Mercedes-Benz Grand-Prix racing car W 154, 1938

Engine type:
M 154/8
Inlet valves:
2 inclined overhead valves per cylinder, actuated via finger followers
Ignition sequence:
1-8-5-10-3-7-6-11-2-9-4-12
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
Ignition adjustment:
Automatically
Combustion principle:
Four-stroke Otto (with 2 superchargers)
Crankshaft:
7-bearing (roller bearings)
Bore x Stroke:
67 x 70 mm
Fuel system:
1 two-barrel suction carb. with add. slide-valve carburetor / 2 Roots superchargers
Total displacement:
2963 cc
Spark plugs:
1 per cylinder, Bosch 450 G 4
Fuel supply:
Graetzin ZE 450 Mul fuel pump
Compression ratio:
7.5
Fuel tank capacity:
233 l
Maximum / output / rated output:
468 hp at 7800 /min; 454 hp at 7500 /min *
Fuel consumption:
app.180 l
Rated torque:
50 mkg at 5000 /min
Cooling:
Glycol/water circulation cooling
Maximum revolutions:
8000 /min
Lubrication:
Dry sump lubrication via 9 suction and pressure pumps
Cylinders:
2 steel blocks per cylinder bank with welded-on cooling-water jackets
Oil consumption:
2.7 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:
2 Bosch magnetos

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:
6.50 x 19 (over 270 km/h) else 5.50 x 19
Frame design:
Oval-tube frame with 4 cross members
Rear tires:
7.00 x 22 (over 270 km/h) else 7.00 x 19
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:
5-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
Gear ratios:
Depending on the race
Final drive ratio:
Depending on the race
Maximum speed:
330 km/h

Wheelbase:
2730 mm
Front track:
1475 mm
Rear track:
1412 mm
Length:
4250 mm
Width:
1750 mm
Height:
1010 mm
Vehicle weight:
981 kg**
Comments:
Design: O. Wagner and H. Heess under the direction of Dir. Max Sailer *Standard Oil racing fuel WW: 88.0 % methyl alcohol 8.8 % aceton 4.4 % nitrobenzene 0.8 % sulphuric ether **Weight when ready to be weighed according to formula regulations: 981 kg, minus: 17 kg cooling water 9 kg engine oil 6 kg fender suspension amounts to: 949 kg not including driver Empty weight not including tires: 850 kg
Engine weight:
253 kg
Seats:
1