Quote:
Originally Posted by JSeery
I see a lot of post of the vacuum side of PCV systems but not much on the air inlet side. If a proper filtered air inlet is not present you are going to be drawing dirty air into the crankcase.
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I thought about this and agree but I don't know if it will make much difference. The engine is a 21 stud 1936. It had the oil pan road draft tube, brass screened oil stand scoop and the labrynthe rear crank seal. Unfiltered air could enter from potentially 3 places. The clutch housing would seem to me to be the source of the worst air because of the clutch dust and the rotating assembly potentially acting like a fan and pressurizing the clutch dust into the crankcase through the rear seal.
When I disassembled the engine it was full of sludge but that sludge did not show evidence of particulates upon visual inspection. This suggests that the crankcase does not ingest air from the clutch housing. Also, air movement inside the crankcase is not ingesting much from outside through the oil stand scoop or it would not have been full of sludge. On my 21 stud post-mod the airflow will not cross the entire engine from top to bottom as before because the pan draft tube is now plugged. The airflow is now from oil stand to front of the manifold.
Given that at a stop sign oil vapor exits the oil stand, I have to think there just isn't that much air entering the crankcase through the oil stand with the engine running. What is exiting is probably the result of the heat acting like a flue, air flow has to reverse through the draw of the road draft tube every time the car moves. In either of the two, road draft or pcv, I just don't think there is a great volume of air being moved through the engine to carry significant amounts of dirt.
The next guy to tear the engine down will get the results of my experiment.