Traditional journal bearings for internal combustion are of the tri-metal type. This type of bearing consists of a steel backing, a hard middle layer and a soft top layer. Typical soft bearing materials are: lead, tin, zinc, or alloys of these metals while typical hard bearing materials are: Aluminium-tin; lead-bronze; copper-lead. The soft top could comprise of three layers, providing five metal layers.

Journal bearings operate between the extremes of no lubrication on the one hand, to thick-film lubrication on the other. Therefore, bearing material must possess Read more…

FATIGUE AND WEAR IN A JOURNAL BEARING (during start-up and boundary lubrication)

When two bodies are pressed together contact stresses occur. The results of the work done in this area are due to Hertz and are referred to as Hertzian stresses. Two special cases of hertzian stresses are: contacting spheres and contacting cylinders. An example of contacting spheres would be a single row ball bearing, with a single ball contacting the inner surface of the inner or outer race. An example of contacting cylinders would be a Read more…

The purpose of a bearing is to support a load. Deflection of the journal within the bearing can adversely affect the load carrying ability of the bearing. This deflection can be greatly reduced by increasing the diameter of the journal and decreasing its length. This results in a short bearing with a consequential greater flow of oil out of the ends of the bearing. This outflow of oil transfers heat from the bearing and helps to reduce the bearing temperature.
The factor which controls the length of the bearing to the journal diameter, is known as the L/D ratio. Read more…

For all of its engine bearing needs in NASCAR Camping World Truck Series (CWTS) engines, PME Engines of Mooresville, North Carolina has researched heavily to meet its main and rod end requirements.

On a mile-and-a-half oval like Chicagoland Speedway, where the CWTS raced the final weekend of August, PME owner Mark Smith acknowledged that he is “always fighting temperatures because they never lift here. They’re running wide open throttle all the time, so the temperatures are always up and you always have Read more…

“It is always a battle for our engine bearings,” says John Medlen, tuner for John Force Racing Funny Car driver Mike Neff in the NHRA’s Full Throttle Drag Racing Series. “Their survival is predicated on the cylinder pressure applied to the bearing and the manner in which we see a rise in that cylinder pressure. We have to look at the pressure curve,” he said.

In all the nitromethane-burning NHRA classes, it’s “okay to have a high and long cylinder pressure curve Read more…

SKF Automotive is well regarded for its work in NASCAR Sprint Cup Series competition, where it produces camshaft bearings used by major teams in this upper level racing.

Still, the Plymouth, Michigan manufacturer has interests beyond the scope of recognized motor sport. SKF is one of the major backers of the local University of Michigan solar-powered race car. The University of Michigan solar team’s Continuum competed in an 1800-mile race across the Australian outback in 2008

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In company with the small end bearing there’s no more hard working bearing surface than that found in the big end of high performance gasoline and diesel race engines.

In a good example of a reverse technology flow - series production to racing - bearings originally developed to cope with extreme cylinder pressures found in the latest generation of high speed passenger car and commercial diesel engines have found their way into Formula One and sport car engines.

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In NHRA professional drag racing, main and con rod crankshaft journal bearings are among the items that can make or break a run. It stands to reason that when a team finds something that works well for them, they are inclined to leave well enough alone.At John Force Racing, Dean ‘Guido’ Antonelli is one of the crew chiefs for the quartet of Funny Car teams. His prime requirement is tending to Ashley Force Hood’s Ford Mustang Funny Car.Occasionally, when Antonelli misses on the tune-up at the track, he will “Burn the bearing babbit off but won’t hurt the crankshaft,” because of the enhanced MAHLE Clevite bearings he currently uses. Read more…