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From: A Jensen (no email)
Date: Mon Aug 02 2004 - 13:37:05 EDT
Lary wrote:
I think Arild's observations support my Luddite position that electronically
controlled and electronically dependent engines have no place aboard a
single
engined long range trawler.
>>>> snip<<<<<
Once started, my old Perkins will continue to run even if I throw all the
batteries overboard. All electronically dependent engines should have a fall
back
mode which will permit the engines to operate with reduced, but adequate,
power even with total electrical systems failure.
REPLY
Larry, somehow I failed to make my point clear.
The real problem is that the people involved in using the new technoilogy
simply do not understand the implications of the technology they are working
with.
Digital diesels do have a back up mode of some kind. I have personally seen
a Detroit engine run without the controller being connected to power.
The point I failed to make is that we do not have adequate means of
monitoring and managing the systems we are busy becoming reliant on. The EPA
cohorts are busy mandating all sorts of things for the sake of cleaning up
our environment.
Unfortunately this often creates additional problems unforseen at the time
the law is invoked.
I have personally been caught out by this tendency of GM computers to shut
down the engine without warning when teh batery voltage drops below a
certain threshold. With all the electronics already on board couldn't they
also include an early warning?
Secondly, each manufactuer seems bent on developing proprietary schemes for
theior products.
I don't know if this is an attempt at excluding everyone except "factory
authorized repair shops" or if this is simply misdirected intellectual pride
on the part of the engineers designing the systems.
I do know that much of the design changesa re driven by the EPA mandate to
reduce fuel consumption, reduce total emissions of obnoxious combustion
by-products and so on.
Much criticism has been directed against the gas guzzling SUVs. My own
observations has ben that many of them are driven by women who are terrified
at the prospect of driving a tiny light weight fuel eficient car on the
highway because they feel unprotected compared to siting in abigger SUV.
The engine industry as a whole is striving to produce lighter weight
engines. One of the consequences of this is the greater use of plastic pats
and reduction of iron copper and steel wherever possible.
This has resulted in smaller alternators and starter motors. Greater use of
engineering plastics in every part of the engine means they are no longer as
strong and long lasting as before.
Haven't you bought a new replacement pat only to discover that the new part
uses plastic instead of brass or steel?
My concern is with the changes to OEM electrical equipment. Given that
almost all marine engines are derived from automotive and industrial engine
blocks; what does this trend hold in store for boat applications.
When alternators are no longer suitable as main chagers but only as "battery
maintainers" what do we use to recharge big house banks?
The obvious answer is to add a second alternator. Check out the cost of
adding a complete PTO and mounting bracket system on a typical Lehman
engine. In the case of the PT installations the builder has used a dropped
engine mount that prety wel eliminates any possibility of side mounting the
big alternator.
I priced out such a job and the mechanical work amounted to as much as the
cost of the Balmar alternator.
I see more and more plastics used in all sort of elctric equipment. The
ostensible reason is to save weight.
Unfortunately when such a plastic part gets stressed it breaks and trying to
glue such plastics together is almost hopeless.
I have seen brass, aluminum, and even cast iron soldered, arc welded or
brazed to repair it and the repair has lasted for years.
My Vortec engine has plastic fuel lines in the high pressuer section. When
it backfired the plastic melted and I burned out the whole system. Cost
$1500 to repair. My diesel has a plastic timing belt! And the fuel filter
system is roughly half plastic by parts count. I had one diesel with an
aluminum head to save weight. Oh sure the cylinder liner was steel, but
nearly everything else was aluminum or plastic. When the transmission began
slipping the cause was a worn plastic part.
the repair shop used brass part fore the repair and guranteed it for life.
I teach an electrica course to get the guys ABYC certified. Someof these
people have 10 years expeience in the marine industry. What is distubring
is how little these people actually know about the technology they are being
asked to install.
Manufacturers are less and less forthcoming with technical details
concerning how their products work or the underlying principle behind the
design. These marine electricians are simply working by rote, with little
comprehension of the broader picture.
regards
Arild
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