Strange oil consumption

[Truckedup]

My 50 Chevy truck has a recently rebuilt 261 inline 6 engine.This is a vintage performance engine with hotter cam,forged high compression pistons etc.The valve guides fitted with modern type oil seals.And not the first one like this I've built.It's got about 1200 miles on it now and I have been checking the oil regular after changing the oil several times.Using Brad Penn 20/50 for the somewhat sloppy designed in clearances used on vintage performance engines.In the 600 miles the oil went down barely at all,no problem.Then in maybe 85 miles it goes down 3/4 of a quart!!! What the [censored]? No oil smoke,no leaks,no PCV valve on this engine.Pulled the spark plugs,all look clean off white with no signs of oil deposits or carbon.I check the oil the same way every time on a level surface.Obviously oil level can vary slightly depending on oil temperature etc.The oil pressure is fine for this engine.
last night I top off the oil and take a 100 mile hiway run.Checking the oil cold,the same way I checked it before the trip,zero oil consumption.
Any of you has weird stuff like this happen?

 

[CourierDriver]

My body works the same way, I was 4 yrs old in 1950 and Im a quart low most of the time. Hey, engines get old, even rebuilt ones, u know, hip replacements, knee replacements, eye surgery, so why would an old block with new parts be any different, its a thought. Hey, take the old ride for a 80 mph run and see if she holds up, no guts, no glory, now where are my teeth. PS, sounds like ur truck is fine, let it break in some more.

 

[Truckedup]

Well,I'm three years older than the truck and my oil consumption is one fish oil tablet per day

 

[Gene K]

Ring Gaps lined up for a bit?

 

[Truckedup]

Originally Posted By: Gene K
Ring Gaps lined up for a bit?
Anything is possible.Been driving all over and driving hard and the oil level hasn't dropped any at all.

 

[Gokhan]

Sometimes oil dipsticks are not linear. They might indicate slow consumption when the oil is full and then fast consumption when there is less oil, even though the actual consumption rate doesn't change. Try topping off the oil and if the problem goes away, this would then be just an artifact of having a nonlinear dipstick.

 

[mechtech2]

Recent rebuild?
Fuhget about it.
Keep an eye on things, though.

 

[dave1251]

Interesting indeed. I would just chalk this up to the fresh rebuild just keep an eye on the oil level and check before each trip.