Main Bearings, .020 Case, .020 Crank, .040 Thrust

OVERVIEW

Precision is the cornerstone of any successful air-cooled engine rebuild, and these EMPI Silverline main bearings are engineered to meet the exacting demands of a professional-grade restoration. When your Volkswagen engine case has seen decades of service, the main bearing saddles often require line-boring to restore perfect concentricity, and your crankshaft may need grinding to remove scoring or taper. This specific bearing set is designed for the "double-oversize" scenario where your engine case has been machined .020 inches (0.50mm) over and your crankshaft journals have been turned .020 inches (0.50mm) under. By utilizing these high-quality steel-backed bearings, you are ensuring that your oil pressure remains stable and your rotating assembly spins with the friction-free reliability that German engineering intended.

Choosing the right thrust dimension is equally critical for the longevity of your engine''s magnesium or aluminum case. This set features a .040 inch (1.0mm) oversized thrust flange, which is essential if your case has been thrust-cut to repair damage caused by excessive crankshaft end-play. Silverline bearings are the industry standard for VW enthusiasts because they offer superior embedability and thermal conductivity, allowing small debris particles to be safely trapped within the bearing material rather than scoring the crankshaft. Whether you are building a daily-driven Beetle or a rugged off-road dune buggy, these bearings provide the structural integrity required to handle the stresses of the Type 1 engine platform. Trust Appletree Auto to provide the internal engine components that turn a standard rebuild into a high-mileage powerhouse.

FITMENT

These main bearings are designed for the Volkswagen Type 1 based engine case (1300cc, 1500cc, and 1600cc). Please verify your machining measurements before ordering.

• Volkswagen Beetle: 1966-1977 (Sedan & Convertible)
• Volkswagen Super Beetle: 1971-1979
• Volkswagen Karmann Ghia: 1966-1974
• Volkswagen Bus (Type 2): 1963-1971 (1500cc & 1600cc models)
• Volkswagen Squareback, Fastback, Notchback (Type 3): 1966-1973
• Volkswagen Thing: 1973-1974
• Custom Applications: Sand rails, Dune Buggies, and Trikes utilizing a VW Type 1 engine case.

SPECS

• Brand: EMPI / Silverline
• Case Cut: .020 inches (0.50mm) Oversize
• Crankshaft Journal Cut: .020 inches (0.50mm) Undersize
• Thrust Flange Cut: .040 inches (1.0mm) Oversize
• Material: Steel-backed Silverline Alloy
• Engine Compatibility: 1300-1600cc Type 1, 2, and 3
• Reference Part Number: 111-198-475OS
• Quantity: Complete engine set (3 main bearings, 1 camshaft-end bearing)

PRO TIPS

Always Verify with a Micrometer

Never assume your machinist or the previous owner gave you the correct dimensions. Before installing these bearings, use a high-quality micrometer to measure your crankshaft journals and a dial bore gauge to check your case saddles. Even a .001 inch discrepancy can lead to catastrophic oil pressure loss or bearing seizure. If your case is cut .020 over and your crank is cut .020 under, these bearings will provide the perfect oil clearance, but "measuring twice and installing once" is the mantra of the master engine builder. Don''t forget to check the thrust surface of the case to ensure it matches the .040 oversize flange on this bearing set.

Cleanliness is Next to Godliness

Straight out of the box, bearings can have microscopic shipping dust or protective oils on them. Before installation, clean the bearings with a lint-free cloth and high-quality brake cleaner. More importantly, ensure the oil holes in the bearings perfectly align with the oil galleys in the engine case. If the bearing dowel pins are not seated perfectly in the bearing holes, the case halves will not torque down correctly, leading to a "crushed" bearing or a cracked case. Use a small amount of assembly lube on the bearing faces, but keep the "back" of the bearing (the side touching the case) clean and dry to ensure proper heat transfer and seating.

Setting the End-Play Correctly

Because this set features a .040 oversized thrust flange, it is specifically meant for cases where the thrust surface has been machined. After the case is torqued to spec with the crank inside, you must measure your crankshaft end-play using a dial indicator. You will adjust this end-play using three shims located behind the flywheel. Proper VW spec is generally .003 to .005 inches (.07mm to .13mm). If you have zero end-play, the engine will seize once it reaches operating temperature; if you have too much, you will hammer the thrust surface of your new bearings and potentially ruin the engine case. Always double-check your shim stack after the flywheel is torqued to its final 253 ft-lbs.