bad rings?

[95nismo240]

i have a 95 nissan 240sx auto. i just had a used 96 engine swapped into it. i had no problems with it, except that i heard that the cat was making noise. i decided to just take the cat out and having the o2 sensor welded back on. when i started the car up and drove it for a little while i noticed a puff of bluish greyish smoke come out the tail pipe. i noticed that the smoke gets alot worse when the car is at normal temperature. i drove it like this for about a week or two cause i had to go to work. i checked the oil after and i had to add 3 quarts!! im thinking the rings are bad. i did a compression test when i put the engine in and all cylinders where around the same.

[midnightsliding]

what was your compression across .

[240sx2nr]

was the compression low? could be a number of things

[95nismo240]

i dont remember if it was 120 or around 160. but they were all around the same number.

[hachibroku]

The Compression max is 179 and the min is 151 with a tolerance of 14psi.