Soup up trick.

[Signman]

ED
Back in the mid 90s when helping my friend on his alcohol dragster remember him saying then that in the past S/SS racers would come around looking for used oil from A-Fuel cars because of all the nitro that would be mixed in it.
Guess back then some used a PCV valve but considering ring technology and honing was not as good as today a little oil / nitro mix sucked by the rings could make some power.