Cadillac Model D 1905

Theprice of the Model D was $2800. Calendar year sales and production was 156 units. Model year sales were also 156 units.

The Model D was introduced on January, 1905.

Innovations included:

• Three speed planetary transmission.
• Governed throttle.
• Variable lift inlet valve gear on multi-cylinder engine.

The four-cylinder Model D had a five passenger touring body with side entrance tonneau doors and a wood body. Aluminum skins were available at extra cost. It also featured running boards and an aluminum dash. It also had a carrying lubricator and running fuel tank with gravity feed to the mixer. The storage fuel tank was located at the rear of the chassis. Fuel transfer was made to the running tank by exhaust pressure.

The chassis emphasized strength and durability with a pressed steel frame. It had two half-elliptic springs in front and a platform spring in the rear. It featured right hand steering with controls to right. The brake lever operated the service brakes on the rear drums. A foot pedal operated the emergency brake on drive shaft. The application of either brake system disengaged the flywheel clutch through an interlock. The engine and transmission were mounted in a tubular subframe. It also had a patented double syphon muffling system.

The driveline had a three-speed planetary transmission (3:1, 2:1, 1:1). All speeds were activated progressively with a single lever. There were twin clutch discs in the flywheel; a disc clutch and three bands on the transmission; and an emergency brake drum behind transmission. Instead of being chain driven, it had a shaft drive with two U-joints linked to a bevel gear. The live rear axle had a spur gear differential.

The four cylinder vertical in-line L-head engine had counterclockwise cranking. Individual cylinders had copper water jackets and the heads were detachable with factory equipment. The lower section of the two-piece crankcase held the carrying mains and a patented sloping-trough splash lube system which insures lubrication to each cylinder regardless of grade. The horizontal commutator shaft projected forward into cavity in radiator. The commutator was serviced from the front of vehicle. The number one cylinder was over the front axle with a stretched out accessory section on the front of the engine. The radiator extended forward of the front tires. The hood is one quarter the length of the car.

Engine throttle control was a complicated variation of the one cylinder throttling arrangement. The L-head valves were operated by in line push rods and roller tappets riding on extra wide cams on a spring loaded, sliding camshaft. Exhaust cams were of constant cross section but inlet cams were cone shaped to produce varying lift and timing as the camshaft moved along its axis. The axial motion of the camshaft against its return spring was by a hydraulic piston which received pressure from an engine driven pump. The throttle control on the steering column operated a bypass valve in the hydraulic loop. The position of this valve regulated the percentage of system pressure acting on the camshaft piston, thus the nominal axial position of the camshaft. The governor action was automatic due to interaction between the engine driven pump speed, hydraulic pressure, and cam position (overspeed increased the pressure and drove the cam back to a lower speed position). As on the one cylinder engines, the inlet valve opening automatically determined the amount of fuel supplied by the mixer. The mixer was identical to the one cylinder mixer except for the addition of an auxiliary air intake valve.

In addition to patents pertaining to one cylinder cars, Alanson Brush also held patents on the splash lubrication system and the muffler system used on Model D. Although not patented, counterclockwise cranking was a Brush “trademark.”