These Cummins 39947759 Lifters or Tappets are a recommended replacement item when installing a High Performance Camshaft in your Cummins 5.9L or 6.7L Turbo Diesel engine. The OEM replacement tappets are sold as a complete set of 12 3931623 tappets for the 6BT 5.9L or 8 tappers for the 4BT 3.9L Cummins diesel engine.
Cummins 3931623 OEM Replacement Lifters or Tappets
Cummins 3931623 Factory Replacement Tappet for the 3.9L and 5.9L Cummins Diesels.
The Cummins 3931623 Lifters - Tappets Cummins for 1989 to 1998 Cummins Turbo Diesel. These OEM Cummins tappets are for use on the Cummins 3.9L and 5.9L Turbo Diesel engines. This Cummins 3931623 Tappet is the Original Equipment Manufacturer part. This OEM Tappet is the same tappet that was made and installed by Cummins at the factory.
These OEM Cummins Tappets are a complete set of replacement tappets for your engine:
- 8 Tappets for a Cummins 3.9L 4BT Diesel engine.
- 12 Tappets for a Cummins 5.9L 6BT Diesel engine.
These Cummins 3931623 Lifters, Tappets are a recommended replacement when installing a High Performance Camshaft in your Cummins Turbo Diesel engine. Installation of these new Cummins 3947759 3.9L 4BT Series and 5.9L 6BT Series engines Tappets are for high horsepower and High RPM engine builds or modifications. These Cummins tappets have a larger cam footprint than the stock eight and twelve Cummins Tappet. The more substantial contact of the Cummins tappet is used to ensure constant contact with a modified camshaft profile as the engine revolutions are increased. Using old tappets on a new camshaft could cause uneven wear on the camshaft itself. These Cummins tappets sold as a complete set of eight or twelve tappets required for your modification.
The term tappet is widely used in relation to internal combustion engines. It is most commonly encountered as a maintenance task for overhead valve engines, that of 'adjusting the tappets'. This operation improves the overall clearance in the valve actuation system: typically 20 thousandths of an inch (0.5 mm). The name arises because it is the clearance of the tappets that is adjusted, even though the adjustment is not made to the tappets themselves.
Strictly speaking, the tappet is that part also termed a cam follower that runs on the camshaft and is made to move vertically by the action of the rotating cam. In an overhead valve engine, this tappet is fitted down in the engine block. From there it drives a long thin pushrod, up to the top of the engine, above the cylinder head. Here the rockers, arranged on a rocker shaft beneath the rocker cover, reverse the direction of the valve movement to press the valves downwards to open them.