Mercedes-Benz W 125 record car, 1938

Engine type:
MD 25 DAB/3
Inlet valves:
2 inclined overhead valves per cylinder, actuated via finger followers
No. of cylinders / arrangement:
12 / 60° V
Outlet valves:
2 inclined overhead valves per cylinder, actuated via finger followers
Configuration:
Front, longitudinal; vertical
Valve operation:
2 overhead camshafts per cylinder bank, gear drive
Combustion principle:
Four-stroke Otto (with 2 superchargers)
Crankshaft:
7-bearing (roller bearings)
Bore x Stroke:
82 x 88 mm
Fuel system:
2 Solex suction carb. with additional slide-valve carburetors / 2 Roots superchargers
Total displacement:
5577 cc
Spark plugs:
1 per cylinder
Compression ratio:
9.17
Maximum / output / rated output:
765 hp at 5800 /min
Rated torque:
100 mkp
Cooling:
Water circulation cooling/ ice cooling
Lubrication:
Dry sump lubrication
Cylinders:
2 steel blocks per cylinder bank with welded-on cooling-water jackets
Cylinder head:
Not removable, welded together with cylinders
Starter:
Not fitted
Generator:
Not fitted
Battery:
Not fitted
Ignition:
High-voltage magneto ignition

Hand brake:
Not fitted
Foot brake:
Acting on front- and rear wheels
Steering:
Worm-and-nut steering
Wheels:
Wire-spoke wheels, center mounting
Front tires:
6.25 x 22
Frame design:
Oval-tube frame with 4 cross members
Rear tires:
7.00 x 24
Front wheel suspension:
Double wishbone, coil springs, hydraulic shock absorbers
Drivetrain:
By cardan shaft to transaxle and rear wheels
Rear wheel suspension:
De Dion axle, longitudinal torsion-bar springs, hydraulic shock absorbers
Brake system:
Hydraulically actuated dual-circuit brake system
Front brakes:
Inside shoe brakes with finned light-alloy drums, 400 mm diameter
Rear brakes:
Inside shoe brakes with finned light-alloy drums, 400 mm diameter

Transmission:
4-speed manual transmission with differential gear, transversally mounted below rear axle
Shifting:
Gate shift with locking system
Clutch:
Dry single-disc clutch
Transmission type:
Change-speed gear
Maximum speed:
433 km/h