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Graham Specifications



Make & Type                                   Graham-centrifugal

Drive                                                   Twin V-belt

Ratio, rotor to engine                    5.75 to one

Ratio of gearing                               4.8 to one

Rotor material                                 Aluminum

Rotor diameter                                 7 ½ inches

Type bearing                                     Special “cone” worm

Number of bearings                       Five

Bearing Types:

  Worm Shaft                                     Bronze-babbitt

  Rotor Shaft                                       Bronze-babbitt

              Rotor Shaft Pilot                             Lead-bronze

Rotor cover type                               Water jacketed


            Make                                                     Graham

            Type & number of cylinders          L-head, 6cylinders

            Bore & Stroke                                      3 ¼” X 4 3/8”

            Cubic inch displacement                 217.8”

            Brake horsepower @ RPM             93 @ 3800 non-supercharged

                                                                              120 @ 4000 supercharged

            Horsepower rating (AMA)               25.35

            Maximum Torque                               170 Ft-Lb

            Compression at cranking speed     125 lbs non-supercharged

                                                                               130 lbs supercharged

            Firing Order                                           1-5-3-6-2-4

            Engine Mounts                                     3 point rubber

Engine Speeds (Rev./ mile) Standard axle (4.27)

          Overdrive                                               2255 non-supercharged

                                                                               2224 supercharged

            High gear                                               3181

            Second gear                                          4930 non-supercharged

                                                                              4863 supercharged

            Low gear                                                8175 non-supercharged

                                                                              8064 supercharged

            Reverse gear                                         11069 non-supercharged

                                                                               10920 supercharged

Engines Speed Optional Axel (4.55)

            Overdrive                                               2402 non-supercharged

                                                                              2370 supercharged

            High gear                                               3389 non-supercharged

                                                                               3344 supercharged

            Second gear                                           5252 non-supercharged

                                                                               5183 supercharged

            Low gear                                                 8709 non-supercharged

                                                                               8594 supercharged

            Reverse gear                                         11793 non-supercharged

                                                                               11637 supercharged








Cylinder Head

 Material                                               Iron

Type                                                      High Compression

Compression ratio standard              6.65 to one

No. of optional heads                          2

Ratio of optional head                        7.00 to one

Ratio of special optional head           7.25 to one


Intake valve material                      Chrome nickel steel

Intake valve seat angle                     30 degrees

Intake valve head diameter              1 33/64”

Exhaust valve    material                   X.B. steel non-supercharged

                                                                  X.C.R. steel supercharged

Exhaust valve angle                            45 degrees

Exhaust valve head diameter            1 21/64”


Type                                                       Integral with cylinders

Material                                                Copper-Chrome Iron

Water jacket type                               Full length of cylinders

Cylinder bore finish                            Honed

Crankcase oil capacity                        5 Quarts

Crankcase ventilation                         Cross flow

Crankcase air cleaner                         Wire mesh


Material                                               Forged steel

Features                                              Integral counter-weights

Number main bearings                     Four

Main bearing diameter                     2 3/8”

Bearing Journal Lengths:

 Front                                                    1 9/32”

 Front center                                      1 ½”

 Rear center                                        1 ½”

 Rear                                                       1 47/64”

Bearing type                                       Interchangeable

Bearing material                               Steel shell, Cadmium silver

Connecting Rods

Material                                               Forged steel

Length                                                  7”

Bearing type                                     Interchangeable

Bearing material                             Steel shell, Cadmium silver

Bearing diameter and length         2 7/16” X 1 3/16”


Make & Model                                 Carter WA-1

Type                                                    Down draft

Outlet                                                  Single

Size                                                        1 3/8”

Adjustments                                     Idle only


Fuel System

Gas tank capacity                                      17 Gallons, US

Fuel feed                                                     Mechanical pump

Pump type                                                  Diaphragm

Fuel filter                                                     Integral with pump

Air cleaner type                                          Oiled copper mesh

Fuel temperature regulation                    Thermostat non-supercharged

                                                                      Automatic supercharged

Fuel heating medium                                 Exhaust heat non-supercharged

                                                                      Water supercharged

Choke control                                              Automatic


Engine lubrication                                      Pressure

Normal Oil pressure                                  45 Lbs.

Pressure oiling to                                       Entire engine, internal

Crankcase capacity                                    5 quarts, pus one with filter

Oil pump type                                            Submerged gear

Oil pump drive                                          Geared to camshaft

Chassis lubrication                                            Pressure gun

Number & type fittings                          14, Ball end

Pistons & Rings

Piston make & material                         Bohn-aluminum

Piston type                                              Auto-thermic, steel struts

Piston finish                                             Bearing metal plated

Compression ring width                         3/32” two used

Oil control ring width                             5/32” two used

Piston pin diameter                                13/16”


Drive                                                        Link belt

Chain width & length                             1” X 23”

Chain pitch                                              ½”

Bearings, number & material               4, Bronze

Cooling System

Type circulating                                     Pump

Pump type                                              Centrifugal-packless

Bearing type                                           Double row ball bearing

Bearing lubrication                                 Not required

Pump circulating capacity                     45 Gal. Per minute

Radiator type                                          Cellular

Cooling system capacity                        14 Quarts

Water temperature control                  Thermostat

Fan diameter & blade number             16”, four