83 X 64 Piston & Cylinder Kit, Cast Pistons, 40 HP 1200cc

OVERVIEW

Rejuvenate your classic 40hp power plant with the ultimate performance upgrade that doesn''t require a trip to the machine shop. The AA Pistons 83mm x 64mm Piston and Cylinder Kit is engineered specifically for the 1200cc Volkswagen engine, providing a significant displacement boost from the stock 1192cc to approximately 1385cc. This "slip-in" big bore kit is the most cost-effective way to increase torque and horsepower while maintaining the original structural integrity of your crankcase and cylinder heads. Whether you are navigating modern traffic in a vintage Beetle or looking for that extra push in your early Transporter, this kit delivers the extra "oomph" your air-cooled VW has been craving for decades.

Manufactured by AA Performance Products, these kits feature high-quality cast pistons and durable iron cylinders designed to withstand the heat and rigors of daily driving. The kit is a complete solution, including four pistons, four cylinders, a complete set of piston rings, wrist pins, and circlips. Because this is a true slip-in kit, the cylinder skirts are machined to fit directly into the stock 40hp engine case bore, and the tops are sized to fit the factory 1200cc cylinder head registers. This eliminates the need for expensive and time-consuming engine machining, making it an ideal choice for the home mechanic or professional restorer looking to maximize the potential of the legendary 40hp platform.

FITMENT

• Volkswagen Type 1 Beetle: 1961-1965 (US Models with 40hp 1200cc engine)
• Volkswagen Type 1 Beetle: 1961-1977 (European/International 1200cc models)
• Volkswagen Type 14 Karmann Ghia: 1961-1965 (40hp models)
• Volkswagen Type 2 Bus/Transporter: 1961-1962 (40hp 1200cc models)
• Industrial Engines: Various 1200cc 40hp configurations

SPECS

• Bore Diameter: 83mm (Upgraded from stock 77mm)
• Stroke Compatibility: 64mm (Standard 40hp stroke)
• Total Displacement: 1385cc (Commonly referred to as a 1400cc kit)
• Piston Material: Hypereutectic Cast Aluminum Alloy
• Cylinder Material: Cast Iron
• Kit Includes: 4 Pistons, 4 Cylinders, Piston Rings, Wrist Pins, and Teardrop Circlips
• Compression Height: 39.10mm
• OEM Reference Number: 111-198-057ABB
• Part Number: 98-1947-B

PRO TIPS

1. Thoroughly Clean the Cylinders Before Installation

New cylinders are shipped with a heavy protective oil coating to prevent rust during transit and storage. It is absolutely critical that you wash the cylinders in hot, soapy water (dish soap works best) and scrub the bores with a nylon brush until the water runs clear. Dry them immediately and apply a very light coat of clean engine oil or assembly lube to the walls. If you fail to remove the shipping preservative, it can "glaze" the cylinder walls during the first heat cycle, preventing the piston rings from seating properly and causing chronic oil consumption.

2. Always Verify Piston Ring End Gap

Even though this kit comes with a high-quality ring set, never assume the gaps are perfect out of the box. Place each ring into its respective cylinder (use a piston to push it down about an inch to ensure it is square) and measure the gap with a feeler gauge. For a street-driven 40hp engine, you generally want to see a gap of .004 inches per inch of bore. If the gap is too tight, the ring ends can touch as they expand from heat, leading to catastrophic engine failure. Proper gapping ensures longevity and optimal compression across all four cylinders.

3. Check Your Deck Height and Compression Ratio

Increasing the bore size will naturally increase your compression ratio. When installing this 83mm kit, it is vital to measure your "deck height"the distance from the top of the piston at Top Dead Center (TDC) to the top edge of the cylinder. We recommend a minimum deck height of .040 inches to .060 inches. If the deck height is too tight, you risk the piston hitting the head at high RPM. If it is too large, your engine will lose efficiency and be prone to overheating. Use cylinder base shims if necessary to dial in the perfect clearance for your specific case and head combination.