Crankshaft, 78mm, Forged Chromoly, 8 Dowel, Chevy Journals

OVERVIEW

When you''re building a high-performance air-cooled Volkswagen engine, the crankshaft is the literal heartbeat of your machine. This EMPI 78mm Forged 4340 Chromoly Crankshaft is engineered specifically for the enthusiast who demands more than just a standard replacement. By increasing the stroke to 78mm, you are significantly boosting your engine''s displacement and torque potential, providing that low-end grunt and high-RPM reliability that every racer or performance street driver craves. Forged from high-tensile 4340 chromoly steel, this crank undergoes a rigorous manufacturing process including magnafluxing to ensure there are no hidden flaws and shot-peening to enhance fatigue resistance. The result is a rotating assembly component that can withstand the extreme stresses of high-compression ratios and aggressive driving without breaking a sweat.

Precision is the name of the game with the EMPI stroker series. This crankshaft features Chevy journals, which are smaller than standard VW journals (2.000 inches), allowing for increased clearance inside the case and the use of widely available high-performance Chevy-style connecting rods. Every journal is micro-polished and nitrided for a glass-smooth finish and incredible surface hardness, reducing friction and extending the life of your bearings. The oil holes are cross-drilled and chamfered to ensure optimal lubrication to the rod journals even under the most demanding centrifugal forces. Additionally, the 8-dowel configuration provides a rock-solid interface between the crank and the flywheel, preventing the dreaded shearing of dowel pins that often plagues high-horsepower builds. Balanced dynamically to racing specifications, this crankshaft is ready to be the foundational anchor of your next powerhouse Type 1 build.

FITMENT

This 78mm stroker crankshaft is designed for Type 1 based engine cases. Please note that stroker crankshafts require internal case clearancing and the use of specific high-performance components. It is compatible with the following models:

• Volkswagen Beetle: 1954-1977 (Sedan & Convertible)
• Volkswagen Karmann Ghia: 1956-1974
• Volkswagen Bus / Transporter: 1954-1971 (Type 2 with Type 1 based engine)
• Volkswagen Type 3: 1961-1973 (Squareback, Fastback, Notchback)
• Volkswagen Thing: 1973-1974
• Custom Applications: Sandrails, Dune Buggies, and Trikes utilizing a VW Type 1 engine case.

SPECS

• Material: Forged 4340 Chromoly Steel
• Stroke: 78mm (Stroker)
• Journal Type: Chevy 2.000'' Journals
• Dowel Pattern: 8-Dowel (Standard VW Pattern)
• Oil Holes: Cross-drilled and Chamfered for superior lubrication
• Surface Treatment: Nitrided Journals and Shot-peened for fatigue resistance
• Inspection: Magnafluxed to ensure structural integrity
• Finish: Micro-polished bearing surfaces
• Pins: Includes extra-long dowel pins
• Balancing: Dynamically balanced
• Weight: Approximately 24.6 lbs

PRO TIPS

1. Master the Case Clearance Process

Installing a 78mm stroker crank isn''t a "drop-in" affair; you must clearance the engine case to allow the connecting rods to rotate without hitting the case webbing or the camshaft. We highly recommend a "dry fit" assembly where you install the crank and rods into the case halves without sealant. Rotate the assembly slowly and use a paint pen or marker to identify where the rod bolts or big ends come close to the case. You should aim for a minimum of .060'' clearance. Using the Chevy journals on this crank makes this easier because the smaller rod ends require less material removal compared to standard VW journals.

2. Optimize Your Rod Choice

Because this crankshaft utilizes 2.000'' Chevy journals, you must use connecting rods designed for this specific size. This is actually a major advantage for high-displacement engines. Chevy-journal rods are typically narrower and have a smaller overall diameter than stock VW rods. This reduced "swing" profile allows you to run a longer stroke like this 78mm while removing less metal from your case and camshaft, maintaining better structural integrity in your engine block while still achieving the displacement gains you''re looking for.

3. Precision End Play and Torque

With an 8-dowel high-performance crankshaft, your flywheel connection is significantly stronger, but it still requires precision setup. Always measure your crankshaft end play using a dial indicator after the flywheel is installed with the metal gasket and shims. Your target should be between .003'' and .005''. When you''re ready for final assembly, use a high-quality chromoly gland nut and torque it to at least 275-350 ft-lbs (check your specific gland nut manufacturer''s specs). A loose flywheel will ruin the 8-dowel holes and the crank, so don''t skip the heavy-duty torque wrench!