Technical Excessive oil consumption after rebuild

[Kunal]

My palio's engine has been rebuilt recently (1242cc 8v). However, it is burning alot of oil (about 1 litre every 100km). There is no noticeable smoke coming out of the exhaust, but the 3rd and 4th spark plugs are fouled. I have taken the head of but am unable to tell whether the valve seals or the oil control rings are defective/damaged. There is a lot of oil in the 3rd and 4th cylinders. From the intake ports, the valve stems look a little more oily than the other ones, but that could be gummy deposits from the fuel. How do I check whether the oil seals or the oil rings are the problem. I am worried that the oil rings may have broken. I did a compression test before taking the head off and all 4 cylinders were approximately 190 psi. The car has done about 650km since the rebuild.

 

[Peter Pick-Up]

Who did the rebuild, and what was done?
(While the head is of, it's easy to put new valve seals on anyway...)

 

[Kunal]

The engine had overheated due to the front core plug coming off (timing belt side). There was damage to the 4th piston and the bearings were making a noise, hence the complete rebuild.
The bearings, sleeves and head work were done at a machine shop.

I had the oil seals replaced. The oil burning was still there for some time, then it stopped. However, the 3rd and 4th spark plugs still had a little more carbon on them than the others.
Yesterday when I checked the plugs, the third one had oil all over it and was black but not as much as before. The head most probably has to be taken off again. The problem could be bad valve seals but I still have doubts on the rings.
Is there any way to check if the oil rings are ok without removing the pistons?
If I do have to remove the pistons just to check the oil rings, will it harm the seating of the compression rings in any way?
Please advice.

 

[Peter Pick-Up]

Compression test.

 

[kingdavid]

The pistons obviously have come out to check the rings, easy if the head is off. Just do not mix up the parts, Everything must go back where it came out. Check the oil rings to make sure they are linked correctly, this can be tricky lining up the markers. Someone else can give you the technique.

 

[Kunal]

I have done a compression test. Each cylinder is about 190 psi.
I don't think the compression test will show the condition of the oil rings. Will it?

 

[Kunal]

The pistons obviously have come out to check the rings, easy if the head is off. Just do not mix up the parts, Everything must go back where it came out. Check the oil rings to make sure they are linked correctly, this can be tricky lining up the markers. Someone else can give you the technique.

What markers are you refering to? (the end gaps?)
Also, will removing and reinserting the pistons affect the seating of compression rings or reduce compression?

 

[Peter Pick-Up]

Right, I was thinking about the compression rings...