Making piston rings.

[Nick_GParticipant @nick_g]

Posted by XD 351 on 18/04/2016 11:47:14:

Yes i feel this website could be more than just a forum and some advertising !

Ian

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I did not mean for this to be on this site. I meant for it to be a magazine special in ME's sister publication Model engineer workshop.

Nick

[John OlsenParticipant @johnolsen79199]

I wouldn't lap rings or a cylinder that they are to run in. The fine grooves left by honing or grinding hold a little oil which is better for the running in process. Full size cylinders used to sometimes get a hone after they became glazed and before putting in new rings. The idea with honing a cylinder is to get a kind of cross hatch pattern with the honing by moving the hone up and down as it goes round and round.

John

[I.M. OUTAHEREParticipant @i-m-outahere]

Posted by Nick_G on 18/04/2016 13:17:17:

Posted by XD 351 on 18/04/2016 11:47:14:

Yes i feel this website could be more than just a forum and some advertising !

Ian

.

I did not mean for this to be on this site. I meant for it to be a magazine special in ME's sister publication Model engineer workshop.

Nick

Ok so something like Model Engineers Workshop 101 tip tricks and techniques for the workshop ?

Ian

[I.M. OUTAHEREParticipant @i-m-outahere]

Posted by John Olsen on 18/04/2016 22:26:42:

I wouldn't lap rings or a cylinder that they are to run in. The fine grooves left by honing or grinding hold a little oil which is better for the running in process. Full size cylinders used to sometimes get a hone after they became glazed and before putting in new rings. The idea with honing a cylinder is to get a kind of cross hatch pattern with the honing by moving the hone up and down as it goes round and round.

John

The lapping process aids running in as it ensures that the OD of the rings make full contact in the engine cylinder as they have been fitted to a dummy piston and lapped in a dummy cylinder that is the same bore size as the engine cylinder the dummy cylinder has also been honed and a tapered leade machined in one end to aid getting the dummy piston and rings to be lapped into the dummy cylinder it is just a matter of lubricating then working the dummy piston back and forth in the dummy cylinder around 50 strokes then checking the rings . You should see a nice shiny surface around the OD of the rings if not lap again and any dodgy looking rings can be pegged in the bin , it just helps to sort the good ones from the bad before you install them in an engine , many rings in full sized engines are lapped at the factory that makes them.

The engine cylinder is honed as usuall not lapped .

Ian

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