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

OVERVIEW

When you are deep into a high-quality engine rebuild, the foundation of your entire build rests on the precision of your main bearings. These EMPI Main Bearings are specifically engineered for Volkswagen air-cooled Type 1, 2, and 3 engines where the engine case has been line-bored .040 inches (1.0mm) over and the thrust surface has been machined .040 inches (1.0mm) to restore a perfectly flat mating surface. Despite the heavy machining to the case, these bearings are designed for a standard-sized crankshaft, making them the perfect solution for a builder who is reusing a pristine, factory-spec crank or a brand-new counterweighted standard journal crankshaft. High-performance air-cooled engines demand tight tolerances to maintain consistent oil pressure, and these steel-backed bearings provide the structural integrity needed to prevent bearing "squish" under high RPM loads.

Choosing the correct bearing size is often the most critical step in the machining process at Appletree Automotive. These Silverline-style bearings feature a high-quality steel backing with a specialized alloy lining that offers superior embeddability, allowing tiny particles of debris to sink into the bearing surface rather than scoring your expensive crankshaft journals. Because these bearings accommodate a .040 case cut and a .040 thrust cut, they are often the "saving grace" for vintage magnesium or aluminum engine cases that have seen decades of use and require significant material removal to become true and square again. Whether you are building a daily driver Beetle, a rugged off-road woods buggy, or a weekend drag racer, these bearings ensure that your rotating assembly stays centered and supported for tens of thousands of miles.

FITMENT

This bearing set is designed for the 1300cc to 1600cc based air-cooled engines (Type 1, 2, and 3). Please verify your case and crank measurements before ordering.

• Volkswagen Type 1: Beetle and Super Beetle 1966-1979
• Volkswagen Type 2: Bus / Transporter 1963-1971 (1500cc & 1600cc)
• Volkswagen Type 3: Fastback, Squareback, Notchback 1966-1973
• Volkswagen Karmann Ghia: 1966-1974
• Volkswagen Thing: 1973-1974
• Custom Applications: Dune Buggies, Sand Rails, and Trikes utilizing a VW 1600cc based engine case.

SPECS

• Brand: EMPI / Silverline
• Part Number: 111-198-481OS
• Case Bore Diameter: .040 Inches (1.00mm) Oversize
• Crankshaft Journal Diameter: Standard (Factory Spec)
• Thrust Surface Width: .040 Inches (1.00mm) Oversize
• Material Construction: Heavy-duty Steel-Backed with High-Lead Aluminum Alloy
• Engine Type: VW Air-cooled Type 1, 2, 3 (Dual Relief or Single Relief Cases)
• Oil Hole Configuration: Precision pre-drilled for standard oiling circuits

PRO TIPS

1. Always Verify with a Micrometer

Never assume the labels on a box or the word of a previous owner are 100% accurate when it comes to engine machining. Before installing these bearings, you must use a calibrated micrometer to measure your crankshaft journals and a dial bore gauge to check the internal diameter of your line-bored case. If your case was bored .040 but you accidentally install .020 bearings, you will have zero oil pressure and immediate engine failure. Double-checking that the case is truly cut .040 and the thrust is cut .040 ensures that your "crank walk" is within the factory specification of .003 to .005 inches after the flywheel is torqued down.

2. The Importance of Clean Oil Passages

When an engine case is machined for a .040 line bore, metal shavings and fine particulate matter can become trapped in the internal oil galleries. Before you even think about snapping these bearings into place, you should remove all oil gallery plugs, scrub the passages with a long nylon brush and solvent, and blow them out with compressed air. Any leftover grit from the machining process will flow directly into your brand-new bearings the moment the engine fires up, destroying the soft bearing surface and potentially ruining your standard-sized crankshaft journals. Cleanliness isn''t just a suggestion; it''s the difference between a 100,000-mile engine and a 100-mile engine.

3. Proper Alignment and Dowel Pin Seating

When installing the main bearings, pay close attention to the dowel pins located in the engine case. The bearings have specific holes that must drop perfectly over these pins. It is a common mistake for builders to "almost" seat the bearing, and then force the case halves together with the case bolts. This will crush the bearing shell, distort the bore, and cause a localized hot spot that will lead to a spun bearing. Use a small amount of assembly lube to hold the bearing in place, and ensure the bearing is fully seated against the case saddle. If the case halves don''t close with light hand pressure, stop and check the alignment of your bearings on the dowel pins immediately.