Re: 1952 250 Mayfar 327 ci

Posted by Rusty O\'Toole On 2008/8/10 21:58:58

From the Caterpillar Company's official web site.

According to this motor oils contained natural detergents until a change in refining methods about 1930.When they discovered that the new oils were ruining motors, they quickly started putting detergents back in. So detergent oils date to the early 30s.

"Just as diesel power was beginning to take hold, the world caved in on the young industry. Engines that had gone 3,000 hours without ring sticking or liner scuffing were suddenly dying at 300 hours. As the piston rings got stuck in their grooves, the engine lost compression. As the engine lost compression, it lost power. Eventually, there would not be enough compression for ignition and the engine would not run at all.

The engine manufacturers blamed the oil companies and the oil companies blamed the engine manufacturers. It took several years before everyone realized that a new refining process introduced in the early 1930's had removed naturally occurring detergents from the crude oil. With the detergents gone, there was nothing to inhibit the formation of combustion by-products in the ring grooves, which eventually led to the ring becoming stuck in the groove and not sealing. At this point, a serviceman would have to pull each piston and scrape off the accumulated sludge after applying a boiling bucket of chemicals to the piston. Caterpillar knew there had to be a better way. In discussions with the Shell Oil Company, a chemical was identified that did not require boiling to remove the sludge. It was a chemical detergent. One enterprising serviceman started putting the chemical in the engine crankcase just prior to each oil change. As he drained the oil, he also drained the dissolved sludge. This process quickly evolved into adding small amounts of the detergent to the oil to replace the natural detergents that had been present in the crankcase oil just a few years before. From that point, the Shell Oil Company started adding the detergent during production back at the refinery."