Talk:Shock cooling

Latest comment: 11 years ago by Jgrosay in topic More precise definition

Needs editing

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This page needs further editing for grammar/spelling, accuracy, citations, opposing arguments with citations in favor of the traditional view of shock cooling, and possibly a discussion on using cowl flaps to control cooling. —Preceding unsigned comment added by 131.204.141.171 (talk) 21:00, 18 October 2007 (UTC) --Jgrosay (talk) 12:17, 2 January 2013 (UTC)Reply

More precise definition

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The problem is as stated in article; if after a long time level flight or climbing that requires a high power output from engine, the heat production of engine is suddenly reduced, the outer part of cylinder under low load, but at high rpm or high air flow cools faster than the piston, thus it contracts to a size lesser than the original one, no longer fits the size of the still hot piston, and engine seizure or other type of failure may result from the mismatch in size between cylinder and piston. Some two-stroke engines had a similar problem when installed in cars where no fan cooling was provided for the engine, thus suffering very big differences in working temperature depending on whether the vehicle was in an arrest, for example at a traffic light, or running at any speed. The engine used in the tiny Voisin car, Bi-scooter, had a cylinder head with a large wing, filled with lubricating oil, that acted as a buffer limiting fast engine's head temperature changes, blunting it, either overheating during an arrest, or a putative shock cooling hard to happen, if ever, in this engine. An approach for some of the thermal inertia problems in air-cooled engines may be the use of a somehow thick oil-filled jacket between the inner part of cylinder and the outer where fins are located, this won't reduce the heat transfer, but may give the engines so arranged some of the advantages of liquid cooled engines, as more stable temperatures, and also the advantages connected to the time in reaching the ideal working temperature, and in maintaining it, a substance with high inherent heat and slow in increasing or decreasing temperature may minimize this danger, that seems having been suffered by pilots of airplanes with air cooled engines during WWII.--Jgrosay (talk) 13:51, 4 January 2013 (UTC)Reply