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Re: Are piston rings absolutely necessary?
Re: Are piston rings absolutely necessary? -- D.Taggert	Post Reply	Top of thread	Forum

Posted by: james25 ® 04/19/2006, 08:33:55 Author Profile eMail author Edit

yes it is plausible but piston rings are there to keep a tight seal between the piston and the cylinder wall therefore increasing horsepower and fuel efficientcy but i have seen a motor with a special type of piston with a little groove poking out of the piston to replace the piston ring

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Re: Are piston rings absolutely necessary?
Re: Are piston rings absolutely necessary? -- D.Taggert	Post Reply	Top of thread	Forum

Posted by: Kelly_Bramble ® Administrator 04/19/2006, 08:29:12 Author Profile eMail author Edit

Interesting question, I am aware of a miniature compressor which does not use piston rings. The compressor is used in a tiny refrigeration unit used to cool electronic components. I don't know what the materials where, however I do know that the tolerances where very tight. Clearance between the piston and sleeve was .0002" nominal. The answer is "yes" it is possible. The question you should realy ask is "is the design adequate for the intended application? In any evaluation of a technology you should test, test and then test some more.

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Re: Are piston rings absolutely necessary?
Re: Re: Are piston rings absolutely necessary? -- Kelly_Bramble	Post Reply	Top of thread	Forum

Posted by: randykimball ® 04/19/2006, 23:23:52 Author Profile eMail author Edit

"model" airplane engines (that I have experienced) do not have rings. However, as diameter of the piston increases the thermo expansion ration begins to make it necessary to fill the compression gap between the piston and the cylinder with some device as this gap size increases to prevent interference fits at idle through overheated temperatures. To truly (to me) design a reasonable sized internal combustion engine without some sort of compression rings one would need to design a piston and cylinder with nearly identical thermal expansion. This is tricky if the piston has a rod bearing and a solid crown with support ribs. Also, many modern pistons are usually designed not round (because of the above different thermo masses) until they are at operating temperature. The worst suggestion of your lifetime may be the catalyst to the grandest idea of the century, never let suggestions go unsaid nor fail to listen to them. Modified by randykimball at Wed, Apr 19, 2006, 23:26:30

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