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Every race car driver and truck driver hauling loads wants reliable and optimal performance when it is needed the most. Roller lifters have been used under the hood to reduce friction and increase power output. There are three main styles of roller lifters to choose from. You may already have a roller lifter installed in your vehicle that you want to replace or you may want to upgrade for better performance.

Definition

You will find roller lifters within the engines of some vehicles. A roller lifter is a valve lifter that has a metal roller attached at one end. The roller end makes contact with the camshaft, reducing friction between the camshaft lobe and lifter.

Construction

You can locate a lifter on the top of each camshaft lobe. These have a cylinder shape that is made out of metal. Each lifter will have a pushrod on the upper section of its metal body. The lifter rises, causing the pushrod to rise to actuate the adjacent rocker arm. This motion then opens up the cylinder head valve.

Application

Lifters convert the energy made by the camshaft lobes into useful energy for the engine. Roller lifters produce less friction and have a longer lifespan than regular flat lifters. Less friction will give you more engine power, thus making it a good choice for engines that need an extra boost of energy and power. These lifters are often found under the hoods of small scale race cars that need reliable engine performance.

Types of Lifters

You will find a few different types of lifters. You will find mechanical roller lifters, hydraulic roller lifters and retrofit hydraulic roller lifters as the most frequently implemented lifters. The mechanical roller lifters are usually found in street or mild competition applications. Hydraulic roller lifters are used with standard factory alignment bars where hydraulic roller lifters came factory equipped. Retrofit hydraulic rollers are specially designed for fort engines and small block engines. These have vertical alignment bars.

Reinstalling lifters in a V-8 engine is not overwhelming, but you do need to remove the intake manifold, valve covers rocker arms, pushrods and lifters before the V-8 lifters can be reinstalled. Although most technicians agree that reinstalling the lifters themselves is a straightforward job, certain tasks and tests need to be performed before the lifters in a V-8 can be reinstalled. Disassembling the engine to this level means a problem exists in the valve train.

Instructions

1

Inspect the camshaft lobes, bearings and journals, following the instructions in the vehicle manufacturers service manual, for any unusual wear and repair or replace the camshaft as needed. Lubricate the cam bearings and journals with 30-weight oil and reinstall the camshaft. This step is vital because the lifters rest on top of the lobes of the camshaft. If the lifters are reinstalled prior to the camshaft being reinstalled, the lifters will fall down into the bottom of the crankcase.

2

Have a valve lifter leakdown test performed on each lifter by a repair facility or an auto-parts store with machine shop services to ensure that the lifters will perform within factory specifications. Replace any defective lifters that do not pass the leakdown test with new lifters.

3

Clean off any carbon or sludge from the outside of the body of the lifter. Ensure that the oil holes are free of grime and sludge. Inspect the bottom of the lifter, which comes in contact with the camshaft lobe, to ensure that it is not worn or discolored. Replace any worn or discolored valve lifters.

4

Immerse the valve lifters in a 1-qt. container of 30-weight motor oil to ensure that the lifters will remain lubricated in the engine block until the engine is started. Reinstall the V-8 engines valve lifters into the holes in the engine block that are provided for the lifters by hand with the flat end of the lifter resting on the camshaft lobe. No tools are needed to reinstall the lifters in the engine block.

An internal combustion engine has hundreds of components. One of the critical components is the lifters, also called tappets. Lifters ride on the camshaft and lift the push rods. The push rod, in turn, pushes on one side of a rocker arm, like a teeter-totter. The other side of the rocker arm pushes down on the valve when the camshaft pushes up on the lifter. There are three types of lifters used in engines, and all three have their pros and cons.

Solid Lifters

Solid lifters are made of a solid rod of hardened steel. Most are about 1 inch in diameter and 2 inches in length. The bottom of the lifter rides on the camshaft, and the top has a small depression where the push rod sits. According to Ball State University, solid lifters were commonplace in the 1960s and the 1970s. The advantage to a solid lifter is that it does not lose horsepower in the process of lifting. The drawback is that the rocker arm can go out of adjustment quite often. If you hear a car engine make a clack-clack-clack-clack sound when going down the road, its because the rocker arms are out of adjustment and hammering the valves. Currently, solid lifters are used in racing engines due to the horsepower loss factor of hydraulics.

Hydraulic Lifters

A hydraulic lifter looks very similar to a solid lifter, except for one important internal difference: It is designed to be a self-adjusting shock absorber, using engine oil as the working fluid. When the camshaft lobe pushes up on the bottom of the lifter, an internal pool of oil pushes up on a piston and spring assembly. The internal piston pushes on the push rod. Due to this process, no rocker arm adjustment is needed since the lifter self-adjusts the entire valve train. The upside to hydraulic lifters is that the initial shock of contact is taken up by the oil, eliminating the constant need for rocker arm adjustment. The downside is that because it absorbs shock, the engine loses horsepower through the valve train. Moreover, hydraulic lifters have internal mechanical components that wear out, causing oil bypass or bleed-down. When it does wear out, the lifter no longer lifts. This condition is known as a "collapsed lifter."

Roller Lifters

Roller lifters are a significant advancement in automotive engine technology. Whereas a conventional lifter is cylindrical, with a flat bottom that rides on the cam lobe, a roller lifter uses a small wheel at the bottom, so the wheel rides on the cam lobe. This reduces friction significantly since the lobe does not scrape but rather rolls on the lifter. Roller lifters are available as solid lifters, for racing applications, or hydraulic, for conventional applications. The advantage of roller lifters is reduced friction at the cam. The drawback is increased cost since more manufacturing steps are involved in their production.

Building an engine piece by piece or repairing an engine can quickly become expensive. It is always helpful to find ways in which to save money. One way to do this is to reuse parts from your existing engine.

The Facts

Roller lifters are part of the valvetrain. They can be hydraulic or solid (mechanical). They roll, therefore the friction is less, and they can work well even with aggressive cam profiles.

Considerations

While you cant reuse flat lifters, roller lifters can be reused as they are designed differently and generally are subject to less friction and wear. These do not "require the lifter and cam lobe to wear-in or mate to each other," according to Summit Racing. It is important to assess whether the roller lifters you want to reuse are worn. First, check if they still roll smoothly. Also, you should clean and check the lifters for wear and discoloration from heat. You should check the needle bearings and the axle as well as the wheel. If they are worn, at best they will not work well or last very long. At worst, they can end up damaging your engine.

Significance

Roller lifters can be safely reused if you are diligent when cleaning, ensuring there are no signs of wear.