I scored an Subaru EA81 engine that has been bored out to take 0.50mm Pistons just

need  to know what size rings I should be using.

Edited May 4, 2025May 4 by gazza01
no edit

Contact these folks and ask if the have .50 rings. Also, you can look thru all the other vendors on ebay to see if someone sells the set. I tend to steer away from DNJ parts, As they are cheap chineseum stuff, but I've had good luck with Hastings and NPR

https://www.ebay.com/itm/286535946018?fits=Year%3A1984|Engine+-+Liter_Display%3A1.8L|Trim%3ABase+Hardtop+2-Door|Model%3AGL|Make%3ASubaru|Submodel%3ABase|Engine%3A1.8L+1781CC+H4+GAS+OHV+Naturally+Aspirated&_skw=Engine+Piston+Ring+Set&itmmeta=01JTGGCDK5QCYY56G3JP27C2G5&hash=item42b6df8f22:g:GRMAAOSwGV1n8-L7&itmprp=enc%3AAQAKAAABIFkggFvd1GGDu0w3yXCmi1dVY6P5gatqhuRHuVG4ciQApiO91CmKZ1GKhjuDRTL1uR8hyiSb5sbsItgmuoKoBQlCzg23eI%2BhpPrJpzKKCP4lOjPOopLM3kluSYyR%2Fc76VCR13ECk%2B7T6Iy3QfGbavPNaOIG1rLJ6m3eAYuK%2FEWNMUZLPY%2Bo%2Bud6v3Uzwmo58K%2Fg964pFpDXHq7E1XZOljK2MhX8HT5DvSWlpcB9UOcbDjoG0ai3Pr8rb1KaI%2B%2FbGScHm1YJZ326VlfMnXDQFMyh77DAvU1C%2BkXpEYnGJVNmYjI3XcOORaUDrio5A%2BiGczM9gGwQUSRqfW3TEXNW3jqgRq3cfxaRbszs1W4rijv825AENgRfUdu6o5Pr7mVfSUw%3D%3D|tkp%3ABk9SR-DZsZDUZQ

That’s maximum as I know it. And I can’t recall seeing 50 over.

Not many folks have bothered at that point. I cannot recall anyone with a 50 over EA anything. 
 

Good luck with it. 

92.50 mm, either 2.0mm 1st & 2nd or 1.2mm 1st & 2nd rings, depending on engine/piston.

https://hastingspistonrings.com/catalogs-cross-reference/

https://hastingspistonrings.com/wp-content/uploads/2023/05/asian-catalog-americas.pdf

https://www.ebay.com/itm/187161728886?fits=Make%3ASubaru&_skw=subaru+92.50+mm+EA81+piston+rings&itmmeta=01JTH36YHWEVD0QXGV0YXQQ7AS&hash=item2b93b55776:g:bS0AAeSw-8loBnk~&itmprp=enc%3AAQAKAAAA4FkggFvd1GGDu0w3yXCmi1ds6hQQs5C0Aavw5a6pUKCItZ201Ll3mNujqNg%2FsDD%2FLkBJ7WFKlwnHz4MCZCGppX%2FDPCDO2CTW%2Fvzc4HYFSx3w9SyT4GZCR6X%2BQAOqWhGGlpjyupNBUSt2bDQiHwVVQrWC8j3PomzHL%2FC3cd7lS0b6r1WQN%2BzytOPdLZcBBAbGI79artDEqCIFjPgS20GvkOHTQBPMLEpKJg8wrV0ut6%2FgSomiZDBl%2BETktnc2BjmLNBg0pz0GA6%2FPT4uRkWL1yd3ExzklURJ2K4Rak9MQpInT|tkp%3ABk9SR47pm6PUZQ

Contact seller importengineparts on fleabay for NPR rings.

YMMV

 

Edited May 5, 2025May 5 by czny

If you really love the EA82 you could have the engine sleeved. 50 thou over seems a lot. I thought 40 thou was as far as they went with new rings and pistons for the EA82. I could be wrong, I only ever rebuilt one before I really learned about them. 

Cheers 

Bennie