Trying to breathe life into an engine I've acquired just for the fun of it. I know it's a '62 engine and I'm told it's from an Oval Window but then I was also told it was working when removed from the car only to find an exhaust valve head lodged in the piston head so I'm sceptical about any other information they gave me.

Anyhow,

Whilst cleaning up the pistons and rings it has come to my attention that each of the oil compression rings has no expansion coil or expansion spring - they are just solid plastic and don't even have an internal grove that might accommodate an expansion spring. Any other piston I've seen (not that that's many) has always been multipart and had an expansion spring on the inside.

Was there a time when these rings were just one piece with no expansion element, does any one know. Is this something I don't need to be concerned about? What do these oil rings do?

Rusquel

The oil ring on my 1200 was just a single piece bit of metal, until I replaced it with a new three part type made by Grant.

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Hi
the original rings are one piece and their job is to allow just enough oil through into the cylinder bore but not so much that the engine smokes, piston rings have to be fitted the correct way up as they typically have a chamfer that is to say the sharper edge points towards the bottom of the piston skirt so oil is scraped down the bore back into the crankcase not up the bore to the head, typically if you have an engine apart you fit new rings as they do wear out, and weirdly I have a box of rings I want to flog,Bill.

Thanks Bill, that's very useful and puts my mind at rest.

At the moment it's just a project/model engine so I can figure out how the darn things work (and it's been fascinating) so I'm just going to stick with the current rings but if I do ever get round to finding a rolling chasis/body that I can stick it into then I probably will change the rings, along with the pistons and bores.

Does that box of rings that you have contain any 77mm ones for a 1200 engine?

Hi
what I have is a box full of NOS piston rings and their various part number tags but the tags are not with specific ring sets, The last triumph or LT gave me the dimensions of his ring set and I definitely had those, I will take a look and see what I have, Bill.