Piston Ring Set, 94mm, 1.5 X 2 x 4, for Aircooled VW

OVERVIEW

When you''re building a high-performance air-cooled engine, the piston rings are the unsung heroes that bridge the gap between explosive power and catastrophic failure. This Grant Piston Ring Set, specifically designed for 94mm bore applications, offers the precision engineering required to maintain a perfect seal under the intense thermal loads common in larger displacement Volkswagen engines. Whether you''re assembling a punchy 1914cc street motor or a high-revving 2332cc monster, these rings provide the critical compression seal needed to maximize horsepower while ensuring that oil stays in the crankcase where it belongs. Grant has been a staple in the VW industry for decades, known for producing rings that seat quickly and provide long-lasting durability even in the harsh, air-cooled environment of a Beetle, Bus, or high-performance sand rail.

These rings feature the standard 1.5mm top, 2.0mm second, and 4.0mm oil scraper configuration, making them the primary choice for the vast majority of aftermarket 94mm piston and cylinder kits, including those from Mahle and AA Performance. The top compression ring is engineered to handle the primary combustion pressure and heat, while the second ring acts as a scraper to assist in oil control and provide a secondary pressure barrier. The 4.0mm oil control ring is a sophisticated multi-piece design that ensures a consistent, microscopic film of oil on the cylinder walls without allowing excess lubricant to enter the combustion chamber. By choosing a high-quality set like the G1995, you are investing in the longevity of your engine, significantly reducing blow-by, and maintaining higher vacuum levels, which is essential for any vintage VW that sees regular spirited driving or off-road abuse.

FITMENT

• Volkswagen Type 1: Beetle and Bug (1950-1979) with 94mm Big Bore Kits.
• Volkswagen Type 2: Bus, Transporter, and Kombi (1950-1971) with 94mm Big Bore Kits.
• Volkswagen Type 3: Fastback, Squareback, and Notchback with 94mm Big Bore Kits.
• Volkswagen Karmann Ghia: (1955-1974) equipped with upgraded 94mm bore engines.
• Volkswagen Type 181 Thing: (1973-1974) with performance engine upgrades.
• Custom Applications: Ideal for Meyers Manx, Sand Rails, Dune Buggies, and Trikes utilizing Type 1 based air-cooled engines.
• Engine Sizes: Common in 1914cc, 2017cc, 2110cc, 2165cc, 2276cc, and 2332cc configurations.

TECHNICAL SPECIFICATIONS

• Bore Size: 94mm (Standard for VW Big Bore applications).
• Top Compression Ring Thickness: 1.5mm.
• Second Compression/Scraper Ring Thickness: 2.0mm.
• Oil Scraper Ring Thickness: 4.0mm (Three-piece design).
• Material: High-grade cast iron and steel alloy for superior heat dissipation.
• Quantity: Complete set for 4 pistons (enough for one complete VW flat-four engine).
• OEM Cross Reference: 311-198-16994.
• Manufacturer Part Number: G1995 (Grant Piston Rings).
• Compatibility: Fits most AA, Mahle, and Cima 94mm piston sets.

PRO TIPS FROM THE SHOP

1. NEVER SKIP THE RING GAP CHECK

Even though these are high-quality Grant rings, you must "end-gap" every single ring for its specific cylinder. Air-cooled engines run significantly hotter than water-cooled engines, causing the rings to expand more. If your ring gap is too tight, the ends will touch as the engine reaches operating temperature, leading to a broken ring land or a seized piston. Place each ring into the cylinder about an inch down, use the piston to square it up, and check the gap with a feeler gauge. For a street-driven 94mm engine, we typically look for a gap of approximately .015 to .017 inches on the top ring. Always consult your engine builder''s specifications for your specific compression ratio and usage.

2. PROPER CYLINDER WALL PREPARATION

If you are installing these rings on a used set of cylinders, you must deglaze the walls first. A "mirror" finish on the cylinder walls will prevent the new rings from seating correctly, leading to oil consumption and poor compression. Use a 240-grit ball hone or a standard three-finger hone with light oil to create a distinct 45-degree cross-hatch pattern. This texture allows the new rings to wear in slightly against the wall, creating a perfect mechanical seal. After honing, clean the cylinders with hot soapy water until a white paper towel wiped inside comes out perfectly clean; any leftover grit will act like sandpaper on your new rings.

3. RING ORIENTATION AND LUBRICATION

When installing the rings onto the piston, pay close attention to the markings. Most top and second rings will have a "Top" mark or a small dot near the gap; this MUST face the combustion chamber. Furthermore, you must stagger the ring gaps. Never line the gaps up in a row, as this creates a direct path for combustion gases to escape into the crankcase (blow-by). We recommend a 120-degree stagger, ensuring no gap is aligned with the piston pin bore or the thrust side of the piston. Use a light coating of assembly lube or clean engine oil on the rings and a high-quality ring compressor to ensure they slide into the cylinder without snapping.