SNAKE OIL CHRONICLES - Second Iteration

By: Karl Denninger

Here we go again!

A couple of years ago I wrote an article I called the "Snake Oil Chronicles", detailing my experience with the Algae-X "fuel conditioners."

Now I've been asked what I might think about the "Diesel Tex" units, which purport to do the same thing...... so, two units in hand, I have accepted the chellenge under the same terms, specifically:

• I will report what I see and find, irrespective of what happens. No "pulling my punches" and no "editorial review." What you see is what happened.
• This page stays up, whether its "good or bad" according to whoever would like to applaud (or complain)

Diesel Tex can be found on the web at http://www.dieseltex.com; here is a picture of the various units available:

Fair warning and disclosure - I do not work for DieselTex in any capacity, and have no financial interest in the company.

My methodology of testing will be as follows:

• I will pull and discard ALL FOUR RACOR filters, replacing them with new filter elements.
• At the same time, I will ENABLE the DieselTEX filter on ONE engine chosen at random (by flipping a coin). I can tell you from examination today that both RACORs that are in service right now appear identically fouled and are black in color; there is no detectable difference between the two.
• I will run a trip, and pull the filters.
• If there is no appreciable difference, I will continue to run a few more trips until I have accumulated approximately 20 hours on the units. I will then change the filters AGAIN, and continue.
• IF/WHEN I see an appreciable difference over a few trips, I will change the dirty filter, leaving the clean one in place. I will then SWAP the unit that is in active use; that is, if the active engine is the port, I will change it to the starboard, and see if the condition of the filters moves from one side to the other.
• If it appears that the unit IS responsible for the difference, I will run for a while with BOTH units enabled, then turn them OFF and see if the filters once again foul.
• FINALLY, if it appears that I can run with clean filters indefinitely (or close to it) on the DieselTex units, I will then swap to 10 micron primary filter elements (from my current 30 microns) and see if THOSE remain clean. That is an extreme test - I cannot run anything finer (e.g. 2 micron) in the RACORs as Detroit specifically recommends against it.

The configuration of the fuel system and specifics of the test environment are:

• I have a dual RACOR filter system. Fuel comes from a tank selector in the lazarette of my boat, then to a shut-off valve in the engine room. From there it goes to a "Y" valve which allows me to direct fuel to either of the two RACOR filters mounted for each engine (4 filters total.) In the outlet of ONE of these ports I have installed the DieselTex unit; thus, when the forward RACOR is selected for filtration, the DieselTEX is inline - when the aft RACOR is selected, the DieselTEX is bypassed.

• The engines are Detroit Diesel 6V92TAs, 500SHP each, in a 1985 Hatteras 45C. Fuel tanks are fiberglass; primary lines are copper thick-wall, with Aeroquip hose from the selector valves onward to the engines and for distribution to the fuel rails and ultimately the injectors.
• The boat has two fuel tanks, with a selector manifold at the front wall of the cockpit allowing selection of the supply and return to and from each engine independantly. In normal operation and for the duration of this test the port engine will draw from and return to the port tank, and vice-versa.
• I normally run Racor's Fuel Conditioner+ in the recommended concentration for cetane and lubricity improvement, and intend to continue doing so for the duration of this test. No other chemicals (e.g. biocides, etc) are normally or will be used.
• The normal state of the RACOR elements results in them reaching the recommended restriction level in approximately 100 engine hours from new. A black colored fouling throughout the element is evident within a few engine hours of element replacement; the fouling is not "slimey" and no evidence of biological contamination is present in either fuel system. The fouling appears to be from asphaltene drop-out.
• The boat carries 590 gallons of fuel, and my usual operational regime requires approximately three to four weeks to burn through a tank's worth. We typically run once a week, sometimes a bit more often, usually for diving (but sometimes for fishing), and are out all day, with 6-8 engine hours being clocked.

Here's the chronology, recorded as each event occurs, and documented with photos when appropriate...

8/26/2004 - Installed one DieselTex 503 unit in the forward RACOR feedline for each engine. Each is an apparently solid block of aluminum with a clear "parting line" in one end; the manufacturer claims that they cannot be disassembled, however. The units were installed without incident requiring only one 1/2" pipe nipple in addition to the plumbing already on the boat. The installation is definitely "temporary", as you'll see from the pictures to follow - if I keep 'em, they're going in permanently mounted right on the RACORs.

9/1/2004 - Have run two trips. The port engine was the one which won the "coin toss" when the installation took place, and thus, it is the one which is enabled. The Starboard engine is running without the unit inline. There is a MARKED difference - much larger than I saw with the Algae-X units (!) I didn't expect this, but here's the evidence for you in living color...

PORT Engine (unit ENABLED):

Note that there is some darkening of the element, but not a whole lot.

STARBOARD Engine (unit DISABLED):

This element is black, as were BOTH when they were changed before the test began.

10/31/04 - The boat has not been run all that much, due to Ivan. We have had to run away from the storm, run back, and then put on a couple of trips since in the gulf - but no major operating hours. Total operational hours on the motors in the last two months as less than 20 - which is unfortunate, as it should be expected to color the results.

Oh well, I promised to report what I have, and here 'ya go. Here are the port and starboard filters at present - remember, port has the unit enabled, starboard has it turned off. Both filters are, to the eye, equally fouled at the present time, but neither shows enough restriction to justify a change of the elements.

Port filter

Starboard

Developing as evidence continues to build..... hopefully we can get enough hours on the filters and units in the next few months to draw some valid conclusions, and don't end up waiting until spring....