Main Bearings, .040 Case, .010 Crank, .080 Thrust

OVERVIEW

When it comes to a precision air-cooled engine rebuild, the foundation of your rotating assembly is only as good as the bearings you choose. These EMPI Silverline main bearings are engineered for the serious engine builder who is resurrecting a classic Volkswagen powerplant that has seen its fair share of miles. Specifically designed for cases that have undergone significant machining, these bearings feature a .040 case over-bore, a .010 crankshaft under-size, and a .080 thrust cut. This specific combination is often the "saving grace" for vintage magnesium or aluminum engine cases that require a deeper line-bore to ensure a perfectly straight and round bore. By utilizing a steel-backed design, these bearings provide superior heat dissipation and structural integrity, ensuring that your oil pressure remains stable even under the high-temperature demands typical of the VW flat-four architecture.

Choosing the right bearing set is the difference between an engine that lasts 100,000 miles and one that fails during the break-in period. These Silverline bearings are a favorite among the specialists at Appletree Auto because they maintain tight tolerances and offer the durability required for both daily drivers and weekend warriors. Whether you are rebuilding a 1600cc dual-port for a Beetle or a torquey powerplant for a heavy Transporter, these bearings provide the necessary clearance and surface area to support the crankshaft journals effectively. The .080 thrust cut is particularly vital for cases where the thrust surface has been pounded out or "hammered" over decades of clutch engagement, allowing you to machine the case back to a fresh, flat surface and restore the longitudinal play of the crank to factory specifications.

FITMENT

These main bearings are designed for VW Type 1, 2, and 3 engines (1300cc, 1500cc, and 1600cc based). Please verify your case and crank machining dimensions before ordering.

• Volkswagen Beetle: 1966-1977 (Standard & Super Beetle)
• Volkswagen Karmann Ghia: 1966-1974
• Volkswagen Bus / Type 2: 1963-1971 (1500cc & 1600cc models)
• Volkswagen Thing / Type 181: 1973-1974
• Volkswagen Squareback, Fastback, Notchback / Type 3: 1966-1973
• Custom Applications: Sand Rails, Dune Buggies, and Trikes utilizing a Type 1 upright engine configuration.

SPECS

• Brand: Silverline (Distributed by EMPI)
• Part Number: 111-198-483OS+2
• Case Bore Size: .040 inches (1.00mm Over)
• Crankshaft Journal Size: .010 inches (0.25mm Under)
• Thrust Surface Size: .080 inches (2.00mm Over)
• Material: High-Quality Steel-Backed Alloy
• Engine Type: VW Air-cooled Type 1, 2, and 3
• Oil Hole Configuration: Pre-drilled for standard oiling circuits
• Bearing Count: Complete set for one engine

PRO TIPS

1. Always Measure Twice Before Assembly

In the world of air-cooled VWs, you can never assume a case or crank is "standard." Even if you just got your parts back from the machine shop, use a high-quality micrometer and bore gauge to verify that your case is indeed cut to .040 and your crank is at .010. Installing bearings into a case that hasn''t been properly line-bored or onto a crank that hasn''t been turned will lead to immediate engine seizure. Check the "crank-to-bearing" clearance with Plastigage during a dry-fit to ensure you have the required .0015 to .003 inches of oil clearance for a long-lasting build.

2. Verify Oil Hole and Dowel Pin Alignment

One of the most common mistakes during a rebuild is failing to align the main bearing oil holes with the oil galleries in the engine case. Before snapping the case halves together, do a "test drop" of the bearings into the saddles. Ensure the dowel pins are fully seated in the bearing holes and that the oil holes in the bearings perfectly overlap the holes in the case. If the oil flow is even partially obstructed by a misaligned bearing, you will spin a bearing within minutes of the first startup. Also, ensure the thrust bearing (the one with the flanges) is seated correctly on the flywheel end of the case.

3. Clean the Case Thoroughly After Line-Boring

Since these bearings are designed for a case that has been bored .040 over, your engine case has recently seen a lot of "metal surgery." Machine shops often leave behind microscopic magnesium or aluminum shavings in the oil galleries. Before you install these Silverline bearings, you must "rifle clean" every single oil passage with a brush and solvent, followed by high-pressure compressed air. Any debris left behind will be trapped behind your new bearings or sent directly into your crankshaft journals, instantly ruining your investment. A clean case is the only way to ensure these precision bearings can do their job effectively.