Mercedes-Benz W 25 record car, 1934

Engine type:
M 25 B
Inlet valves:
2 inclined overhead valves per cylinder, actuated via finger followers
Ignition sequence:
1-6-2-5-8-3-7-4
No. of cylinders / arrangement:
8 / in line
Outlet valves:
2 inclined overhead valves per cylinder, actuated via finger followers
Configuration:
Front, longitudinal; vertical
Valve operation:
2 overhead camshafts, gear drive
Ignition adjustment:
Automatically
Combustion principle:
Four-stroke Otto (with supercharger)
Crankshaft:
5-bearing (roller bearings)
Bore x Stroke:
82 x 94.5 mm
Fuel system:
2 Pressurized carburetors / Roots supercharger
Total displacement:
3360 cc
Spark plugs:
1 per cylinder, Bosch M 450 G 1
Fuel supply:
Junkers three-piston pressure pump
Compression ratio:
7.5
Fuel tank capacity:
215 l
Maximum / output / rated output:
430 hp at 5800 /min
Fuel consumption:
app.100 l
Cooling:
Water circulation cooling via feed pump, no fan fitted
Maximum revolutions:
5800 /min
Lubrication:
Dry sump lubrication via lubricating pump
Cylinders:
2 steel blocks (of 4 cylinders each) with welded-on cooling-water jackets
Oil consumption:
2.3-6.2 l
Cylinder head:
Not removable, welded together with cylinders
Starter:
Inertia starter
Generator:
Not fitted
Battery:
Not fitted
Ignition:
High-voltage magneto ignition
Ignition system:
Bosch magneto

Hand brake:
Acting mechanically on rear wheels (cable controlled)
Foot brake:
Acting on front- and rear wheels
Steering:
Worm-and-nut steering
Wheels:
Wire-spoke wheels, center mounting
Front tires:
5.25 x 17
Frame design:
U-section pressed-steel frame with bores for weight reduction
Rear tires:
5.25 x 19
Front wheel suspension:
Double wishbone, coil springs (horizontally mounted in axle tube), friction shock absorbers
Drivetrain:
By cardan shaft to transaxle and rear wheels
Rear wheel suspension:
Swing axle with transversal cantilever springs, friction shock absorbers
Brake system:
Hydraulically actuated
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 in unit with differential gear, mounted below rear axle
Shifting:
Gate shift with locking system
Clutch:
Dry single-disc clutch
Transmission type:
Change-speed gear
Maximum speed:
318 km/h

Wheelbase:
2725 mm
Front track:
1473 mm
Rear track:
1412 mm
Length:
4040 mm
Width:
1770 mm
Height:
1160 mm
Vehicle weight:
847 kg*
Comments:
* Car weight not including tires, oil and water as per Formula: 750 kg
Engine weight:
211 kg
Seats:
1