Re: High Zinc (ZDDP) Engine Oil: My 2 cents
Just for my understanding: I realize the low-volume setup was not the best in regards to filtering the oil but would this old way of filitering still not be loads better that the Kolher's that replaced the Gravely-made engines that had no oil filter?
There is a big difference between the oiling system of Gravely engine and a Kohler engine.
A Kohler engine does not share chassis lubrication, a Gravely engines does. A Kohler engine uses something less than one quart of oil kept in its bottom oil resivor. Kohler uses a 'dasher' on the bottom of the connecting rod to splash oil around in the bottom end and cylinder walls.
A Gravely engine uses five pints of oil. The low volume oil pump system pumps oil from the bottom of the chassis into the crank pin, drive pinion bushing and sun gear in the high/low planetary assembly. Oil that may have picked up some debris during an attachment change, oil that is sucked up through a piece of screen door screen and then pumped right back into the main engine componet, the crankpin. The spinning flywheels spread oil to the rest of the engine internals.
The high volume oil pump system still picks up oil from the bottom of the chassis, but through a much finer pickup screen; it is then pumped into a full-flow oil filter, and then to the crankpin, drive pinion bushing, and sun gear.
But even with the high volume system I have seen abuse. Water in the chassis will rust the pickup screen and allow nasties to enter the system. The oil breather cap was stuffed with aluminum shavings, I have found those shaving inside the high volume pickup screen and into the oil lines.
Faux Pas are my forte