the fink
Letters
to the Editor
I love our readers. Many of them have told me that they read aBr from cover to cover, month in and month out. And many
don’t just read the articles. They also comment on them, with some taking us to task for incorrect information, some adding
constructively to an article, and some disseminating our articles to a wider audience. Here are just three recent examples:
#1 Dear Mr Erasmus
Comment on “Auto Alert” by Frank Beeton of Automotive Business
Review. June 2014
I read with great interest Mr Beeton’s discourse titled “Technological
Lemmings” and I support his conclusion that the manufacturers are
caught in an ever intensifying technology race to keep up with the
competition. I have often argued that that the more gadgets you have
on a vehicle the more there is to go wrong. Having said that I do not
believe that this is all bad news and could even offer opportunities
for innovative solutions to problems that come with technological
advances. UDF (Pty) Ltd (for whom I work) situated in Edenvale,
Gauteng is just such a company having discovered and utilised an
opportunity brought about by advances in engine design. Beeton
states that stringent environmental legislation, the demand for better
fuel economy and peer pressure have fuelled this technology avalanche
whereas the different standards applying to differing geological
locations cause problems for operators outside of the more stringently
legislated regions.
The fact of the matter is that whilst engineers and designers have
introduced wonderful new systems to meet and exceed these
requirements the recommendations for fuel cleanliness that makes
these systems work properly has lagged behind for many years.
There also seems to be a disagreement between the vehicle/engine
manufacturers and the makers of the injector system components
that are used. The signatories of the World Wide Fuel Charter 2013
recommend that the fuel supplied into the vehicle’s tank should be a
minimum of 18/16/13 as measured according to ISO 4406 cleanliness
code. The fuel system component manufacturers however recommend
that the fuel supplied to the pump and injectors should be a minimum
of 12/9/6 also according to ISO 4406 cleanliness code. This equates
to 64 times cleaner than the vehicle manufacturers recommend. The
vehicle manufacturers supply an on-board fuel filter system to “achieve
a fuel cleanliness that will enable the fuel injection components to
function reliably and within their designed operating parameters
throughout the life of the component” (quote from Mr Brad Cook of
Lubricare (Pty) Ltd).This is a noble ideal and one to be lauded by all
but we have to ask the question which most suppliers are reluctant to
commit to. What is the “life of the component”?
It is a common belief that the engine fuel filter installed by the OEM
will provide the required level of contamination protection in order to
achieve reliable operation. This is a fair and reasonable assumption to
| words in action
make. However, there are several key aspects regarding the application
of engine fuel filters which will call into serious doubt the ability of many
to achieve the desired cleanliness level now being sought (also from
Mr Brad Cook). These factors include vibration, pulsating flow, engine
speed, filtration efficiency and dirt holding capacity all of which are not
considered necessary to test when evaluating a filter’s performance.
Regarding filter holding capacity, the vehicle manufacturers do not take
into account that most of the dirt (as much as 80%) getting into a fuel
system comes in with the air breathed into the tank as the fuel is used.
All of these factors have a huge negative effect and make it virtually
impossible for the filter to clean the fuel to meet ISO 4406 code of
12/9/6 required by the fuel system component manufacturers.
At this stage we should also like to make readers aware that the ISO
4406 cleanliness code as recommended by W.W.F.C. signatories
refers to particle sizes of 4, 6, and 14 microns (millionth of a metre).
The dynamic clearances between the components of an injector are
in the range of 1 to 4 microns so we question whether these minimum
standards (maximum numbers) and particle size classifications are good
enough. Our field experience and feedback from many users of diesel
powered equipment in Africa suggest that they are not. The dirt particles
floating in diesel fuel vary considerably in size and typically the numbers
double with each micron decrease in size. So whilst there may be
1 000 particles of 10 microns the number of 1 micron particles could
be as high as 1 000 000. The total volume of the dirt particles is roughly
equal for the different sizes so whilst a filter may be able to remove the
majority of the larger particles the multitude of smaller particles of equal
total volume is allowed through to damage the fuel system component
parts like an army of ants working in unison to overcome and devour a
much larger creature. Ultra-fine Depth Filtration systems are designed
to overcome all of the problems discussed above returning to the
user huge saving in fuel consumption, component repla 6V