The pump is of the balanced-rotor type and has but one stuffing
box, packed with self-lubricating metallic packing. The rotor is of navy bronze,
non-corroding and is balanced. Water is taken in on both sides simultaneously, thus
excluding all side thrust. The pump shaft is of stainless steel, also non-corroding, and
is driven by a splined fitting on the engine cross-shaft coupling. Unusual
accessibility is gained by this mounting. No grease cups are used on the pump, thus
eliminating the possibility of grease entering and clogging the radiator or cylinder
jackets, another instance of designing for dependability.
Force feed and splash lubrication are combined in a unique manner. Circulation of
the oil is produced by a gear pump located at the bottom of the crankcase oil sump, and
driven, as already mentioned, from the camshaft. This pump raises the oil in
abundant quantity and under moderate pressure from the crankcase sump to an auxiliary
reservoir at the upper left front of the cylinder block and cast integrally with it. With
only a thin wall separating the reservoir from the water jackets, the oil is quickly
warmed on starting the engine, and is maintained under all operating conditions at a
practically constant temperature by the cooling water in the cylinder jackets. This
eliminates the dangers of sluggish circulation of chilled oil as well as the disastrous
effects arising from overheated oil that has lost its lubricating value.
From the auxiliary reservoir oil is fed to all three main bearings
and to the four splash troughs beneath the connecting rods. Scoops on the ends of
the rods, dipping into the oil at each revolution, convey an ample amount to the crankpins
and throw the balance in the form of a spray over the valve lifters, wristpins and cylinder
walls. Oil in the splash troughs is kept at at constant level by continuous overflow, the
amount of oil fed being always in excess of actual requirements. Surplus oil in the
reservoir is conducted through a large tube to the timing gears, bathing them in a
constant cataract of oil.
The oil is twice screened each time it circulates; first, as it is
sucked into the pump, and then again as it enters the upper reservoir. Both screens
are readily removable for cleaning, the pump screen through a trap at the bottom of the
crankcase, while the other is lifted out by unbolting the reservoir cover-plate.
With the exception of the short oil pipe leading from the reservoir to the timing gears
and the oil gage lead, all oil piping is cast in the crankcase and cylinder block which
insures rigidity and freedom from breakage.