King’s Sledge talks race engines in PRI, IMIS videos

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King’s Sledge talks race engines in PRI, IMIS videos

King Engine Bearings has released the video of a standing room only technical seminar conducted at two race industry trade shows in December, 2011.

Ron Sledge, King’s performance and technical manager, presented "Race Engine Bearing Lubrication, Clearances & Tolerances” at both the Performance Racing Industry Trade Show  (PRI Show) and International Motorsports Industry Show (IMIS) events.

The hour long presentation is now available to view, free-of-charge at

His seminar looked at bearing performance considerations for racing applications, including: oil viscosity, oil type (synthetic vs. mineral), oil pressure and temperature, proper bearing clearances, proper surfaces finishes and bearing assembly tolerances.

Sledge talked about the importance of wall thickness. "Inconsistent shell-to-shell bearing wall thickness can have a negative impact on clearances between the bearing and the journal on main and connecting rod bearings," explained Sledge. He said that common tolerance for wall thickness at the crown varies by up to .0005” (.00025” per shell).

"King Engine Bearings sets a higher standard of controlling the wall thickness, narrowing the average variation to .0002” (+/- .0001” per shell) from the target dimension," said Sledge. "We call this 'Bull’s Eye Tolerance.'”

For more information visit

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