More 1460 DT436 spewing oil questions

History note-this is a new to me auction buy, got for cheap, overhaul really tight machine, even after inspected by IH mehcanic, Mechanic said even if the combine was shot, the engine is worth what the price was. No idea how long it sat prior to the auction, no idea what grade oil was used in it, I put in 15-40 Rotella.
Issue. Started spewing oil out of Crank vent
tube. About 1 gallon in 70 minutes.
Info. on engine
Starts great, other than cold start of really
working hard does not smoke like she is burning
oil.
Replaced vent breather element
Has valve cover vent, not the side of block.
Engine runs great, plenty of power.
Oil pressure>not sure on #'s, will be buying a
mechanical gauge to test, BUT, when first started
on a 65 degree day, it pegs the gauge, and will
stay there when warmed up and running full
throttle. At idle engine at operating temp(hot),
gauge still stays over 1/2 of the range, closer
to 2/3.
From idle to 1/2 throttle i only have little
puffs of smoke. No oil dripping from vent tube,
bring up to fulll rpm and the oil starts flowing
out of vent tube.
Is it possible oil pressure relief valve is
stuck? Is this only caused by engine wear Ie worn
rings, walls? Just seems like to tight and great
running of an engine to have blowby so bad it
pees out engine oil, yet has no other symptoms of
a worn out engine? Can you all give me some
advice? Bad valve guides? Want to cover all the
bases before I bring it to some one for a sleeve
and piston overhaul.

how much blow-by is coming out of the tube,reason I asked being it has the crankcase vented thru the valve cover blow-by may not be the source of the oil,i've ran into oil being sprayed into the opening in the valve cover from the valve train causing the loss of oil,worst one was a 330 ford truck engine fresh rebuild first trip of a 100 miles took nearly 3 quarts of oil, got to checking and found they had left one of the rocker arm bolts loose and it was spraying oil into the pcv baffle ,tightened up the loose bolt cleaned the plugs cleared it right up, don't know if valvetrain set-up will allow oil to be sprayed near the opening or not on your engine,co-worker got a replacement truck, cat engine if I remember correctly that was blowing oil out around the dipstick they tried several different things to stop the leak with no results, operator told him it would eventually quit leaking and only use 2 qts max as he was keeping a close eye on it,so they decided to see how it would lose without getting too low ,it would quit leaking at a little over 2 qts still runs fine today just without the leak running 2 qts low according to the dip stick

Well, actually the pressure out of the blowby vent tube really is not seem to have alot of flow pressure, have seen alot of them that actuallywhere there actually was alot of pressure blowing out.

You might have a oil jet squirting oil in the wrong direction or being deflected into the area of the breather. I know it is kind of hard to see things clearly under that hood of combine but if you took the breather off,(the three bolt ) and run it you could tell if a stream of oil was being shot in that direction. IH changed their oiling system about three times to the lifters. Originally the rocker arm pedestals just had a groove in them that metered oil over to push rod and that oil was to run down push rod to oil lifter. Then they went to drilled orfice in pedestals on only a couple of brackets. Then all pedestals got a jet to spray oil down the push rod to lube tappets. If one of them is spraying wrong (never saw it but who knows) it may be splashing it onto breather. I know I would at least pull breather and if that is not conclusive I would pull valve cover and run engine. I would also measure blow by pressure with a water mamometer and oil pressure with a good gauge. Normal oil pressure would be in 50 psi range. Regulator valve is under that large plug on side of block, kind of behind breather pipe.