TheMODEL S has the same chassis as the 1907 model except the wheelbase on all body styles increased to 2083mm and full running boards replaced the step plates. Single and double rumble seat options were available on the straight line or Victoria styles runabouts. If rumble seat passengers were to be carried regularly, it was recommended that tire size be increased from 30 x 3 to 30 x 3-1/2.
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1907 Cadillac Model S
runabout with rumble seat
I. D. DATA
Serial number location
Serial numbers on plate on rear of body (with engine number.
Engine numbers were stamped two places on crankcase:
Top, right edge of cylinder flange, near water outlet.
Top surface of left, front mounting leg.
Also on plate on rear of body (with serial number).
(Blank spaces on patent plate are for additional patent dates, not engine or serial number.)
Model S engine no.
24075-24350 with K,- M, T (1907), 24351-25832 with T
Straight Line Runabout
Victoria Runabout w/single rumble
St. Line Runabout w/double rumble
Horizontal, with cylinder to rear.
Number of cylinders
Cast iron cylinder, with copper water jacket
Bore & stroke
127mm x 127mm
“Higher than advertised or calculated”
Updraft mixer manufactured by Cadillac
Optional Front/Rear Tread
30 x 3
2 Forward (3:1 and 1:1), Reverse (3:1)
Low (foot pedal), reverse & high (lever to the right)
3.1:1 to 5:1
Mechanical brakes on two wheels; contracting on inboard drums
Wood wheels, 12 spokes
Touring & Roadster Wheel size
On the models M, S & T, different combinations of 9 or 10 tooth driving sprocket with 31, 34, 38, 41, or 45 tooth driven sprocket gave ten possible ratios from 3.1:1 to 5:1.
9 tooth drive sprocket
10 tooth drive sprocket
Lower ratios for runabout to be run on smooth, level roads to higher ratios for loaded Delivery to be run on rough, hilly roads.
Instructions for changing sprockets were available for owners, but the change involved disassembly of the transmission and rear axle — definitely not a “quick-change” set-up.