Johnson Lifters Tech Briefs and Lifter Usage Guide
  • Consult cam card for specs
  • Rotate engine to exhaust valve opening
  • Adjust intake
  • Rotate engine to intake valve closing
  • Adjust exhaust

Hydraulic Lifters vs Mechanical Lifters

Each type of lifter takes a distinctly different approach to the same task; transferring rotary cam motion to linear motion to operate the valve. Both lifter types have a pushrod seat that is held in place by a retaining clip. The mechanical or (solid lifter) pushrod seat sits on an internal step in the lifter body and does not move, thus the term solid lifter.

The pushrod seat in a hydraulic lifter sits on top of a movable plunger that operates like a miniature hydraulic pump. Below the plunger, a spring-loaded valve moves the pushrod seat upward, filling the reservoir and pressing against the pushrod when the cam lobe is on the base circle. A retaining clip at the top limits the travel of the internal plunger.

Solid lifters require a running clearance or "valve lash” to accommodate thermal expansion.  Hydraulic lifers have no valve lash and the pushrod remains loaded against the oil pressure in the hydraulic reservoir via a “preload” of .015 to .0075-inch. This eliminate the clattering noise associated with solid lifters.

Each lifter type has its place in the performance world depending on the application. Solid roller lifters are still the predominant lifter type for high rpm racing applications. Hydraulic roller lifters now dominate contemporary street performance use and flat tappet hydraulic and solid lifters are still the choice for standard low-buck applications.

In every case, Johnson's "extra-precision" technology makes Johnson Lifters the popular choice for maximum performance.

Flat Tappet vs Roller Tappet Lifters

Roller tappet lifters are used almost exclusively in OEM production vehicles. They have proved superior in virtually every case. Their advantages include silent operation, reduced friction and wear, higher tappet velocity, more lift and more area under the curve, higher available rev range and the ability to deal with higher spring pressures. They are reusable and can be swapped to different cam lobes. They permit cam changes without the expense of new lifters and they can be rebuilt. Roller lifters are initially more expensive, but they are cost effective in terms of longevity and the additional versatility and performance they provide.

Short Travel Hydraulic Lifters

Short travel hydraulic lifters are specifically used for racing classes that mandate the use of hydraulic lifters. They have reduced plunger travel and thus act more like a solid lifter while maintaining the required hydraulic configuration. This type of lifter still incorporates preload and provides hydraulic function, but it it acts more like a solid lifter because it pumps up more rapidly. In a sense, it accomplishes the same task as setting a regular hydraulic lifter to zero lash plus a quarter turn down.

 

Johnson Lifters® products are covered by a general warranty that states that its products will be free from manufacturing defects in materials and workmanship. The length of this warranty for automotive parts is as follows: Johnson Lifters are guaranteed for the life of the engine and will be replaced if any failure is deemed due to manufacturing defect and sold under the Johnson Lifters® name.

All Johnson Lifters warranties assume that the product(s) were properly installed, subjected to normal use and service and that they have not been modified, neglected or used on racing or competition applications. The warranty covers only the product itself and not the cost of installation and/or removal or any claim of collateral damage.

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