Pistons & rings

[DavidSwedem]

I am rebuilding a 1971 2.2 T engine.

The pistons and cylinder clearence is 1.6 mm on all cylinders. The ware limit is 1.5, do I really need to buy new cylinders and pistons...it will cost me an arm and a leg. If I need to do this what are the best value for money options?

The piston rings are all within the clearence wear limit (1mm) except the oil seal ring this is over 1mm on all cylinders. Is there some reason why this ring shoild ware more than the others?

Finaly can anyone tell me about the piston, the dimensins are not stamped on the top also the cylinders are not marked with size?

Thanks

[gled49]

My experience on ring to ring grove clearances is the max spec is the wear limit, not the wear limit.

[PeteKz]

I'm not a 2.0/2.2 guru, but your numbers look way off to me. Are you sure that the wear limit is "1.5mm"? In my experience, that should be more like 0.15mm. And a ring end gap of 1mm sounds like too much also. It should be half that or less. Ring to piston groove clearances are usually around 0.05-0.10mm.

How are you measuring? Are you using inside and outside micrometers (calibrated to each other), and are you measuring at the correct locations on the skirts of the pistons? Do the pistons and cylinders have wear marks? Post pictures of those too.

If the correctly measured clearance really is 0.16mm, and a new set exceeds your current budget, I would consider reusing them. Other questions for your decision: How old are you and how many miles do you think you will put on this engine? If you are young and think you will go more than 100,000miles/160,000Km, then consider buying new pistons and cylinders. If not, then it will be for the next owner to deal with!

[Dpmulvan]

Originally Posted by DavidSwedem

I am rebuilding a 1971 2.2 T engine.

The pistons and cylinder clearence is 1.6 mm on all cylinders. The ware limit is 1.5, do I really need to buy new cylinders and pistons...it will cost me an arm and a leg. If I need to do this what are the best value for money options?

The piston rings are all within the clearence wear limit (1mm) except the oil seal ring this is over 1mm on all cylinders. Is there some reason why this ring shoild ware more than the others?

Finaly can anyone tell me about the piston, the dimensins are not stamped on the top also the cylinders are not marked with size?

Thanks

Not sure about a 2.2 but minimum ring gap ( tightest stock) for a normally aspirated engine is around .016 which would be .4064 in millimeters. Check your numbers.

[brighton911]

David, your numbers are confusing. May I suggest you take the pistons & cylinders to an engine builder and have them measure them.

[targa72e]

These are the specs for 2.4 engines (same bore size as 2.2). Has ring side gap , Piston to cylinder clearance, ovality and ring end gap and wear limits for all. Piston diameter is measured at dimension H.






john

[stownsen914]

I'm wondering if he meant thousandths of an inch, not mm. Or just missing some decimal places.

OP - can you clarify what is being measured and what the units of measurement are being used?

[DavidSwedem]

Sorry I made a typo:
I mean 0.15mm I believe that this is the max clearence allowed between piston and inside of cylinder. I have 0.16mm, do I need new pistons & cylinders or will I get away with it?

Regarding rings: I believe 1mm is the max gap allowed when the ring is placed into the cylinder. All my rings are within this but not the scraper which is over, why should this ring have so much ware?