Cummins 4B

A solid, high-torque, low-RPM six-cylinder engine, the Cummins B-Series is found in many over-the-road and industrial applications. Pilot Engines offers engines specific to your applications. The goal is to provide an engine with little to no modification required at install ensuring you are back on the road faster.

The 4B/3.9L Cummins is a popular engine used in step van applications including bread, snack, uniform, and other commercial delivery vehicles. This engine is also used in various industrial and construction applications.

Reviva utilizes torque plating methods for boring and honing to ensure block straightness, which reduces break-in time and crankcase pressure. In addition, Reviva uses OEM or equivalent pistons, rings, bearings, valves and gaskets, making sure that this engine will stand the test of time. 

All Reviva engines are assembled in the USA.

Product Bulletin


To determine correct part number and configurations available, please gather the following information from the valve cover: 

  • Original Engine Serial Number
  • Original Engine CPL

Complete Drop-In

  • Block
  • Rods
  • Crank Gear
  • Piston Assemblies
  • Crankshaft
  • Camshaft
  • Cylinder Head
  • Rear cover & seal
  • Oil Filter Assembly
  • Water Pump
  • Side cover/ crankcase breather
  • Llifters, Pushrods, & Rocker Arms
  • Lift pump
  • Low & High Pressure Lines
  • Intake Cover
  • Intake Connection
  • Oil Pump
  • Cam gear
  • Front Gear Housing
  • Oil Pan
  • Oil Pick-up Tube
  • Thermostat
  • Thermostat Housing
  • Gear Cover & Seal
  • Air Crossover Tube*
  • Turbocharger*
    * where required     
  • Valve Cover(s)
  • Injection Pump
  • Injectors
  • Damper Pulley
  • Exhaust manifold
  • Gasket Set
  • Oil Cooler

Dynomometer Testing

All of Reviva’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.

Warranty Coverage

On-Road Complete Drop-In configurations: 2yr/unlimited mileage. 
**2nd year long block coverage only. 
Off-Road Long Block or Complete Drop-In configurations: 1yr/2,000 hours. 
On-Road Long Block configuration: 1yr/unlimited miles.  Transit applications: 1 year. 

Some restrictions apply; see limited warranty details or call for more information.