Engine Overview
The 4B Cummins Engine is the popular 3.9-Liter engine used in step van applications including bread, snack, uniform, and other commercial delivery vehicles from Oshkosh to Freightliners. This 4B Cummins engine is also used in various industrial and construction applications. The 4B Cummins Engine are available in 2 different configurations listed below.
NPD utilizes torque plating methods for boring and honing to ensure block straightness, which reduces break-in time and crankcase pressure. In addition, NPD uses OEM or equivalent pistons, rings, bearings, valves and gaskets, making sure that this engine will stand the test of time.
Dynomometer Testing
All of NPD’s Complete Drop-In engines are 100% dyno tested
prior to shipment. Computer controls ensure that each
engine dyno test is conducted under standard, repeatable settings. Every engine is run through a warm up cycle; three separate cruise segments simulating light, medium and heavy throttle conditions; maximum torque and horsepower tests; both high and low idle tests; and a black light leak detection test with dyed oil, coolant and fuel.
100% of pistons, rings, bearings, bushings, gaskets and seals. Matched OEM requirements for piston type depending upon HP and application. All heads get new valves and are vacuum tested to ensure the quali-ty of the valve job. All heads are pressure tested and upgraded to the latest style valve seal. Cylinder head seats replaced 100% new. 100% ground of camshafts’ lobes. All connecting rods are de-magnetized. Core plugs are 100% stainless steel to avoid corrosion. Blocks, heads and crankshafts are 100% magnaflux tested to avoid cracked components. Connecting rods have new bushings installed and both large and small end are remachined to OEM specifications. Crankshaft is checked for size, reground, if necessary, and micro-polished to OEM specifications.
Cummins 4B Engine Configurations
Bare Long block
New cylinder head “untimed”, crank, block & all internals new. Balance gasket set included.
Complete long block
New “Timed” Cylinder Head with camshaft, cam followers and timing gears, water pump, oil pump, oil cooler, front cover and rear cover.
Drop-In engine assembly
This engine will generally include the block, heads, valve covers, oil pump and pan, timing cover, turbo, rear cover, fuel injection pump with injectors, intake manifold, water pump, exhaust manifolds, and oil cooler. (Some of these components may not be included with particular engines or applications based on engine type.) Our engines do not include belts, hoses, sending units, air compressors, flywheel, fan blade, remote oil coolers, starter, alternator or any special drive units. The engine will be dyno tested checking horsepower, RPM and oil pressure. All phases of the governor, valve train and fuel injection system will be adjusted to OEM specifications.
