Engine Case, Aluminum, Stock Bore, For 8mm Studs

OVERVIEW

When it comes to building a foundation that lasts, the EMPI Aluminum Engine Case is the gold standard for air-cooled enthusiasts who are tired of dealing with the warped, pulled, and fatigued magnesium cases of the past. As a master specialist here at Appletree Auto, I cannot stress enough how vital a rigid crankcase is to the longevity of your Volkswagen engine. This case is cast from high-strength aluminum alloy and fully CNC machined to exacting tolerances, providing a level of structural integrity that original AS-41 or AS-21 magnesium cases simply cannot match. Whether you are rebuilding a reliable stock 1600cc for your daily driver or planning a high-performance weekend warrior, this aluminum case eliminates the common "shuffling" of the center main webs and prevents the dreaded pulled head studs that have plagued the VW community for decades. By choosing aluminum, you are investing in a component that handles heat cycles more gracefully and offers a much higher resistance to the stresses of modern driving conditions.

What truly sets this 98-0451-B engine case apart is the "Super Case" inspired design features that EMPI has integrated into the casting. It features a "bubble top" raised roof design, which provides the necessary internal volume for high-lift rockers and long-stroke crankshafts, though it remains a stock bore for standard 85.5mm, 87mm, or 88mm slip-in cylinders. We have ensured this case is "full flow" ready, meaning it is already drilled and tapped with a plug, saving you the risky and tedious shop work of doing it yourself. Furthermore, the area behind the number three cylinder has been reinforced and filled to prevent the common cracking associated with heat soak in that specific corner of the engine. With the main oil galleries already tapped for ease of cleaning and a universal dual-bypass design that accepts both early and late-style oiling systems, this is the ultimate "blank canvas" for any serious Type 1 engine build. You won''t find a more robust or versatile starting point for your air-cooled journey than this precision-engineered aluminum powerhouse.

FITMENT

This engine case is designed for Type 1, 2, and 3 air-cooled applications using 1300cc to 1600cc based internals. Note that because of the "bubble top" design, some minor trimming of the inner fan shroud is required for proper seating.

• Volkswagen Beetle: 1961-1977 (Standard and Super Beetle)
• Volkswagen Karmann Ghia: 1961-1974
• Volkswagen Bus / Type 2: 1963-1971
• Volkswagen Thing / Type 181: 1973-1974
• Volkswagen Type 3 (Squareback, Fastback, Notchback): 1962-1973 (Requires dipstick block-off or modification)
• Custom Applications: Ideal for Sand Rails, Dune Buggies, and Trikes using VW Type 1 architecture.

SPECS

• Material: High-Grade Heavy Duty Aluminum Alloy
• Bore Size: Stock (Accepts 85.5mm, 87mm, and 88mm slip-in cylinders)
• Head Stud Size: 8mm (Case includes 8mm steel inserts)
• Oil System: Universal Dual-Bypass design for superior oil pressure control
• Clearance: Bubble-top raised roof (Ready for high-lift cams/rockers)
• Oil Gallery: Drilled and tapped for Full Flow with included plug
• Main Gallery Plugs: Removable threaded plugs for easy internal cleaning
• Reinforcement: Added material behind #3 cylinder and reinforced head stud bosses
• Cam Plug: Grooved for a positive, leak-free seal
• Weight: Approximately 42-44 lbs (Significantly more mass than magnesium for added strength)
• Machining: 100% CNC Machined for precision alignment

PRO TIPS

1. The Critical "Deep Clean" Ritual

Even though this case is brand new and CNC machined, you must never assemble an engine straight out of the box. During the manufacturing and tapping process, tiny aluminum shards and "swarf" can hide inside the oil galleries. Because this case features tapped and plugged main oil galleries, you have a massive advantage. Remove all the threaded gallery plugs and use a long engine brush with a high-quality solvent to scrub every internal passage. Blow everything out with compressed air until you could literally eat off the internal surfaces. This ensures that no leftover machining debris enters your brand new bearings on the first startup, which is the leading cause of premature engine failure in new builds.

2. Master the Fan Shroud Modification

The "bubble top" design of this aluminum case is a performance upgrade that provides more internal clearance, but it makes the case slightly taller in the center than a stock magnesium unit. When fitting your doghouse fan shroud, you will notice it doesn''t sit perfectly flush against the case. Do not force the bolts or "crush" the shroud down. Instead, use a pair of aviation snips or a small grinding wheel to trim a small "U" shape or a relief notch in the bottom center of the fan shroud tins. Taking the time to get a perfect, gap-free fit here is essential for proper cooling airflow over your cylinders; if the shroud sits cocked, you will lose precious air pressure and your engine will run hotter than intended.

3. Account for Thermal Expansion

Aluminum has a different coefficient of thermal expansion than the original magnesium-alloy cases. This means that as the engine reaches operating temperature, the case expands slightly more than a stock one would. When choosing your head studs and torquing your fasteners, ensure you are using high-quality 8mm chromoly studs for the best results. Additionally, pay close attention to your deck height and bearing clearances. We recommend checking your crankshaft end-play twiceonce when dry-fitting and again after final assemblyto ensure that as the aluminum case grows with heat, your tolerances remain within the "sweet spot" for maximum oil pressure and minimum wear. Always use a high-quality assembly lube on the case halves to ensure the sealant spreads evenly without creating "high spots" that could lead to oil weeping.