Rod Bearing, .020 Under, for Type 1 VW Kolbenschmidt

OVERVIEW

When it comes to the heart of your air-cooled engine, precision isn''t just a goalit''s a requirement for survival. These Kolbenschmidt Rod Bearings, specifically engineered for a .020 undersize (0.50mm) crankshaft grind, represent the gold standard in engine restoration components. As any seasoned VW builder knows, the connecting rod bearings bear the brunt of the combustion force, translating linear piston motion into the rotational energy that drives your Beetle or Bus down the road. Utilizing Kolbenschmidt bearings ensures that you are installing a product with a pedigree of German engineering excellence, providing the exact clearances necessary to maintain oil pressure and reduce friction-induced heat. Whether you are reviving a high-mileage daily driver or assembling a weekend cruiser, these bearings provide the structural integrity needed to protect your crankshaft from premature wear and catastrophic failure.

Choosing the .020 undersize set is a critical decision typically made after a professional machine shop has inspected your crankshaft journals and determined that a standard polish won''t suffice. By grinding the journals down by .020 inches, the machinist removes scoring, heat spots, and out-of-round conditions, effectively "truing" the crank to like-new geometry. These Kolbenschmidt bearings are manufactured with a multi-layer metallic composition designed to embed small particles and resist the high-revving stresses of the Type 1 engine platform. At Appletree Automotive, we understand that "good enough" never is when it involves your rotating assembly. That is why we stock these genuine Kolbenschmidt sets; they offer the consistent wall thickness and crush fit that air-cooled enthusiasts have relied on for decades to achieve 100,000-mile reliability and beyond.

FITMENT

• Volkswagen Type 1: Beetle and Super Beetle (1954-1979)
• Volkswagen Type 2: Transporter, Bus, Kombi, and Microbus (1954-1971)
• Volkswagen Type 3: Fastback, Squareback, and Notchback (1961-1973)
• Volkswagen Karmann Ghia: All years (1955-1974)
• Volkswagen Thing: Type 181 (1973-1974)
• Engine Displacements: 1200cc, 1300cc, 1500cc, and 1600cc based upright engines.
• Custom Builds: Dune Buggies, Sand Rails, and Trikes utilizing VW Type 1 engine cases.

SPECS

• Manufacturer: Kolbenschmidt (Original Equipment Quality)
• Part Number: 113-105-713
• Size Specification: .020 Under (0.50mm Undersize)
• Application: Connecting Rod Journals
• Quantity: Complete set of 8 shells (Service for 4 Connecting Rods)
• Material: High-strength steel backing with premium bearing alloy lining
• Compatibility: Fits standard VW Type 1 connecting rods
• Design: Precision-stamped with locating tangs for secure positioning

PRO TIPS

1. Always Verify with a Micrometer

Never assume your crankshaft size based on what was previously installed or a verbal note from a previous owner. Before opening your bearing packaging, use a high-quality micrometer to measure your rod journals at multiple points (top, bottom, and sides) to check for taper and out-of-roundness. A .020 undersize bearing is designed for a journal that has been ground specifically to that dimension. If your measurements are off by even a few thousandths, you risk either "seizing" the engine due to lack of clearance or suffering from "low oil pressure" if the clearance is too wide. Double-check your machinist''s work every single time to ensure the oil film gap is within the factory specification of .001 to .002 inches.

2. Absolute Cleanliness is Mandatory

The smallest speck of dust or a single metal shaving behind the bearing shell can create a "high spot," leading to localized friction and immediate bearing failure upon startup. When installing these Kolbenschmidt bearings, clean the connecting rod bores and the back of the bearing shells with a lint-free cloth and a bit of brake cleaner or solvent. Do not get oil on the backside of the bearing; you want a "dry" fit between the shell and the rod to ensure the bearing doesn''t spin. Only apply high-quality assembly lube to the "face" of the bearing where it contacts the crankshaft journal. This ensures protection during those first critical seconds of the initial start-up before the oil pump has fully pressurized the system.

3. Proper Rod Orientation and Torque Sequence

When installing your rods onto the crank with these new bearings, pay close attention to the orientation marks on the rods. In a standard VW Type 1 engine, the "tangs" (the notches that hold the bearings in place) usually face downward or toward the camshaft, depending on your specific rod brand. Mixing up the rod caps or installing a rod backward can lead to a binding rotating assembly. Once positioned, use a calibrated torque wrench to bring your rod bolts to the factory specification (usually 24-25 ft-lbs for stock 8mm bolts). After torquing each rod, rotate the crankshaft by hand. It should spin freely without any tight spots. If you feel resistance, stop immediately and investigate the clearance before proceeding with the rest of the long-block assembly.