piston ring question

[beanbag]

Hey guys I have a quick question for you. I need to order some piston rings for my clasic uk 2001 impreza. My question is I have the option of 1.2mm 1.3mm or 3mm. I was told to measure the oil one which I have done which is the width though I want to order the correct ones but am unsure.

Any advice would be great thanks guys

[felix_19]

sure someone will be along soon to help bud, how come you need piston rings how many miles you done?

[beanbag]

I did about 250 miles and the bottom end went two days after buying it. Gutted was an understatement. I need to order the piston rings ASAP but unsure what measurements I need.

I'll get some pictures up soon

[beanbag]

http://s40.photobucket.com/user/beanbag1983/media/Mobile%20Uploads/20140729_211105_zpsda360a4c.jpg.html

Which way do I measure them. Never done it before so it's new to me but I wanna learn

[beanbag]

My engine is standard at the bottom it says the sizes any ideas guys

http://www.advancedautomotives.com/subaru-impreza-and-legacy-ej20-and-turbo-new-quality-piston-ring-set-1542-p.asp

[Tlag]

You need to measure the gap in the piston that the oil ring came out of. The oil ring is the one with what looks like corrugated metal in the middle. (It's also the one in that photo, if that's yours, then the 3mm is the one as that's showing 2.9mm)

If you are still unsure, ring advanced up and tell them the exact model of car you have and year. They are really helpful and will point you in the right direction.

[beanbag]

Tlag thanks for your speedy response. I thought it would be 3mm but I wanted someone else to clarify this for me. I know now how to measure them. I will get these rings ordered tonight

[beanbag]

Ok so I measured the gap on the piston where the oil ring sits and I'm now pretty confused as the feeler gauges seem to think this gap is about 2.6mm 2.7mm. Does this mean I need the 3mm rings as they will be slightly compressed when they sit on the piston ?

Regards Chris