Blow By ??

I had zeigler cat at altoona ia run my 6nz its blow by was like 660 and they told me that number represented air flow by volume.
If I remember correctly cubic inch per hour.

 

what would cause massive engine blowby on a 110,000. mile cummins isc260? blowing engine oil out the blowby tube.

 

Cylinder scoring from overheated piston.

 

Yeah i have tried on an ISX motor with a homemade manometer. I was told acceptable blow by is 1 inch per 100k miles. Any less is great and more is bad. Tried the same test on Mack motors but it just blew the water out of the tube! Not sure if it was that bad of a motor or if it works differently per engine.