Years ago there were a number of additives on the market containing “Teflon” or PTFE (Polytetrafluoroethylene) the most well known was Slick 50. While PTFE is a wonderful anti friction coating the inclusion of it in a powder form in motor oil has never been proven to reduce engine wear, in fact the FTC sued the mfg and has stopped them from making advertising claims they once made. Fact is since it is so slippery, as small suspended particles it will not bond to anything particularly suspended in oil. If the particles are of large enough size so they could have any significant affect they would not pass through the filter. At one point DuPont the maker of PTFE sold under the trademark Teflon actually stopped selling it to the makers of Slick 50 stating it was not suitable for use in motor oil. The makers of Slick 50 actually ended up suing DuPont to re-gain access to Teflon powder.
Early on a common demonstration method for Slick 50 was add the product to the crankcase, run the engine for awhile, drain all the lubricant, restart and run the engine again. The common engine to use was the good old horizontal shaft old Briggs & Stratton engine which has been proven to run just fine w/o oil for an extended period. Reportedly B&S became aware of someone purchasing large numbers of their engines, modifying them with a “glass” side cover so people could verify that there wasn’t any oil in the engine. So they performed their own test. Two brand new engines were pulled from the assembly line, engine A was run for 20 hours with the factory fill while engine 2 was run for the same length of time with Slick 50. After the 20 hour break-in/treatment period the oil was drained and both were run for another 20 hours and then disassembled. Both engines showed a similar amount of wear on the crank and rod while the engine “treated” with Slick 50 was noted to have cylinder wall scuffing that the control engine did not. This was early on when Slick 50’s base oil was reported to be a straight 50 wt and the size of the PTFE particles was quite large. The B&S engineers of the day speculated the damage could have been caused due to oil starvation caused by the wrong viscosity, or the large chunks of Teflon, causing the rings to stick.
All of that said there is a place for Teflon in an internal combustion engine and that is properly applied to the skirts of pistons. In fact that is part of the reason that the Ford 4.6 is known for its durability.
There are also a number of additives that contain, or did contain, chlorinated paraffins. Chlorinated paraffins are actually a very old technology, dating back to the 1930s as one of the first EP or Extreme Pressure additives. It is a powerful anti-seize compound however it is also very corrosive attacking copper and materials that contain copper aggressively. This can damage many engines in Curbside Classics. For many years the primary construction of main, rod and camshaft bearings was the tri-metal bearing. That type of bearing consists of a steel backing, a layer of copper, and a layer of “babbitt”. Babbitt is actually a term used to describe a number of different alloys of “white metal” used as bearing material, some of which include copper. Many distributors also use bronze bushings to support the shaft and sometimes, but more rarely, distributor drive gears are made of bronze an alloy of copper.
One of common ways of demonstrating the “effectiveness” of Chlorinated paraffins is to use a dowel pin or roller bearing that is held stationary while another shaft is rotated against it at a right angle. Pressure is applied to the contact area with a torque wrench as a lever to show the force being applied. This is often referred to as the “Falex” test. Falex is a provider of testing services and produces a number of different machines to test lubricants and their effectiveness in preventing wear and the Pin machine is just one of them.
One the additives that used such demonstration techniques in the past was zMax and like the makers of Slick 50 they were sued by the FTC over unsubstantiated claims. One of the specific charges was that they purposely left out results of independent tests that noted the increase in corrosion caused by the product and omitting other negative test results.
Stay tuned for the final installment of Crankcase Additives where we will discuss ZDDP an important ingredient in motor oil used in our Curbside Classics and many not so classic engines.
As always send any and all questions to CurbsideClueless@Gmail.com
On an semi-unrelated note, but one of a great passion of mine. Our robotics team has completed this years 45 day build season and our robot is in the bag. That means we are entering the six week regional competition season. We compete in the FIRST FRC (First Robotics Competition) League. Those competitions start this weekend. If you have any interest in technology, engineering, or our future generations you owe it to yourself to check out one in your area, particularly if you have school age children or grand-children. A complete list of events can be found here, the events are always open to the public and free. For those in the greater Portland area our team will attending the Autodesk Oregon Regional March 8-10th at the Portland Memorial Coliseum. Stop by our pit I’d love to meet some of our readers, and contributors from the area in person. Ask for me and if I’m not in the pit at the time someone there will know how to track me down. For the many Seattle area readers don’t worry we’ll be there too. Saturday is when the finals are, starting after lunch, but to get the full effect of touring the pits be there early. If you plan to attend shoot me an E-mail or make a note in the comments below.