Cummins Engines

Cummins Marine - 420 Diamond Edition

High Output Rating U.S. Std Metric
Crankshaft Power 420 BHP 131 kW
Rated Speed 2600 rpm 2600 rpm
Fuel Consumption 23.3 gal/hr. 88.2 L/hr.
Bore x Stroke 4.49" x 5.32" 114 x 135 mm
Piston Displacement 504.5 cu. in. 8.3 L
Compression Ratio 15.5:1 15.5:1
Dry Weight* 2239 lb. 1016 kg
Metric HP (mhp) 426 426
Cummins Marine 420
Four Stroke Cycle, Turbocharged, Aftercooled,
Direct Injection, In-Line, 6 Cylinder Diesel Engine

Design Features:

Replaceable, precision type aluminum steel backed. Seven main bearings 3.86 in. (98 mm) diameter. Connecting rod bearings 2.99 in. (76 mm) diameter.

Hardened cast iron for increased wear resistance and long life. Seven replaceable type precision bushings 2.36 in. (60 mm) diameter.

Connecting Rods:
Drop forged I-beam section, 8.50 in. (216 mm) center-to-center length. Rod is tapered on piston pin end to reduce unit pressures.

Eight counterweight fully balanced high tensile strength steel forging with induction hardened fillets and journals.

Cylinder Block:
Alloy cast iron with removable wet liners.

Cylinder Head:
One piece cross flow cylinder head for short length and maximum structural stiffness of block/head assembly. Contains replaceable valve guides and seat inserts.

Cylinder Liners:
Mid-stop replaceable wet liners feature a new liner clamping method which seals at the middle of the liner with a press fit at the top. This design eliminates the need for packing rings and crevice seals.

Raw Water Aftercooler:
Large capacity aftercooler results in cooler, denser air for more efficient combustion and reduces internal stress for longer life.

Two Valves Per Cylinder:
With single valve springs, for fewer parts.

Water Cooled Exhaust Manifold and Water Cooled Turbo Charger:
Configures for rear-out exhaust for lower profile.


Available Equipment

Accessory Drive System: 1 and 2-groove front crankshaft pulley.
Air Intake System: Mounted light duty air cleaner. Remote mounted heavy duty air cleaner.
Cooling System: Mounted heat exchanger, raw water pump, expansion tank and marine gear oil cooler.
Electrical System: 12 or 24 volt starter, alternator, and fuel shut off valve. Alternator belt guard. Instrument panel not mounted. Fully wired engine.
Flywheel Housing and Flywheel: SAE No. 3 housing. Flywheel for 11.5 in., or 10 in., over center clutch. SAE No. 2 housing. Flywheel for 11.5 in., over center clutch.
Fuel System: Fuel water separator not mounted.
Lubrication System: Shallow sump cast aluminum oil pan. Port or starboard dipstick location.
Marine Agency Certification: Available from LR,BV,DNV,ABS.
Mounting System: 4 point mount on 26 in., (660 mm) or 28in. (711 mm) center. Various gear brackets. Vibration isolators.