ISO 21866-1:2020

Overview

ISO 21866-1:2020 - Plain bearings - Automotive engine bearing test rig using actual connecting rods - Part 1: Test rig - specifies requirements for an engine bearing test rig that uses an actual connecting rod to assess plain bearing performance in automotive engines. The standard defines the test-rig concept and key requirements needed to evaluate fundamental bearing properties such as seizure resistance, wear resistance, fatigue resistance and resistance to the impact of foreign material. It is intended to shorten development time and reduce cost by enabling realistic, repeatable stage‑2 testing using real connecting rods before engine- or vehicle-level validation.

Key topics and technical requirements

• Test rig construction and layout: overall configuration using an actual connecting rod mounted on a driven test shaft with torque measurement, torque‑limit clutch and emergency stop provisions.
• Dynamic loading: use of a dynamic servo actuator synchronized with shaft speed and oil-hole pattern to reproduce engine-like load waveforms; load measurement via load cell.
• Lubrication and oil feed: simulated oil supply through shaft oil-holes to reproduce crankshaft lubrication conditions.
• Support bearings: guidance on support bearing types (rolling, plain, plain with cylindrical sleeve) and considerations for temperature, oil flow and clearance.
• Temperature measurement: stable thermocouple contact methods for bearing-back temperature monitoring.
• Frame, foundation and vibration control: requirement that rig-frame resonance exceeds dynamic load frequency; foundation options (edge-cutting or floating) and a foundation mass guideline (foundation weight typically 10–20× the maximum vibration load).
• Adjustability and alignment: adjustable connecting-rod joints to accommodate varying rod lengths and means to adjust misalignment between test bearing and shaft.
• Test variables: specification flexibility for waveform, amplitude, frequency, bearing geometry, lubricant viscosity and additives; multiple bearing properties may be tested concurrently.
• Informative annexes: examples for seizure and fatigue tests, oil-film calculations related to housing rigidity, and resonance-frequency calculations.

Applications and who uses it

ISO 21866-1:2020 is intended for:

• Automotive bearing manufacturers and material developers performing stage‑2 validation
• OEM engine design and test engineers validating bearing designs without full engine tests
• Independent test laboratories and quality assurance teams conducting comparative bearing testing
• Lubricant developers and tribology researchers assessing lubricant/finish interactions under realistic engine conditions

Using an actual connecting rod improves the relevance of bench tests to in‑vehicle performance, helping detect issues earlier in development.

Related standards

• ISO 4378-1 (terms and definitions for plain bearings)
• ISO 6281 (operating conditions and assessment guidance referenced)
• ISO 7146-1 and ISO 7146-2 (damage assessment methods)

Keywords: ISO 21866-1:2020, plain bearings, automotive engine bearing test rig, connecting rod, seizure resistance, wear resistance, fatigue resistance, test rig construction, support bearing, dynamic load, oil supply, vibration isolation.