Air Cleaner Oil, 1939 P8

[Bill E Bob]

Thanks to both of you - I appreciate your information & help - it's always great to learn how things work & other's experiences

BIll

[Fr Mike]

  I, too, have a heavy duty (oil bath type) air cleaner on my '36 P2.  It seems to me that a low-priced oil thick enough so it won't slosh around should work just fine. In fact,I have some left-over straight, non-detergent 30w and 40w engine oil left over after rebuilding the engine that I have been using with very satisfactory results.

[plym_46]

You can use any oil you use in the crank case.  the oils job is different than it appears.  The air does not actually pass through the oil.  The oil acts as a trap to hold particles that are forced out of the incoming air stream.

The design of the air cleaner forces the air into a sharp 180 degree turn from straight down to straight up.  As the air makes that turn the particles that are travelling with it ,being heavier than the air .and can not make the trun, the larger ones fall into the oil reservoir where they are trapped.  Any oil that gets atomized gets sucked upward to the material in the mesh at the top of the filter, this oil and mesh traps the smaller particles.

It is important not to overfill the reservoir, not so much the vicosity of the oil.  Some might say that thinner oil will more readily slosh around but I would thik that would be a minimal concern.

[Bill E Bob]

I want to replace the oil in the heavy duty air cleaner on my 39.  The shop manual says to use SAE 50 oil, & I have found a Kendall SAE 50 GT-1 high performance with liquid titanium oil. I would appreciate it if anyone could advise if this is OK to use, or maybe suggest a better alternative.

Thanks BIll