Main Bearings, .020 Case, .010 Crank, .080 Thrust

OVERVIEW

Building a reliable air-cooled engine requires more than just high-quality parts; it requires the exact tolerances that only premium main bearings can provide. These EMPI main bearings are engineered for those specific ''save-a-case'' scenarios where the engine block has been line-bored .020 inches over and the crankshaft journals have been precision-ground .010 inches under. By utilizing high-grade materials and the legendary manufacturing standards often associated with the Mahle brand, these bearings ensure that your oil pressure remains stable and your rotating assembly spins with minimal friction. Whether you are restoring a vintage Beetle for daily driving or building a rugged sand rail for the dunes, these bearings provide the structural foundation necessary to handle the heat and stress inherent in the Volkswagen flat-four design.

One of the standout features of this specific set is the .080-inch oversized thrust surface. In the world of VW engine building, the thrust flange on the engine case often takes the most abuse, leading to excessive crankshaft end-play if not properly addressed. A .080-inch (2.00mm) thrust cut is a significant machining step that allows you to salvage a rare or valuable magnesium or aluminum case that would otherwise be destined for the scrap pile. By choosing these precision-machined bearings, you are investing in the longevity of your engine, ensuring that the crankshaft stays perfectly indexed even under heavy clutch loads. Don''t settle for ''close enough'' when it comes to your bottom end; trust the components that professional builders use to keep their Volkswagens on the road for decades.

FITMENT

• Volkswagen Type 1: Beetle, Bug, and Super Beetle (1961-1979)
• Volkswagen Type 1: Karmann Ghia (1961-1974)
• Volkswagen Type 2: Bus, Transporter, Station Wagon (1961-1971)
• Volkswagen Type 3: Squareback, Fastback, Notchback (1962-1973)
• Volkswagen Thing: (1973-1974)
• Engine Displacements: 1200cc (40hp), 1300cc, 1500cc, and 1600cc based upright engines

SPECS

• Brand: EMPI / Mahle (Brazilian)
• Case Bore (Oversize): .020 inches (0.50mm)
• Crankshaft Journal (Undersize): .010 inches (0.25mm)
• Thrust Flange (Oversize): .080 inches (2.00mm)
• Material: High-strength steel-backed bimetal alloy for superior load-bearing capacity
• Compatibility: Standard Type 1 engine cases (Magnesium or Aluminum)
• Part Number: 111-198-473OS+2
• Application: Main crankshaft support for air-cooled VW engines

PRO TIPS

1. Verify Your Machining Dimensions

Before you even open the plastic packaging of your new bearings, you must verify the work done by your machine shop with a high-quality micrometer and dial bore gauge. Machine shops can occasionally make mistakes, and installing a .020 case bearing into a .040 bore will lead to immediate oil pressure failure. Measure the main journals on your crankshaft to ensure they are exactly .010 under, and check the case web bores to confirm the .020 line-bore. Finally, ensure the thrust surface was cut specifically to .080. Proper verification at this stage prevents a catastrophic engine failure during the first start-up.

2. Critical Dowel Pin Alignment

When installing the bearings into the case halves, pay extremely close attention to the dowel pins. It is a common mistake for novice builders to accidentally "crush" a bearing because it wasn''t perfectly seated over the pin. This not only ruins the bearing but can also damage the engine case. Ensure the oil holes in the bearings align perfectly with the oil galleries in the case. Use a small amount of assembly lube to hold the bearings in place during the mock-up, and always rotate the crank by hand after torquing the case halves to ensure there is no binding or resistance.

3. Manage Your End-Play Correctly

Because these bearings feature a .080 oversized thrust, you are likely working with a case that has seen significant wear. After the case is torqued to spec with the crankshaft installed, you must measure your crankshaft end-play using a dial indicator. The target range for a street engine is typically .003 to .005 inches. Since the thrust bearing is oversized, you may need to utilize specific shims behind the flywheel to achieve this tolerance. Never skip this step; improper end-play will lead to premature bearing wear and can eventually "pound out" the thrust surface of your engine case again.