great position to
make a truly accurate guess as to where they might end up and how they'll
have fared in terms of total time, effort, and money invested. Also
remember that if the engine goes "on it's own time"
the costs can be huge both in money, time, and timing... I think the timing
for replacing or maintaining an engine is best done on the operator's
preference, not the engine's as it the lower risk of timing related cost
overuns.
Jim Akiba
