space present within cover 23 a first end 27 of conduit 26 is sealingly engaged with cover 23 to place the air space within cover 23 in fluid flow communication with an air space in a sensing chamber in apparatus 4 to provide an equal air pressure in each air space 22 and the air space in apparatus 4 in air space 22 a veritable oil laden hurricane is present during operation of the engine violent air currents caused by rapidly moving components and blowby gases impel oil droplets and spray throughout air space 22 and violently agitate and distort the surface of oil pool 20 it is to be understood that any air space or air containing location within the engine which is relatively calm and substantially oil free compared to air space 22 will aid the function of the vent means the air space within cover 23 is particularly good because the fluid passages which place it in fluid flow communication with air space 22 dampen air pressure surges attempting to travel from space 22 to the space within cover 23 also though there are oil sprays present within cover 23 and some air turbulence due to rocker arm movement this space is relatively calm and substantially oil free compared to space 22 fig2 shows apparatus 4 and crankcase 18 as shown in fig1 in enlarged detail as in fig1 the pool of oil 20 fills crankcase 18 to a desired level 21 and an air space 22 is present above the oil pool air carrying conduit.