Editing Connecting rod (section)

=== Failure during operation ===
[[File:Biella rotta per fatica.jpg |thumb|right|upright=0.75|Connecting rod that initially failed through fatigue, then was further damaged from impact with the crankshaft]]

During each rotation of the crankshaft, a connecting rod is often subject to large and repetitive forces: [[shear force]]s due to the angle between the piston and the crankpin, [[Compression (physics)|compression forces]] as the piston moves downwards, and [[Tension (physics)|tensile forces]] as the piston moves upwards.<ref>{{cite web |title=Causes of Failure With a Connecting Rod |url=https://itstillruns.com/causes-failure-connecting-rod-7260672.html |website=www.itstillruns.com |access-date=21 September 2019 |language=en}}</ref> These forces are proportional to the engine speed (RPM) squared.

Failure of a connecting rod, often called "throwing a rod", often forces the broken rod through the side of the crankcase and thereby renders the engine irreparable.<ref>{{cite web|title = What does it mean to "throw a rod"?|url = http://www.cartalk.com/content/what-does-it-mean-throw-rod|website = Car Talk|access-date = 2016-02-05|date = April 1990}}</ref> Common causes of connecting rod failure are tensile failure from high engine speeds, the impact force when the piston hits a valve (due to a valvetrain problem), rod bearing failure (usually due to a lubrication problem), or incorrect installation of the connecting rod.<ref>{{cite web |title=Preventing Connecting Rod Failures |url=https://www.enginebuildermag.com/2017/03/preventing-connecting-rod-failures/ |website=www.enginebuildermag.com |access-date=21 September 2019 |date=15 March 2017}}</ref><ref>{{cite web |title=How to eliminate connecting rod failures |url=https://www.hotrod.com/articles/ctrp-0311-connecting-rods/ |website=www.hotrod.com |date=November 2003 |access-date=21 September 2019}}</ref><ref>{{cite web |title=Probable Cause of Most Rod Failures |url=https://arcracing.blogspot.com/1999/07/probable-cause-of-most-rod-failures.html |website=www.arcracing.blogspot.com |access-date=21 September 2019 |date=1 June 1999}}</ref><ref>{{cite web|title = Emerson Bearing Extreme Applications |url = http://www.emersonbearing.com/news-articles/extreme-applications|website = www.emersonbearing.com |access-date = 2016-02-05|language = en-US}}</ref>
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