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More Enginelabs - this time making piston rings


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#1 mariner

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Posted 15 November 2022 - 08:23

Another EL video, not quite as good as some but nice to know how those rings get made 

 



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#2 Magoo

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Posted 25 November 2022 - 13:48

One of the things that made cast-iron piston rings so successful was/is the way they were manufactured. 

 

They start with a centrifugally cast gray iron cylinder, much like a bore liner, centerless ground and then slit and sliced up into rings like a loaf of balogna, then finish ground.

 

This produces a remarkably uniform and dimensionally stable ring with great sealing and wear properties. 

 

Diesel rings are much the same but cast in ductile aka nodular iron instead of gray iron. 



#3 Lee Nicolle

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Posted 28 November 2022 - 07:38

Cast iron rings are ok in tired old gunkers for a rebuild. Used car engines. They seal well  for a period then wear out,, both the rings as well as the bores and pistons. Some use them in engines that see a lot of dirt. Speedway and Off road

A chrome ring is great in a new bore with a fine finish and will last a long time. Chrome ring with moly is better. 

Though these days there is so many styles of rings for race engines. I am out of date and hope the manufacturers ahve given me the correct parts for the application.

Though,, overhauling old engines and the gaps out of the box are worse than the old ones that came out. 4 thou an inch gap was always the 'safe' limit. These days it seems like 6 thou. Even on new bores. They can be a big leak!

And look at these turbo drag race engines, like a steam train on the line, and some seem to be during the run. 



#4 Magoo

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Posted 30 November 2022 - 16:22

The classic chrome ring is chromium-plated cast iron. 

 

Recent steel and stainless steel rings are made from wire, which is fast and precise.