SL36006W-A20P - Superior Air Parts Millennium Cylinder Assembly

SL36006W-A20P – Superior Air Parts Millennium FAA-PMA Cylinder Assembly for Lycoming 360-Series

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The Superior Air Parts SL36006W-A20P is a premium, FAA-PMA certified Millennium® series complete cylinder assembly, engineered as a direct, enhanced replacement for cylinders on specific models of Lycoming's wide-deck, 360-series engines. Backed by one of the most respected names in the piston engine aftermarket, this assembly is the result of decades of research and development, focusing on improving the durability, thermal efficiency, and service life of the original Lycoming design. As an FAA-PMA part, it has been rigorously tested and certified to be an airworthy component that is equal to or superior than the part it is designed to replace.

This unit is delivered as a complete "power assembly," including a factory-installed valve train and a matched piston kit. It is designed for mechanics and engine builders who demand advanced engineering, superior materials, and a proven track record of reliability. The Millennium cylinder's design addresses common failure modes of older cylinders, incorporating enhancements to the barrel, head casting, and cooling fins to create a more robust and longer-lasting component.

Key Features

• FAA-PMA Approved: Fully certified by the FAA as a safe and airworthy replacement for the original Lycoming cylinder on a range of O-360 engines.

• Through-Hardened Steel Barrel: The proprietary aerospace steel alloy barrel is through-hardened, providing a deep, uniform hardness that allows the cylinder to be rebored to service limits multiple times. This dramatically increases the component's operational life compared to single-run, case-hardened barrels.

• Enhanced Cooling Fin Design: Features an optimized fin geometry with increased surface area, improving convective heat transfer and promoting lower cylinder head temperatures, which reduces stress and the risk of detonation.

• High-Integrity Aluminum Head: The cylinder head is cast from a high-strength aluminum alloy and features reinforced critical areas and a robust, rolled-thread head-to-barrel interface for maximum structural integrity.

• Ready-to-Install Assembly: Arrives complete with factory-installed valves, bronze valve guides, springs, and a matched piston kit, reducing labor time and ensuring a perfect component match for a reliable overhaul.

Technical Specifications

• Part Number: SL36006W-A20P

• Component Type: FAA-PMA Complete Cylinder Assembly

• Manufacturer: Superior Air Parts, Inc.

• Engine Applicability: Lycoming 360-series, wide-deck, parallel-valve engines with low-compression pistons (e.g., 7.2:1 ratio).

• Barrel Material & Process: Through-Hardened Aerospace Steel Alloy.

• Head Material & Process: High-Strength Aluminum Alloy Casting.

• Piston: Included, configured for a 7.2:1 (or as specified) compression ratio.

• Kit Contents (Typical):

  • Complete Cylinder Assembly (pre-assembled with valves, springs, etc.)

  • Piston and Piston Ring Set

  • Piston Pin and Pin Plugs

  • Rocker Cover Gaskets, Cylinder Base O-Ring, Intake and Exhaust Gaskets.

Parts in this Assembly

Eligibilities

Engine Compatibility

The SL36006W-A20P assembly is FAA-PMA approved for specific Lycoming O-360 series, wide-deck, parallel-valve engine models. Common applicable engine models include, but are not limited to:

• O-360: -A2D, -A2F, -A2G, -A2H, -A3D, -A4G, -A4J, -A4K, -A4M, -F1A6

Crucial Note: This list is for reference only. The official Superior Air Parts application guide and the FAA-PMA supplement for this part are the final authorities for verifying installation eligibility on a specific engine model and serial number.

Applications

The SL36006W-A20P assembly is intended for engine overhaul, repair, and upgrade. Primary uses include:

• Engine Top Overhaul: The ideal choice for a complete power section rebuild, incorporating modern design enhancements.

• Single Cylinder Replacement: Used to replace an individual cylinder deemed unserviceable due to low compression, cracking, or damage.

• Durability Upgrade: Replaces original case-hardened cylinders with a superior, multi-life through-hardened design.

Why Choose SL36006W-A20P?

Choosing the Superior Air Parts Millennium cylinder is a decision for long-term value and engineered reliability. The through-hardened barrel's ability to be repeatedly overhauled provides a significant reduction in lifecycle cost compared to single-use alternatives. Superior's design enhancements in cooling and structural integrity are based on decades of in-service field data, directly addressing the known weak points of older cylinder designs. Backed by Superior's reputation and one of the most comprehensive PMA approvals in the industry, the SL36006W-A20P provides peace of mind and a tangible upgrade to your Lycoming engine.

The engineering philosophy behind the Millennium cylinder's enhanced thermal performance is rooted in fundamental heat transfer principles. The rate of convective heat transfer (q) from the cylinder to the cooling air is governed by Newton's Law of Cooling: q=hA(Ts​−T∞​). In this equation, 'A' represents the total surface area of the component exposed to the cooling medium. The Millennium cylinder head casting features a significantly increased number of thinner, aerodynamically shaped cooling fins compared to some legacy designs. This increase in fin density directly increases the total surface area ('A'), allowing the cylinder to reject more waste heat to the atmosphere for a given cylinder head surface temperature (Ts​). By more efficiently managing thermal loads, the cylinder maintains lower operating temperatures in critical areas, such as around the exhaust valve seat and the head-to-barrel interface. This superior thermal management reduces the risk of thermally induced stress cracking, improves detonation margins, and contributes to a longer, more reliable service life for the entire power assembly.

Note: This is a flight-critical engine component. The installation of this cylinder assembly constitutes a major engine repair and must be performed by a certified A&P/IA mechanic. All procedures must be conducted in strict accordance with Superior Air Parts installation instructions and the applicable Lycoming overhaul manual. Proper engine break-in procedures are mandatory after installation to ensure correct seating of the piston rings and to validate the manufacturer's warranty.

Documentation

The official FAA-PMA Approved Replacement Part Master List (Supplement) and the Superior Air Parts application data contain the definitive list of engine models this cylinder is eligible for installation on. All installation and maintenance procedures must reference the applicable Lycoming overhaul manual and Superior's installation instructions.