Rocker Arm Shim Set, .015 Thick, 19.5mm, Set of 8

OVERVIEW

When you are building a high-performance air-cooled VW engine, precision is the definitive line between a motor that lasts for decades and one that fails within the first few hundred miles. These EMPI Rocker Arm Shims are essential components for any engine builder looking to perfect their valvetrain geometry. When you upgrade to high-lift camshafts, performance cylinder heads, or heavy-duty rocker shafts, the factory spacing is almost never sufficient to keep the rocker arms perfectly centered over the valve stems. By utilizing these .015-inch thick shims, you gain the ability to fine-tune the lateral position of each rocker arm on the shaft. This ensures that the rocker tip makes contact exactly where it should, preventing uneven wear on the valve guides and protecting your valve stems from side-loading forces that can lead to catastrophic failure. At Appletree Automotive, we know that the smallest details often yield the biggest results in reliability and power.

This set of eight precision-ground steel shims is designed to fit standard and high-performance 19.5mm rocker shafts. They are particularly vital when using "solid" rocker shafts, which eliminate the stock wavy washers and springs in favor of a more stable, shimmed arrangement. Proper shimming allows you to set the exact side-play of the rocker arms, typically aiming for a range that minimizes mechanical noise while ensuring there is no binding as the engine reaches operating temperature. Using these shims helps maintain a consistent oil film between the rocker and the shaft by preventing the rocker from "walking" or shifting under high RPM loads. Whether you are refreshing a stock 1600cc dual-port or assembling a high-revving stroker motor, these EMPI shims provide the professional-grade accuracy required for a blueprinted engine build. Don''t settle for "close enough" when it comes to your valvetrain; use the right tools to ensure every component is aligned for maximum efficiency.

FITMENT

These rocker arm shims are designed for the standard 19.5mm rocker shafts found in the following air-cooled Volkswagen applications:

• Volkswagen Type 1: Beetle and Bug (1954-1977)
• Volkswagen Super Beetle: (1971-1979)
• Volkswagen Type 2: Bus, Transporter, Kombi (1955-1971 with Type 1 engine)
• Volkswagen Type 3: Fastback, Squareback, Notchback (1962-1973)
• Volkswagen Karmann Ghia: (1956-1974)
• Volkswagen Type 181: Thing (1973-1974)
• Custom Builds: Fits all 1200cc, 1300cc, 1500cc, and 1600cc based air-cooled engines using standard diameter rocker shafts.

TECHNICAL SPECIFICATIONS

• Thickness: .015 inches (0.38mm)
• Internal Diameter (ID): 19.5mm (Standard VW Rocker Shaft Size)
• Material: Hardened High-Tensile Steel
• Quantity: Set of 8 Shims
• Manufacturer: EMPI
• Part Number: 21-2167-0
• Application Type: Valvetrain Geometry and Side-Play Adjustment

PRO TIPS FROM THE SHOP

1. Measuring Your Side-Play Correctly

When installing these shims, especially on solid rocker shafts, you must use a feeler gauge to measure the gap between the rocker arm and the shaft support stands. For most high-performance applications, we recommend a side-play of .004 to .006 inches. If the fit is too tight, the rocker arm may bind as the metal expands with heat; if it is too loose, you will experience excessive valvetrain "clatter" and potential oil pressure loss at the rocker assembly. Always check each rocker individually, as manufacturing tolerances in the heads and shafts can vary from one cylinder to the next.

2. Centering the Rocker Tip

The primary goal of shimming isn''t just to take up space, but to center the rocker arm tip over the valve stem. Before final assembly, install your rocker shaft with the shims and rotate the engine by hand. Observe the "sweep" of the rocker arm across the valve tip. You want the contact patch to be as centered as possible. If the rocker is hitting too far to one side, move shims from one side of the rocker arm to the other to shift its position on the shaft. This prevents the valve from being pushed sideways, which is the leading cause of premature valve guide wear in performance VW engines.

3. Deburring and Lubrication

Before