Main Bearings, .040 Case, .030 Crank, .040 Thrust

OVERVIEW

When it comes to rebuilding a classic air-cooled Volkswagen engine, precision is the difference between a motor that lasts for decades and one that fails within the first hundred miles. These EMPI Main Bearings are engineered for high-mileage cases and crankshafts that have undergone significant machining to restore structural integrity. If your engine case has been line-bored to .040 inches (1.00mm) and your crankshaft has been ground down to .030 inches (0.75mm) undersize, this bearing set is the essential component needed to bring your tolerances back to factory specifications. Designed to handle the unique thermal expansion characteristics of the VW magnesium or aluminum alloy case, these bearings provide a stable surface for the crankshaft to rotate, ensuring consistent oil pressure and reduced friction during high-heat operation.

This specific set is often referred to as a "problem solver" kit because it accommodates a .040 inch (1.00mm) thrust cut. Over years of clutch engagement, the thrust surface of a VW engine case often becomes hammered or worn, requiring a machinist to cut the thrust face back to a smooth, flat surface. By utilizing these .040 thrust bearings, you can salvage a rare or original engine case that would otherwise be destined for the scrap heap. At Appletree Automotive, we understand that every thousandth of an inch matters. That is why we offer these high-quality EMPI bearings, which feature the correct oil hole alignments and dowel pin recesses to ensure a seamless installation process during your Type 1, Type 2, or Type 3 engine build. Don''t settle for inferior internals when your engine''s longevity is on the line.

FITMENT

These main bearings are designed for the Volkswagen Type 1 based engine platform. Please verify your machinist''s measurements before ordering.

• Volkswagen Beetle: 1961-1979 (1300cc, 1500cc, and 1600cc engines)
• Volkswagen Super Beetle: 1971-1979
• Volkswagen Karmann Ghia: 1961-1974
• Volkswagen Bus / Transporter: 1961-1971 (Type 1 upright engine style)
• Volkswagen Thing (Type 181): 1973-1974
• Volkswagen Type 3 (Squareback, Fastback, Notchback): 1961-1973
• Custom Applications: Dune Buggies, Sand Rails, and Trikes utilizing a VW Type 1 engine case.

SPECS

These technical specifications are critical for ensuring your engine block and crankshaft have been machined to the correct dimensions to accept this bearing set.

• Brand: EMPI / High-Quality Replacement
• Case Bore (Oversize): .040 inches (1.00mm) - Requires the engine case to be line-bored.
• Crankshaft Journal (Undersize): .030 inches (0.75mm) - Requires the crankshaft to be turned/ground.
• Thrust Surface (Oversize): .040 inches (1.00mm) - Requires the case thrust face to be machined.
• Material: Steel-backed with a high-durability babbitt or aluminum alloy lining for superior oil retention.
• Part Number: 111-198-487OS
• Engine Type: VW Air-cooled Type 1, 2, and 3 (Dual Relief or Single Relief Cases).
• Configuration: Standard 4-piece main bearing set including the specialized thrust bearing.

PRO TIPS

1. Always Perform a "Dry Fit" Measurement

Before applying any assembly lube or final sealant to your case halves, place your crankshaft into the case with the bearings installed and torque the case to about 15-20 ft-lbs. Use a dial indicator to check your crankshaft end play and ensure the crank spins freely by hand. If there is any binding, it usually indicates that the line bore was not perfectly straight or there is a burr on the bearing saddle. It is much easier to find and fix these issues before the engine is fully assembled and sealed with RTV or Curil-T. Don''t assume the machinist got it perfect; always verify the clearances yourself.

2. Align the Oil Holes and Dowel Pins Perfectly

One of the most common mistakes in VW engine assembly is failing to properly seat the bearing on the dowel pin. If the bearing is not perfectly aligned, the dowel pin will crush the bearing shell when the case is torqued, leading to immediate engine failure upon startup. When installing these EMPI bearings, feel for the "click" as the bearing seats onto the pin. Additionally, double-check that the oil holes in the bearings align perfectly with the oil galleries in the case. If the oil flow is restricted even slightly, you will experience premature bearing wear and a localized "hot spot" on the crankshaft journal.

3. Clean the Bearings and Case Saddles Thoroughly

Even though these bearings come new in the box, they often have a protective shipping film or micro-dust from the manufacturing process. Use a lint-free cloth and a bit of brake cleaner to wipe down the back of the bearing and the case saddle where it will sit. Any tiny speck of dirt trapped between the bearing and the case will create a high spot on the bearing surface once the case is torqued. This high spot will rub against the crankshaft, creating friction and heat. Once clean, apply a high-quality assembly lube ONLY to the inner surface (the side that touches the crank), never to the back side of the bearing that sits in the case.