Installation Instructions for 20800, 20810 & 20820 Retrofit Hydraulic Roller Lifter

Thank you for choosing JEGS hydraulic roller lifters. These lifters are engineered and manufactured to provide optimum performance and reliability. In order to take full advantage of the product, proper installation is required. Please follow the instructions below to insure complete satisfaction.

Pre-installation Considerations

Since the valve train in a typical overhead valve engine contains numerous components which may or may not be matched, care must be taken to avoid potential issues which may affect the overall performance of the lifters and the engine. These considerations can be best described in two categories: Mechanical Interference and Valve Train Geometry.

Mechanical Interference

Mechanical interference can occur between the various components which may lead to engine damage and failure. These potential problem areas must be checked prior to final adjustment of the lifters and operation of the engine. The following is a list of areas to consider:

• Piston to valve clearance

• Rocker arm slot to stud clearance

• Rocker arm to valve spring retainer clearance

• Valve spring retainer to guide/seal clearance

• Valve spring coil bind height

Valve Train Geometry

Proper overall valve train geometry must be maintained in order to optimize valve motion. The following can affect the geometry of the valve train:

• Deck height of block

• Cylinder head heights

• Camshaft lobe base circle diameter

• Seat height in lifter

• Pushrod length• Rocker arm configuration

• Valve length

The simplest way to achieve the correct geometry and compensate for un-matched parts in the valve train is by using proper pushrod length. Table 1 provides the lengths for the most common applications. If you are unsure of the required pushrod length, refer to the Pushrod Length Procedure, otherwise, proceed to Installation Procedure.