Editing Rocker arms
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===Stamped steel=== | ===Stamped steel=== | ||
A mainstay of OEM engines. They're cheap to produce and perform adequately, although in serious competition and high performance applications they leave a lot to be desired. The ratio is often less than advertised, the ball pivot like used by Chevy and Pontiac are prone to wear and friction. | A mainstay of OEM engines. They're cheap to produce and perform adequately, although in serious competition and high performance applications they leave a lot to be desired. The ratio is often less than advertised, the ball pivot like used by Chevy and Pontiac are prone to wear and friction. | ||
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===Roller tip=== | ===Roller tip=== | ||
The roller tip only rockers are mostly a gimmick. Their only real advantage comes not from the roller tip (which by one estimate would need to be a 2" diameter roller to duplicate a stamped steel rocker), but from the more accurate ratio; stock stamped steel rockers often have less than advertised ratios and this means less than advertised lift, and a good chance of less peak performance. | The roller tip only rockers are mostly a gimmick. Their only real advantage comes not from the roller tip (which by one estimate would need to be a 2" diameter roller to duplicate a stamped steel rocker), but from the more accurate ratio; stock stamped steel rockers often have less than advertised ratios and this means less than advertised lift, and a good chance of less peak performance. | ||
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===Roller trunnion=== | ===Roller trunnion=== | ||
− | [[File:LS7 stock rocker arms.jpg|thumb|400px|Gen 3/4 Chevy rockers]]A roller trunnion is the best improvement that can be made to a rocker arm using a design that permits it. As an example, Chevy Gen 3 and 4 engines use a roller trunnion | + | [[File:LS7 stock rocker arms.jpg|thumb|400px|Gen 3/4 Chevy rockers]]A roller trunnion is the best improvement that can be made to a rocker arm using a design that permits it. As an example, Chevy Gen 3 and 4 engines use a roller trunnion without a roller tip. These rockers are very efficient and represent the state of the art as far as OEM rocker arms go. These rockers can be upgraded with a replacement trunnion bearing assembly and are then good for high performance use beyond what the stock bearings could take. <br style="clear:both"/> |
===Full roller=== | ===Full roller=== | ||
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[[File:SA vs non sa rockers.jpg]] | [[File:SA vs non sa rockers.jpg]] | ||
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==Converting a non-adjustable valve train== | ==Converting a non-adjustable valve train== | ||
Old and new engines have both used net lash or non adjustable rocker arm arrangements. The latest Chevy engines are now among these; for years the Chevy V8 enjoyed the benefits of an adjustable stud-and-rocker setup but unfortunately that's gone by the wayside. | Old and new engines have both used net lash or non adjustable rocker arm arrangements. The latest Chevy engines are now among these; for years the Chevy V8 enjoyed the benefits of an adjustable stud-and-rocker setup but unfortunately that's gone by the wayside. |