This is an example SPEEDiagnostix report sheet from this test. It shows the type of results you can expect as part of the evaluation. Any warning signs are immediately highlighted in yellow or red. If everything is good, the check marks are in green.
Neither is available as an off-the-shelf oil with this specific blend of additives, but they both are representative of high-zinc and high-phosphorus lubricants. Speed chose a lower viscosity base-oil which would intentionally decrease the oil film thickness and increase potential bearing contact and wear.
As you can see from the results chart, the differences are measured in as little as single-digit parts-per-million (ppm) numbers. In order to ensure these numbers are accurate, Speed also performed a flush procedure between each of the four tests. This involves draining the test oil, removing the Wix oil filter, and refilling with Driven’s break-in oil BR30 along with a new filter, and then running the engine for 30 minutes, including two full-power dyno runs. Then the break-in oil is drained and the filter removed and the next oil is added. This exact same procedure is repeated when the bearings are changed. This ensures that the results will be as accurate as possible.
This photo shows the uncoated XP rod bearing on the right after running loaded for over three hours using a 5w20 conventional oil. The same test with the same oil was performed on the King pMaxBlack XP bearing on the left. The wear reduction is obvious.
The accompanying results chart also lists the additive package. Zinc and phosphorus (ZDDP) are anti-wear additives that most enthusiasts are familiar with. Molybdenum and boron are friction-reducing additives while calcium is employed as a detergent. These were the main additive package ingredients for both the conventional and the synthetic oils so that the only difference was the base oil.After the first test sequence with the petroleum-based oil, Shavers’ engine builder, Keith Chrisco, removed the first set of bearings and added a second set of identical XP bearings. He then ran the engine using the mPAO-based synthetic 5w20 oil.
The third test involved switching to a new set of King’s pMaxKote rod and main bearings, but returning to the traditional mineral base 5w20 oil. The fourth and final test saw the installation of another new set of pMaxKote bearings run this time with the synthetic oil. This created a comparison of coated and non-coated bearings with traditional and synthetic engine oil.
These are five of the lower, uncoated XP bearings as they were pulled directly from the engine after running the test using conventional oil. As you can see, there is considerable wear.
The evaluation criterion for each test would be a comparison of the wear count of the different metals (in ppm) by analyzing the oil drained from each test. The testing was performed by
SPEEDiagnostix, a new oil evaluation company using the same metal spectrometer techniques as is used in current Formula 1 racing.
The best way to really load these bearings and ensure that the test schedule would be both consistent and survivable was to pull the aforementioned small-block Chevy down to an extremely low RPM with a high load. The
SuperFlow dyno was able to pull this little Chevy down to 1,450 rpm for a total of three hours and fifteen minutes for each of the four tests. During this time, the low-RPM test was interrupted so the engine could also be subjected to a complete test up to just past peak horsepower a total of 14 times. Oil and water temperature was also closely monitored.Instead of horsepower, this test was all about survivability. In the attached chart, we have condensed a much more expansive report down to the wear results. The important wear materials are iron, copper, lead, tin, and aluminum. Both the standard and coated King tri-metal bearings are made up mainly of copper, tin, and lead so these would be the major elements that would indicate bearing wear. Aluminum would originate mainly from the pistons while the iron would likely be sourced from the cylinder walls.
While the trace material numbers are relatively low PPM counts, it is the differences from each test that is compelling. Let’s start by explaining each category in the results sheet. The Oil Type indicates the type of oil – either conventional or synthetic. The Bearing Type indicates whether the bearings were coated or uncoated. The Oil Viscosity Index is a rating system applied to engine oil that indicates how much an oil viscosity changes over a wide temperature range. The higher the number, the more thermally stable the oil is over a wide range of temperature. This means that as the oil warms up, it loses less viscosity.