Intermittent crankcase pressure issues

Deceus said

This has nothing to do with what I said. Yeah if the exhaust valves are shut when they need to be you are in fact correct. Please read where I had oiling issues and bent some pushrods last year. Logic would lead me to believe I probably messed up my valve guides as well to some degree.

Plenty of people run without a hose hooked up to the air cleaner. I have a big breather and pcv. Sure I could find a way to vent all this pressure but this pressure is telling me something is wrong.

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I read that part, if anything happened it could have bent some valves slightly which would have made it run not-so-great (bad valve sealing). However just by how small the "gap" is between the valve stem and guide and how briefly there's actually any pressure there (which is actually usually negative because the exhaust gases are moving at very high speed through the port) I don't see how it's possible to get pressure up past the guides into the crankcase that way.

When my Duster was still running with the 360 I had in it I initially had a PCV valve on one side and an open breather on the other. I found that under hard running the breather would push up like it was going to pop out the valve cover and would leak oil. The first issue is that most of those breathers you buy from the parts store are super restrictive; I pulled about half the "filter" material (some kind of foam like for 2-stroke engine air cleaners) until I could blow on it and actually have airflow. Then I bought a breather with the hose fitting on it (and again had to remove about half the filter media) but since I had an open-element air cleaner I just routed the hose to right in front of the air filter.

What some of us are trying to get at is: your engine may not actually have too much blowby it just doesn't have a good way to vent the pressure. Now that the engine is out of the car you can't monitor the actual amount of blowby being pumped out by the engine so now all you can really do is play Detective and tear down the engine looking for clues.