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

OVERVIEW

When you are deep into a performance engine build or a high-mileage restoration, precision isn''t just a goalit is a requirement. These EMPI main bearings, manufactured to the highest standards, are designed specifically for air-cooled Volkswagen engines where the case has been line-bored and the crankshaft has been turned. In the world of VW engine machining, finding the right bearing combination is the difference between a motor that lasts 100,000 miles and one that fails in the first 500. This specific set features a .020 case over-size and a .020 crankshaft under-size, making it the perfect solution for salvaging a seasoned magnesium or aluminum case and a forged crank that both require significant machining to return to a perfectly round and concentric state. By utilizing these high-quality bearings, you are ensuring that your oil clearances are exact, which maintains critical oil pressure and prevents premature wear on your rotating assembly.

What sets this particular bearing set apart is the massive .080 thrust cut. For many air-cooled enthusiasts, the thrust surface of the engine case is the first point of failure; once the crankshaft begins to "walk" forward and backward, it beats the case into submission, often rendering it useless. However, with a .080 thrust cut, a skilled machinist can fly-cut the thrust face of the case to a fresh, flat surface, allowing you to save a numbers-matching or high-performance case that would otherwise be scrap. These bearings are produced with a steel-backed construction and a high-grade babbitt lining, providing the ideal balance of embeddability and fatigue strength. Whether you are building a 1600cc daily driver or a larger displacement stroker motor, these bearings provide the structural foundation necessary to handle the thermal expansion and high-revving demands of the classic flat-four powerplant.

FITMENT

This bearing set is designed for Type 1 based engines (1300cc, 1500cc, and 1600cc) with a line-bored case and a turned crankshaft. Please verify your machinist''s measurements before ordering.

• Volkswagen Beetle: 1966-1977 (Sedan & Convertible)
• Volkswagen Super Beetle: 1971-1979
• Volkswagen Karmann Ghia: 1966-1974
• Volkswagen Bus / Transporter: 1963-1971 (Type 2 with Type 1 based engine)
• Volkswagen Thing: 1973-1974
• Volkswagen Squareback, Fastback, Notchback: 1966-1973 (Type 3)
• Custom Applications: All Sand Rails, Dune Buggies, and Trikes using a VW Type 1 engine case.

SPECS

These technical specifications are critical for ensuring your engine block and crankshaft machining match the bearing requirements.

• Brand: EMPI / Mahle (Premium Quality)
• Case Bore (Outside Diameter): .020 inches (0.50mm) Oversize
• Crankshaft Journal (Inside Diameter): .020 inches (0.50mm) Undersize
• Thrust Surface: .080 inches (2.00mm) Oversize
• Material: Steel-backed with high-grade babbitt alloy lining
• Engine Type: VW Type 1, 2, and 3 (1300cc-1600cc based)
• Oil Holes: Pre-drilled for standard oiling configurations
• Part Number Cross-Reference: 111-198-475OS+2

PRO TIPS

1. Verify Your Machinist''s Work with a Micrometer

Never take it for granted that your case or crank matches the box until you have measured it yourself. Before installing these bearings, use a high-quality micrometer to measure your crankshaft journals and a dial bore gauge to check the line-bore in the case. For a .020/.020/.080 set, your crank journals should be precisely 0.50mm smaller than stock, and your case bore should be 0.50mm larger. Measuring the thrust width is especially critical with a .080 cut, as this is a non-standard, heavy-duty cut that requires specific machining of the number one main bearing saddle to ensure the bearing seats fully and doesn''t bind against the crank.

2. Check Oil Hole Alignment and Dowel Pin Seating

One of the most common mistakes in VW engine assembly is assuming the oil holes in the bearings perfectly align with the oil galleries in the case. Always dry-fit your bearings into the case halves without the crank first. Check that the oil holes are clear and that the dowel pins are properly seated. If a dowel pin is too long or the hole in the bearing isn''t deep enough, it will "high-spot" the bearing, causing it to pinch the crankshaft once the case halves are torqued. This leads to immediate bearing failure upon startup. If necessary, you can lightly chamfer the oil holes for improved flow, but always ensure the area is surgically clean afterwards.

3. The Importance of Proper Assembly Lube and Cleanliness

Because you are working with an oversize thrust bearing (.080), you are likely dealing with a case that has seen significant machine work. This means there is a high probability of metal shavings hiding in the oil galleries. Scrub the case with hot soapy water and use rifle brushes to clean every internal passage before assembly. When it comes time to install, use a dedicated high-pressure assembly lubricant on the bearing faces. Do not just use standard motor oil, as it can run off the surfaces during the time it takes to finish the build. The assembly lube provides the necessary protection for those first few critical seconds of "dry" rotation before the oil pump primes the system and creates the hydrodynamic wedge required for operation.