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

OVERVIEW

When you are building a high-performance air-cooled engine, the interface between your pistons and cylinder walls is where the magic happens. This Grant 94mm Piston Ring Set is engineered specifically for the most popular "big bore" displacement configurations in the Volkswagen world, including the 1914cc, 2110cc, 2180cc, and the legendary 2276cc powerhouses. These aren''t just off-the-shelf rings; they are designed to handle the extreme thermal expansion and high-heat environments inherent to the air-cooled flat-four design. By utilizing a 2mm top ring, a 2mm second ring, and a 4mm oil scraper, this set provides the structural integrity needed to maintain a perfect seal under high-compression loads while ensuring that oil stays in the crankcase and out of your combustion chamber. Whether you are refreshing a tired street engine or assembling a fresh long block for your weekend cruiser, these rings offer the reliability and precision that Grant has been known for in the automotive industry for decades.

The secret to a long-lasting VW engine lies in its ability to maintain consistent compression across all four cylinders, and that starts with the quality of your piston rings. This set is manufactured to exacting tolerances to ensure that blow-by is minimized, which not only preserves your horsepower but also keeps your engine oil cleaner for longer periods. The 94mm bore size is the gold standard for enthusiasts looking to maximize displacement without sacrificing too much cylinder wall thickness, making it the go-to choice for both naturally aspirated and mild turbo applications. These rings are compatible with most major piston brands used in the VW industry, such as Mahle and AA Performance, providing a versatile solution for your engine rebuild. When you install these rings, you are investing in the "breathability" and efficiency of your Volkswagen, ensuring that every stroke of the piston translates into maximum torque at the wheels.

FITMENT

This 94mm Piston Ring Set is designed for use with aftermarket 94mm piston and cylinder kits. While 94mm was not an original factory size, it is used extensively in high-performance builds for the following models (assuming the case and heads have been machined for 94mm bore):

• Volkswagen Type 1: Beetle, Bug, and Super Beetle (Custom 1914cc+ builds).
• Volkswagen Type 2: Bus, Transporter, Kombi, and Westfalia (Performance upgrades).
• Volkswagen Type 3: Fastback, Squareback, and Notchback.
• Volkswagen Karmann Ghia: All years with upgraded performance engines.
• Volkswagen Thing: Type 181 models with oversized engines.
• Off-Road: Sand Rails, Dune Buggies, and Baja Bugs utilizing Type 1 or Type 3 engine cases.

SPECS

• Bore Diameter: 94mm (Standard for high-performance VW "Big Bore" kits).
• Top Compression Ring Thickness: 2.0mm.
• Second Compression Ring Thickness: 2.0mm.
• Oil Control Ring Thickness: 4.0mm (3-piece design for superior oil scraping).
• Material: Premium high-tensile cast iron and steel construction.
• Configuration: Set for four (4) pistons (Complete engine set).
• Manufacturer: Grant Piston Rings.
• Part Number Reference: G1993 / 311-198-16995.

PRO TIPS

1. Always Check Your End Gap

Never install piston rings straight out of the box without checking the ring end gap inside the actual cylinder they will be living in. For an air-cooled VW, the heat causes significant expansion. Use a feeler gauge to measure the gap; a general rule of thumb for a street-performance 94mm engine is approximately .004 inches of gap per inch of bore diameter. If the gap is too tight, the ends of the rings can touch as the engine reaches operating temperature, which will lead to broken piston lands or a seized engine. Take your time to file-fit them if necessary to ensure a safe, reliable clearance.

2. Master the "Clocking" Sequence

Proper ring orientation, often called "clocking," is vital to prevent compression loss and oil consumption. You must stagger the gaps of the rings so they do not align. A common practice is to position the top ring gap at 12 o''clock, the second ring gap at 6 o''clock, and the oil scraper expander and rails at the 2 o''clock and 10 o''clock positions. This creates a "labyrinth" seal that makes it much harder for combustion gases to find a direct path into the crankcase. Always double-check your positioning right before you slide the cylinder over the piston.

3. Proper Cylinder Preparation is Key

If you are installing these new rings into used 94mm cylinders, you must deglaze the cylinder walls first. Use a flex-hone (dingleberry hone) or a brush hone with a light lubricant to create a fresh cross-hatch pattern at a 45-degree angle. This microscopic texture is what allows the new rings to "seat" properly by wearing in against the wall during the first few minutes of engine operation. Without this cross-hatch, the rings may never seat, leading to permanent oil burning and "blue smoke" out of your exhaust. Clean the cylinders thoroughly with hot soapy water after honing until a white cloth comes out spotless.