Fitting Instructions - Hydraulic Valve Lifters UV11163PA

Prestige Parts Hydraulic Valve Lifters are self-priming and must be fitted un- primed. Before you fit the valve lifters to the engine de-prime them fully to remove any oil. Excessive hydraulic pressure within the lifter may cause damage to the lifter and/or camshaft on initial start-up. When starting the engine it is normal for the valve lifters to clatter for one or two minutes until the engine has primed the lifters to the optimum pressure via the pushrod.

Before fitting, the lifter and camshaft should be liberally coated externally with hypoid oil such as EP90. The lifters should move easily in the lifter block both vertically and rotationally.

Hydraulic lifter failure is usually caused by lack of rotation. Lifter rotation depends upon the relationship of the radius on the lifter base and the degree of taper on the camshaft lobe. It is not enough to check the camshaft visually, as in order to rotate new tappets require a taper on the camshaft lobe of between 5'-7' of one degree. This is not visible to the naked eye and lobes that appear good may not demonstrate the correct degree of taper, particularly if the camshaft is not new. Lifters that do not rotate will fail within a few hundred miles, necessitating replacement of the lifters and possibly the camshaft.

Before replacing the central engine cover use the starter motor to turn the engine over, allowing you check that all the lifters are rotating. Any wear in the camshaft lobes is likely to prevent lifter rotation. When starting the engine for the first time, do not run at fast idle. As soon as the engine is running reduce idling speed to 600-700 rpm. This will allow engine oil to reach all parts of the engine without placing undue stress on new components.

*Important note: Prestige Parts® Hydraulic Valve Lifters follow the original specifications and it is recommended that they be fitted with a reprofiled or new camshaft (such as a Prestige Parts® camshaft) with the appropriate taper machined on the camshaft lobe. The rear of the lobe should exceed the front of the lobe by 0.0015”-0.0020” (0.038-0.051 mm). Regardless of this, physical observation of rotation of all the lifters remains important.