page_title: Connecting rod
section_title: Failure during operation
hierarchical_section_title: Connecting rod / Internal combustion engines / Failure during operation
caption_attribution_description: Picture of a broken piston and connecting rod from a scooter. DR Racing Parts 65 cc piston, standard Suzuki Katana AY50 connecting rod (Morini two-stroke engine).
context_page_description: A connecting rod, also called a con rod, is the part of a piston engine which connects the piston to the crankshaft. Together with the crank, the connecting rod converts the reciprocating motion of the piston into the rotation of the crankshaft. The connecting rod is required to transmit the compressive and tensile forces from the piston, and rotate at both ends.
  The predecessor to the connecting rod is a mechanic linkage used by water mills to convert rotating motion of the water wheel into reciprocating motion.
  The most common usage of connecting rods is in internal combustion engines or on steam engines.
context_section_description: During each rotation of the crankshaft, a connecting rod is often subject to large and repetitive forces: shear forces due to the angle between the piston and the crankpin, compression forces as the piston moves downwards, and tensile forces as the piston moves upwards. These forces are proportional to the engine speed (RPM) squared.
  Failure of a connecting rod, often called "throwing a rod", is one of the most common causes of catastrophic engine failure in cars, frequently driving the broken rod through the side of the crankcase and thereby rendering the engine irreparable. 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.
caption: Top half of a failed connecting rod
exif: {"Image ImageDescription": "SAMSUNG DIGITAL CAMERA", "Image Make": "Samsung Techwin co., Ltd.", "Image Model": "Digimax A502", "Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Paint.NET v2.72", "Image DateTime": "2006:12:17 22:17:21", "Image YCbCrPositioning": "Co-sited", "Image ExifOffset": "262", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail Orientation": "Horizontal (normal)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "738", "Thumbnail JPEGInterchangeFormatLength": "2673", "Thumbnail YCbCrPositioning": "Co-sited", "EXIF ExposureTime": "1/30", "EXIF FNumber": "7/2", "EXIF ExposureProgram": "Program Normal", "EXIF ISOSpeedRatings": "200", "EXIF ExifVersion": "0220", "EXIF DateTimeOriginal": "2006:12:17 22:16:52", "EXIF DateTimeDigitized": "2006:12:17 22:16:52", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "2", "EXIF ExposureBiasValue": "-1", "EXIF MaxApertureValue": "18/5", "EXIF MeteringMode": "CenterWeightedAverage", "EXIF LightSource": "Unknown", "EXIF Flash": "Flash fired", "EXIF FocalLength": "29/5", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "2560", "EXIF ExifImageLength": "1920", "EXIF RelatedSoundFile": "", "EXIF FileSource": "Digital Camera", "EXIF SceneType": "Directly Photographed"}