can an engine quit using oil

[scrappyk5]

i have a vette that sat around for awhile. well when i bought it i fixed a few things but noticed it was using oil. about a quart every 250 miles. well i have put about 6000 miles on it and i have been checking to add oil and is using less and less. i say about a half quart in about 400 miles. so i assume either valve seals have sealed up or rings have.
does this sound right or possible ?

 

[k20]

if the motor was recently rebuilt, it could have been that the rings werent seated and were using oil.

 

[diesel4me]

Yup!

I have had similar experiences with older cars--especially ones we "woke up" after a long nap--it seemed the longer we drove it,the lower the oil consumption became,until it leveled off...its probably due to the rings sticking or being sludged up,and running it frees them up--also if the cylinders got a bit rusty,they would get scraped clean after awhile,and carbon would fill in the scratches after many miles..and the smoke decreased or stopped--thats how that "restore" stuff works--(I dont reccomend that stuff at all however--I seen it ruin more motors than it helped--might be ok for a motor thats junk otherwise,and you dont care if it finishes it off)..

We sold a few engines at the junkyard that smoked so bad we sold them cheap as rebuildable cores--more than one guy simply soaked them in kerosene for a week and drained them out,ran them with 5w-30 oil at first,( or oil with Marvel Mystery Oil),changed it after a few hours of running,and put the usual 10w-40 or 20w-50 in them,and they hardly smoked at all--a few blew up too!...