Main Bearings, .040 Case, .020 Crank, .040 Thrust

OVERVIEW

When you are deep into a performance engine build or resurrecting a classic Volkswagen powerplant that has seen decades of service, precision is the only language that matters. These EMPI Silverline Main Bearings are engineered specifically for those "difficult" cases and crankshafts that require significant machining to return to a true, circular state. If your engine case has been bored .040 inches (1.0mm) over and your crankshaft journals have been ground .020 inches (0.50mm) under, these bearings provide the exact tolerances needed to restore oil pressure and ensure a smooth-running rotating assembly. Utilizing a robust steel-backed construction, these bearings offer superior heat dissipation and structural integrity, preventing the "spinning" or "crushing" often seen in inferior, soft-material bearings during high-RPM operation.

What sets this specific set apart is the inclusion of the .040 (1.0mm) thrust cut. In the world of air-cooled VW engines, the thrust surface of the engine case often takes a beating, leading to excessive crankshaft end-play that can destroy a build before it even clears the break-in period. By machining the thrust face of the case and utilizing these specialized bearings, you effectively "reset" the engine''s geometry to factory-fresh specifications. Whether you are building a high-torque 1776cc street engine or a reliable 1600cc stocker for your weekend cruiser, these Silverline bearings provide the metallurgical consistency and dimensional accuracy that professional engine builders demand. Don''t compromise your entire investment by using anything less than the industry standard for oversized engine restoration.

FITMENT

These main bearings are designed for Volkswagen Type 1 based engines (1300cc, 1500cc, and 1600cc) with specific machining requirements. They fit the following models provided the case and crank have been cut to the specified dimensions:

• Volkswagen Beetle: 1961-1977 (Standard & Super Beetle)
• Volkswagen Karmann Ghia: 1961-1974
• Volkswagen Bus / Type 2: 1961-1971
• Volkswagen Type 3 (Squareback, Fastback, Notchback): 1961-1973
• Volkswagen Thing / Type 181: 1973-1974
• Custom Applications: Dune Buggies, Sand Rails, and Trikes utilizing Type 1 upright engines.

SPECS

• Brand: Silverline (Distributed by EMPI)
• Part Number: 111-198-485OS
• Case Bore Diameter: .040 inches (1.0mm) Oversize
• Crankshaft Journal Diameter: .020 inches (0.50mm) Undersize
• Thrust Surface Width: .040 inches (1.0mm) Oversize
• Material: Steel-backed with high-quality Babbitt lining
• Construction: Three-piece main bearing set plus center and cam-end bearings
• Manufacturing Origin: High-precision manufacturing for consistent oil clearance

PRO TIPS

Tip 1: Triple-Check Your Machinist''s Work. Before you ever apply assembly lube, you must verify the dimensions of your case and crank with a high-quality micrometer and dial bore gauge. While a box might say .040 case and .020 crank, human error during machining is always a possibility. Ensure your oil clearances fall within the .0015 to .003 inch range for a street engine. If the clearances are too tight, you risk "seizing" the bearing; if they are too loose, you will suffer from low oil pressure at operating temperatures. Never assume the parts and the machining match without physical verification.

Tip 2: Align the Oil Holes and Dowel Pins. One of the most common mistakes during air-cooled VW engine assembly is failing to properly seat the main bearings on the case dowel pins. If the bearing is not perfectly seated, the case halves will not torque down correctly, and you will likely crush the bearing shell. Always do a "dry fit" of the crank into one case half. Visually inspect that the oil holes in the bearing shells align perfectly with the oil galleries in the case. Any obstruction here will result in immediate bearing failure due to oil starvation.

Tip 3: The Importance of End-Play Measurement. Because these bearings feature a .040 thrust cut, you are likely dealing with a case that has had its thrust face machined. Once the case is torqued to spec with the crank installed (but before the heads or pistons are on), you must measure your crankshaft end-play using a dial indicator. Your target should typically be between .003 and .005 inches. Adjust your flywheel shims accordingly. Using a .040 thrust bearing gives you the "meat" needed to fix a damaged case, but it requires diligent shim selection to ensure the crank doesn''t walk back and forth under clutch pressure.