PERFORMANCE TAPPET ASSEMBLIES FOR MOST MODELS

Weight: 0.33

• These performance tappets offer premium performance, strength and reliability at a reasonable price
• Made of high strength steel alloy and heat treated for strength and wear resistance
• The internal parts are machined to tolerances for long lasting use
• Sold Each

Types of Hydraulic Lifters:

OEM Design: These lifters are manufactured to be direct replacements for the original equipment. They have the same range of Leak Down as was supplied to your OE lifter. These lifters are made with the widest Leak Down range of 10 to 120 seconds. The reason for this range is to ease manufacturing and reduce the cost of the part. We manufacture this type of part to the same range as was supplied to the OEM.

Pro Street Design: These lifters have a Leak Down on the upper end of the scale from 90 to 120 seconds. In a performance application, these lifters will actually act like a mechanical lifter with very little effective loss of valve lift or duration at any RPM. They also have a positive retainer instead of the OEM wire clip design. These lifters are very hard to produce because the TOTAL clearance between the I.D. of the Body and Piston assembly is reduced to less than 0.000120" or 1/30 of a human hair. These are like super heavy-duty shocks and can handle higher spring pressures without collapsing like the OEM and Race lifters.

Race Design: These lifters have a Leak Down on the lower end of the scale from 8 to 10 seconds. In the performance application, these lifters will actually "Bleed" down and result in an effective loss of valve lift and duration at lower RPM's. These are also referred to as "Variable Duration" Lifters and will supply a better idle quality when using a performance cam, while still getting the benefit of the upper end power over a stock cam. As the engine increases in RPM the Bleed down effect is reduced, resulting in more duration and valve lift. These lifters have a positive retainer instead of the OEM wire clip design. Don't be fooled, and make sure they are manufactured as Fast Leak lifters and not just a stock lifter with a nice retainer.
POWER HOUSE
.8425" STD O.D.
OEM Design Hydraulic Tappet
Fits Big Twin Evolution 1984/1999 & Sportster 1986/1990
Replaces HD# 18523-86