Piston Ring Inspection.

sandyc

Hi folks Im new to the board and have recently sold my agricultural Subaru in favour of an Astra 2.2 Sri. 04 Plate with a Z22se Engine.
I am writing this with oily hands after removing the head from my engine due to that old chestnut of excessive smoking.
The car was burning oil on start up and occasionally under heavy acceleration.
Now that the head is off I have started cleaning up the pistons and the block before I re build the head.
I have checked the pistons for movement to try and assess the condidtion of the rings and number 1 appears to have a fair bit of movement.
I'm thinking it may be wise to do the rings while the head is off however I dont really want to have to go to the extra expense.
Im just wondering how much movement is permissible.

sdbutler10

Th mate if it smoking during start up and under heavy foot down rings prob have worn, what's the milage?
It's worth chaining the rings not to bad and I got a set for under z£70

BURT150

Im not sure how much tolerance there is but for the sake of it just change them.

Understandably its more expense but if you do all that work and it still smokes after the rebuild you wont be a happy bunny 🙁

Have you also checked the valve guides for run out. new stem seals are a temporary fix if the valves are slopping around in the guides.A haynes book will give you the tolerances and there not a bad job if your carefull.

I had good guides new stem seals and rings when i did my rebuild and can honestly say it uses next to no oil at all.

sandyc

The mileage is about 150k however the car has had a replacement engine so Im not too sure of its history on that front.
There is no wear ridge at the top of the bores and the plugs havent fouled up. However I think I will splash out on rings, sump gasket and big end bolts just to be on the safe side.
Im going to rebuild the head tomorrow and I'll probably source what I need too.

sandyc

SD where can I locate a set then? I'll need a sump gasket and big end bolts too.

JohnnyN

I would go along with Burts advice just for good measure too. Check out the valve guides and replace the stem seals. Going back many many years ago I had a MK1 Astra 1.6SR that smoked on startup and under acceleration. New stems seals cured that problem.

Had you checked compression before the strip?

vocky

there is no sump gasket, just gasket sealant.

also the conrod bolts can be reused :thumbup:

sandyc

I didnt actually check the compressions. I pulled the plugs out and they didnt seem to be fouled with oil so I carried on stripping the head off with the intention of doing the stem seals only. Now Ive found the movement in the pistons Im thinking again.

vocky

I find that the oil scraper rings get sludged up and don't move freely 🙁

Martyfart2013

Wished I did my rings when I had head off