CO-300 - Tempest FAA-PMA Oil Filter Adapter for Continental Engines

CO-300 – Tempest FAA-PMA Oil Filter Adapter 🛠️

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Overview

The Tempest CO-300 Oil Filter Adapter is a highly popular, Supplemental Type Certificate (STC) and FAA-PMA (Parts Manufacturer Approval) approved aftermarket modification designed to upgrade specific Continental reciprocating engines from the original oil screen assembly to a modern, high-efficiency spin-on oil filter system. This engine-mounted adapter replaces the engine's original oil screen cap and screen housing, providing the necessary manifold and threading to utilize a full-flow, disposable, automotive-style oil filter (such as the Tempest AA48108-2).1

The primary function of the CO-300 is to dramatically enhance engine oil filtration effectiveness. Unlike the original equipment oil screen, which primarily captures large debris, the spin-on filter provides superior filtration, removing fine particles that contribute significantly to bearing wear, cam and lifter spalling, and overall accelerated engine degradation. This conversion is a crucial preventative maintenance modification that extends engine life, simplifies the oil change process, and often provides a measurable increase in time between oil changes (TBO), subject to adherence to the specific engine maintenance manual and airframe instructions.2

Key Features

• Superior Filtration Upgrade: Converts the engine from a basic debris-catching oil screen to a full-flow, high-micron-rating spin-on filter cartridge.3

• Engine-Mounted, No External Hoses: The adapter installs directly into the oil screen housing, eliminating the complexity, weight, and potential leak points associated with remote-mounted filter systems.4

• Oil Temperature Probe Relocation: Includes a design feature that relocates the oil temperature probe from the original oil screen location into the end of the adapter's spool/transfer cylinder.

• Torque-Plate Design: Composed of a sleeve (CO-300-2) and a spool (CO-300-3) designed to securely anchor the adapter to the accessory case, ensuring positive sealing and alignment.

• STC and FAA-PMA Approved: Certified for installation, guaranteeing compliance with FAA airworthiness standards and eliminating the need for Field Approval (Form 337).

Technical Specifications

• Part Number: CO-300 (Kit)

• Component Type: Engine-Mounted Oil Filter Adapter5

• Manufacturer: Tempest (Stratus Tool Technologies, LLC / Aero Accessories, LLC)6

• Approval Status: FAA-PMA and STC SE8409SW Approved.7

• Engine Applicability: Continental C-125 Series, C-145 Series, and O-300 Series reciprocating engines.8

• Filter Threading: Standard threading compatible with common spin-on aviation oil filters (e.g., Tempest AA48108-2, Champion CH48108, or equivalent).9

• Adapter Components: Kit includes Adapter Sleeve (CO-300-2), Oil Transfer Cylinder/Spool (CO-300-3), Copper Gaskets (AN900-28), Lower Gasket (ST07, or copper), and a new oil filter.

• Installation Torque: The oil transfer cylinder must be torqued to 65 foot-pounds (ft. lbs.)—mandatory per the Instructions for Continued Airworthiness (ICA).

• Safety Critical Requirement: Requires mandatory safety wiring of the transfer cylinder to the engine accessory case.

• Airworthiness Directive (AD): Subject to AD 2022-04-04, which mandates the replacement of the original fiber gasket with a copper gasket to prevent oil starvation issues.10 The current Tempest kits comply with this requirement.

Aircraft Compatibility

• Primary Airframe Models:

  • Cessna 17011

  • Cessna 172 (Original models with applicable engines)12

  • Globe Swift

  • Beechcraft Bonanza (Early models with applicable engines)

  • Maule Aircraft13

• Engine Series: Continental C-125, C-145, and O-300 (O-300-A, B, C, D) engines.14

• Verification Note: The aircraft's Illustrated Parts Catalog (IPC) and the STC SE8409SW Approved Model List (AML) are the final authorities for part applicability.

Applications Section

The CO-300 is specifically a Maintenance and Performance Upgrade applied to:

• Primary Engine Lubrication System: Integration point for the high-efficiency filtration medium directly into the main oil flow circuit.

• Oil Maintenance Simplification: Facilitates easier, less messy, and more frequent oil filter changes compared to the time-consuming removal and cleaning of a traditional oil screen.15

• Engine Longevity: Proactively reduces component wear by limiting the circulation of combustion byproducts and abrasive metallic particles, particularly on older Continental engine designs.16

Why Choose the CO-300 FAA-PMA Oil Filter Adapter?

The Tempest CO-300 is the industry standard for upgrading legacy Continental engines. The choice of a certified FAA-PMA/STC adapter, as opposed to an uncertified field modification, is critical for airworthiness compliance and safety. Oil filter adapter integrity is a high-risk area, evidenced by the issuance of multiple Airworthiness Directives (ADs) related to similar adapters. The CO-300, particularly in its latest revision, addresses known concerns by mandating a high installation torque of 65 ft. lbs. and requiring safety-wire retention. Using this certified part ensures that the materials (e.g., the machining tolerance and thermal stability of the metal casting) are appropriate for the extreme thermal and vibrational environment of a high-power reciprocating engine, minimizing the risk of a catastrophic oil system failure and subsequent engine stoppage.

The fundamental engineering principle behind the CO-300 upgrade is the transition from Nominal Filtration (using a simple screen) to Absolute Filtration (using a pleated media cartridge). In a reciprocating engine, maintaining the hydrodynamic film in the plain bearings requires the rapid removal of fine abrasive particles (typically $<10$ microns) which are too small for the original screen to capture. These particles are often combustion soot or nascent metallic wear debris. The CO-300 allows the use of filters with an engineered media (e.g., cellulose or synthetic fiber) that establishes a controlled pore size distribution. The spool component (CO-300-3) is critical; it is a precisely machined tube and flange assembly that acts as a transfer cylinder, directing the oil flow from the accessory case ports through the central tube into the filter medium and returning the filtered oil back into the lubrication circuit. The secure 65 ft. lbs. torque requirement is necessary to achieve the specific compressive preload on the crush gaskets, ensuring a high-pressure seal that prevents oil loss due to engine vibration and thermal expansion differentials.

Note: The Tempest CO-300 is a maintenance-critical modification requiring strict adherence to the STC Installation Instructions (Tempest DN ST006, latest revision). The mandatory 65 ft. lbs. torque for the spool and the subsequent safety-wiring are non-negotiable flight safety items. Furthermore, the transfer cylinder must be re-torqued between 8 and 12 hours of initial operation after installation, or anytime the adapter is removed and reinstalled, to mitigate the risk of separation (a condition addressed by previous ADs). Installation must be performed and certified by a licensed A&P mechanic in accordance with the installation manual and all applicable FAA regulatory guidance.

Documentation

Authoritative documentation for this FAA-PMA/STC part is available from the manufacturer and the FAA:

• Tempest CO-300 Installation Instructions (DN ST006): Consult the latest revision from the manufacturer's website for torque, safety wire, and gasket requirements.

• FAA Supplemental Type Certificate (STC) SE8409SW: The legal basis for the modification and the Approved Model List (AML) for engine/aircraft compatibility.

• Airworthiness Directive (AD) 2022-04-04: Mandates the use of a copper gasket in place of the fiber gasket for affected adapters, which current Tempest kits incorporate.22