This is a report about a
work in progress that started out to be testing and reporting on bypass oil
filters and wound up being a lot more ‑‑ but that is often the case
with works in progress
All of my observations
about bypass oil filters have been on products manufactured by Gulf Coast
Filters (GCF). It should be noted that
I have no financial interest or connection with Gulf Coast Filters in any way
and have no interest in whether you purchase anything because of these
reports. The information is from my
observations on my equipment. Its
purpose was for my own benefit. I just
share the information I have gathered for any use ‑‑ or none ‑‑
you wish to make of it. I have learned
that there are many different manufacturers of bypass oil filters. Among the names that jump
out are Enviro, Filmax,
Premo Plus, TF Purifiner, and the one that I have observations from, Gulf Coast
Filters. I have made one phone call to
one other filter manufacturer, Fleetguard, and they also make a bypass oil
filter.
At the outset, I am happy
to report to you that all of my experiences in this field indicate that the
competition is civil. They all think
theirs is the best, but they don't shout that the competitor's doesn't work. They all agree on the basic premise of operation
and make their case on the special merits of their own product. Isn't that a delight?
It is of historical
interest that bypass oil filters were around before full flow oil filters. I had a client whose father made him equip a
fleet of trucks with bypass oil filters in the '30s when no other oil filters
were on the engines. It seems that the
bypass filter concept died when it was thought that the, then, new full flow
oil filters did the entire job. It had
a rebirth when extended oil drain periods became desirable in industry.
For those who were not
around when this thread was active a few months ago, a little introduction is
presented below. In addition the prior
post about the Portable Oil Analyzer will give some more additional background
on this subject. Old hands who have
heard more about this subject than they need can just hit the delete button.
The Bypass Filter Concept
The bypass oil filter
operation is to circulate ALL the oil through the full flow oil filter and
circulate approximately 10% of the oil through the bypass oil filter and return
it to the crankcase. Generally the oil
goes to the full flow filter first and then the bypassed part goes through the
bypass oil filter before returning to the crankcase. The concept is that the full flow filter must always pass all the
oil to keep from starving the engine.
Time has shown that to do that, the full flow filter can only take out
the large size debris. There remains a
lot of small stuff that is very harmful to the moving parts of the engine. The bypass oil filter can be designed to be
much more efficient than the full flow oil filter because no
catastrophic harm results
if the bypass filter gets stopped up.
It just stops producing its extra benefits.
Two broad classes of oil
filters are "Surface" and "Depth." A full flow oil filter is almost always a
"Surface" filter, and a bypass oil filter is almost always a
"Depth" filter. In surface
filters, the oil goes through the filter more‑or‑less
perpendicularly to the filter medium. The
filter gets to work on the oil in one pass at the surface of the filter. In depth
filters, the oil must pass
through a filter medium of considerable depth B it must stay in contact with
the filter medium a relatively long time.
It should not be surprising that
the full flow, surface, oil filters filter in a general range of 10 to 30
microns, and the bypass, depth, oil filters filter in a general range of 1 to 5
microns.
There is an additional
class of bypass, depth, oil filters that I'm aware of ‑‑ "Absorption." That is to say, that the filter medium in
these filters is made of material that will absorb moisture. That material is often paper and in the case
of GCF, either paper towels or toilet paper.
When Does The Oil Need To
Be Changed
The whole bypass oil thing
came about because of the desire of industry to extend the oil drain interval
in commercial operations. Changing oil
in commercial operations is a direct deduction from the bottom line of the profit
and loss statement so there has been a lot of interest in safely extending the
drain interval to improve profits. If
that situation did not exist, you'd not be reading this now. Our industry is just not large enough to
support the research and manufacturing necessary to keep this issue alive.
When do you need to change
oil? The short answer is when it gets
dirty. That can be extended to a more informative answer. The oil should be changed when the
contaminants are higher than desirable, and/or the additive package is depleted
more that desirable, and/or the viscosity of the oil is unsuitable.
Most of us non‑commercial
diesel engine users change oil at the hour interval recommended by the engine
manufacturer or at least once each season.
That may produce the desired results, but there is a better way. The
better way is to change the oil when laboratory oil analysis shows it is time
to change the oil. That may mean
changing the oil after 50 hours, 100 hours, 400 hours, or never. For starters, changing oil this way may save
you some money ‑‑ the laboratory I use charges $12.00, and the
direct oil and filter cost to change my oil is just a little under $40.00.
The Value Of Oil Analysis
Saving a little money
and/or labor by using oil analysis may be a small incentive to use laboratory
oil analysis to determine when to change oil. But the real benefit of doing it
that way is that the oil analysis will give you a history of the health of your
engine. Concentrate on
"health." The oil is the
lifeblood of the engine and most of the terrible things that are going to
happen to your engine will be forecast by the condition of your engine oil.
The first oil analysis may
tell of many immediumte problems, but the real value is a continuous record
that gives the trends over time. It is
great that we don't need to interpret the laboratory results ourselves. The laboratory will do that for us just like
our doctor interprets the analysis of a blood sample.
There has been a heated
thread, on the list, about the difference in dependability of single vs. dual
engines. Laboratory oil analysis
history, and corrective actions as indicated, are quite likely the most
important things you can do to increase the mechanical dependability of your
engine(s) ‑‑ single or dual.
The Problem With Laboratory
Oil Analysis
Say What? CaptnWil has just tried to sell laboratory
oil analysis, and now he is saying there is a problem with that very thing.
The problem is that the
information we get from laboratory oil analysis is only valid for the instant
in time when the samples are taken. It
gives us enormous amounts of information at the moment of taking the sample,
but we are in the dark until the next oil sample is taken and the laboratory
analysis is done. For those who use a
boat less than 200 hours per year, it is likely that only one laboratory oil
analysis would be made in a year. That is certainly more information than is
normally known, but it is still a long time between getting valuable
information.
The solution is to
supplement the laboratory oil analysis program with a Portable Oil Analysis
reading after each day's operation as indicated in a previous post.
The information we need is
gained in a digital nature. Just like
increasing the clock speed in our computers gets us information faster, using a
Portable Oil Analyzer each day will keep us informed about the health of our
engines on a daily basis.
Where Are The Bypass Oil
Filters
Take special note that
bypass oil filters have not been mentioned at all in the last four
sections. It is not necessary to
install a bypass oil filter to have most of the knowledge that can come from a
formal program of both Portable and Laboratory Oil Analysis.
It has been argued that
boats that are used as little as most pleasure trawlers can't justify the
expense and trouble to install a bypass oil filter system. Another argument has been that since the
normal life of a trawler diesel is longer than the owner will keep the boat,
bypass oil filters should not be considered.
The conclusion of both arguments is to just change the oil often and all
will go well. Until my preparation for
Trawler Fest in Melbourne Beach, I would have agreed with that argument
entirely ‑‑ if the oil analyses procedures described above are
followed.
In the next post, I'll
report some observations that were not only surprising, but shocking as
well. Those observations will give you
some more information to make a judgment about this whole matter.
CaptnWil
SUMMARY FOR NEWCOMERS
There is a large body of
unbiased technical reports and laboratory oil analyses to verify that Gulf
Coast Filters (GCF) bypass oil filters keep engine oil in serviceable (almost
new) condition for an unlimited time in commercial and industrial equipment
that runs long and hard under adverse conditions. The sources agree that keeping the oil in new condition reduces
the wear in the engine materially and increases the life of the equipment.
Among those sources of information are Shell Oil Company and The North Carolina
Ferry System. More details are in the
first reports that should be in the archives.
Recently, I have personally
seen and listened to a Detroit diesel engine equipped with a GCF bypass oil
filter that is about to, or has just, passed 1,000,000 miles with one oil
change. The oil change was done by mistake.
All of this came from
equipment that used GCF filters. While
the information I have and my experience is with this brand equipment only, I
would not be surprised if similar results can be obtained from other depth,
absorption‑type bypass oil filters.
I want to emphasize that the purpose of this report is the concepts
presented and not in a brand of equipment.
All of those results were
from equipment that runs hard and long.
Often it runs at near full load.
The information was from commercial and industrial equipment and that
means that the equipment operation is vastly different from the way we operate
our recreational trawlers. I could not
doubt the truth of the facts, but I wondered how all this related to our type
operation. The tests I conducted were
intended to answer that question.
INITIAL RESULTS
A paper towel bypass oil
filter was installed on my trawler's main engine, and a toilet paper bypass oil
filter was installed on the generator.
Oil analyses were made before installation of the filters and at more
frequent intervals than normal to check results of the Portable Oil Analyzer
(POA). My tests were almost non‑events.
The filters improved the condition of the oil and it remained almost
like new. For example, after 302 hours
on the filter and 468 hours on the oil in the ADC Ford main engine, the
laboratory oil analysis was so good that the lab manager asked if I had made a
mistake about the engine hours. The POA
reading was 1.4. Remember that the POA
says change the oil at a reading of 4.6.
302 hours ago the POA reading was 1.2. The results on the generator are
even more spectacular. I have
absolutely no doubt that these things work.
START AND STOP
One of the things that
concerned me was how our "Start‑and‑Stop" driving impacts
the operation. Most of our boats sit at
the dock much more than they travel.
Often our boats sit at the dock for a whole winter. Most of us have a concern about what happens
to the inside of our engines during long lay ups.
The POA was a great help
since I could get a result after each day's operation. In my engine the readings increased the
first day after a long lay up. Then
they decreased and leveled out.
We started our winter
cruise after a 3‑month lay up and put 198 hours on the engine. The POA readings went from 0.95 to 1.2 to
1.8 and then during the cruise decreased to 1.4. During this cruise we ran almost every day. You should understand that anything under
2.0 is almost new oil. All of these
readings are excellent, but the most interesting thing is how being underway is
better that being at the dock ‑‑ in more ways than one! Of special note is the fact that the 3‑month
lay up didn't do any harm to the oil that was not corrected by the bypass oil
filter. The POA didn't indicate
changing the oil when putting the engine back in service. In all of this, laboratory oil analysis
supported the results of the POA.
BASIC CONCLUSIONS
1. POA analyses and
laboratory oil analyses are important tools that can provide valuable
information in the operation of any engine. 2. Installing a bypass oil filter
can greatly extend your oil change interval, and will reduce the wear in your
engine materially.
CONCLUSIONS BEFORE TRAWLER
FEST
The benefits of using POA
and laboratory oil analyses are valuable in all situations. The real question to answer is does the
benefit justify the expense and trouble of installing a bypass oil filter
considering the way you operate your boat?
Initially I felt one should
consider installing the bypass filter if he used his boat more than 200 hours a
year and wanted long life.
SOMETHING HAPPENED ON THE
WAY TO TRAWLER FEST
Remember that this is still
a work in progress and I discover new (to me) information all the time.
One of the features of the
GCF filter is that the used medium can be inspected when it is replaced. Even though all the readings indicated that
the filters did not need to be changed, I wanted to display them at Trawler
Fest in the presentation. I planned to
arrive at Trawler Fest by boat and change the filters the day before the
presentation. Circumstances developed
that made it necessary to return home on the boat and travel to Trawler Fest by
auto. I had a lot of equipment to
display so I decided to take the pickup with a Cummins 6BT engine in it.
Before leaving home, I
changed the bypass oil filters in both the main engine and generator. I was shocked. Right there on the top of both used filter elements was some
debris ‑‑ debris big enough to see. The stuff on the main engine bypass filter was as big as large
fleas on a dog. The stuff on the
generator filter was white and smaller.
Both of these engines are
almost new. The oil and full flow oil
filters have been changed exactly as recommended by the manufacturer up to the
time of installing the bypass oil filters.
The generator came with a special "break‑in" oil filter
that was twice the size of its normal full flow oil filter. Where did that stuff come from? I don't know, but it scares me to
think that it came through
the full flow oil filters. Charlie Sims
of GCF says that it is normal to find such stuff the first time the bypass
filter is changed, but if it is ever seen again, there is a big problem. That's a comfort for my engines that are now
protected with the bypass oil filters, but what about my other engines?
I installed the Cummins 6BT
in my pickup with the intent that it would be the last pickup I would ever have
and the last pickup engine I would ever buy.
Was the same kind of junk running around in my 6BT? I don't know, but I decided to install a
bypass filter on it for protection.
While thinking about this,
I looked at the specifications for the 6BT and discovered that the oil bypass
valve opens at 60 psi. I have a real
mechanical oil pressure gauge and started observing it during the operation of
the engine. In outdoor temperatures
between 50 and 75 F., when the engine is started, the oil pressure increases
and remains near 70 psi at
moderate RPM for a
considerable period of time. Then the
oil pressure decreases and stabilizes at about 50 psi. During the time the oil pressure is above 60
psi, part of the oil circulated through the engine does not go through the full
flow oil filter. My oil is 15W‑40;
suppose it was straight 40 weight?
I don't have a
specification indicating when the oil bypass valves on my other engines
open. But I wonder what kind of
unfiltered junk is circulating in them at engine startup. The generator adds the complication that
upon startup, the engine runs at full operating speed ‑‑ 1800
RPM. It is commonly held that major
wear occurs at startup. Could the
circulation
of unfiltered oil be a part
of that?
These two discoveries, for
which I have no answer, have changed the equation for me. I now believe that installation of a bypass
oil filter should be considered for any engine from which long life is
desired. I would not put one on an auto
I was going to trade every 3 years, but I would put one on a boat I expected to
keep for 10 years. Because of the
startup situation, a bypass oil filter may be more important to recreational
start‑and‑stop trawler use than to the commercial long‑running
use. I will not argue with you if your
conclusions differ from mine.
During the summer, I'll put
a lot of miles on the 6BT under major loads. Since it is an engine used in a
lot of trawlers, I'll give brief reports of the results of the bypass filter
operation from time to time.
CaptnWil