ASTM D8350-24a PDF

Full title and description

St ASTM D8350-24a — Standard Test Method for Evaluation of Automotive Engine Oils in the Sequence IVB Spark‑Ignition Engine. This document describes the Sequence IVB engine test used to evaluate an engine oil’s ability to control valve‑train wear (bucket lifter and cam lobe wear) and overall engine wear under low‑temperature, cyclic operating conditions.

Abstract

ASTM D8350 (edition labeled 24a) is a test method that specifies the Sequence IVB procedure — a controlled, 200‑hour engine test using a Toyota 2NR‑FE 1.5 L DOHC engine with direct‑acting mechanical bucket lifters — to quantify oil performance for valve‑train protection and engine wear. Primary results include average intake lifter volume loss; secondary results include cam lobe nose wear and end‑of‑test iron concentration in the used oil. The 24a designation refers to the 2024 amendment/issue and was later succeeded by a 2025 revision (D8350‑25).

General information

• Status: Withdrawn (designation D8350‑24a; later superseded by D8350‑25).
• Publication date: Published (24a issue) in 2024 (listed as January 11, 2024 in catalog records); superseding edition published in 2025.
• Publisher: ASTM International (ASTM Committee D02 and associated subcommittees).
• ICS / categories: 75.100 — Lubricants, industrial oils and related products (engine oils; valve‑train wear testing).
• Edition / version: D8350‑24a (2024 amendment / issue); note: a subsequent edition D8350‑25 was published in 2025.
• Number of pages: Approximately 91–92 pages (catalog entries list 92 pages for the D8350 family/editions).

Scope

This test method measures the ability of crankcase oils for spark‑ignition engines to limit valve‑train wear (bucket lifter volume loss) and to assess overall engine wear at relatively low operating temperatures in an extended cyclic simulation. The procedure uses a Toyota 2NR‑FE water‑cooled, in‑line 4‑cylinder, 1.5 L engine and includes run‑time, cycle profile and post‑test measurements of lifter wear, cam lobe wear and iron concentration in the used oil. The method is intended for use in oil specification work such as API and ILSAC assessments and for comparative laboratory evaluation.

Key topics and requirements

• Test engine: Toyota 2NR‑FE, 1.5 L, DOHC, 4‑cylinder with direct‑acting mechanical bucket lifters (cam and lifters replaced prior to test setup).
• Test duration and cycle: 200 hours total runtime, composed of repeated steady and transition intervals (test cycle repeated approximately 24,000 times).
• Primary performance measure: average intake lifter volume loss (used to assess valve‑train wear).
• Secondary measures: cam lobe nose wear and end‑of‑test iron (Fe) concentration in used oil; optional determinations include fuel dilution, non‑ferrous wear metals, oil and fuel consumption.
• Typical acceptance/limits (used in specifications): example reference limits associated with Sequence IVB for some specifications (e.g., average intake lifter volume loss ≤ 2.7 mm³ and End‑of‑Test Fe ≤ 400 ppm in some API/ILSAC/JASO contexts); check the applicable specification for required pass/fail criteria.
• Use in specifications: method is referenced for oil classifications and engine oil specifications (for example API SP, ILSAC GF‑6A/GF‑6B and related regional specifications where applicable).

Typical use and users

Primary users are lubricant formulators, engine manufacturers, oil test laboratories, quality and specification engineers, and certification bodies who need a laboratory method to evaluate valve‑train protection and general engine wear performance for modern spark‑ignition engine oils. Regulatory or standards bodies and R&D organizations also use the test for comparative evaluations and to support oil specifications.

Related standards

Standards and specifications that commonly reference or use Sequence IVB results include oil industry performance specifications such as API SP and ILSAC GF‑6A/GF‑6B and regional standards that address valve‑train wear testing (for example JASO limits where applicable). Sequence IVB is one of the Sequence/engine test family methods used to assess different wear and performance attributes of engine oils.

Keywords

Sequence IVB, engine oil test, valve‑train wear, cam lobe wear, bucket lifter volume loss, Toyota 2NR‑FE, engine wear, iron concentration, ASTM D8350, lubricants, crankcase oils.

FAQ

Q: What is this standard?

A: ASTM D8350‑24a is a test method (Sequence IVB) for evaluating automotive engine oils in a specified Toyota 2NR‑FE spark‑ignition engine to assess valve‑train and engine wear under cyclic, low‑temperature conditions.

Q: What does it cover?

A: It covers the test setup, engine preparation, run cycle, sampling and post‑test measurements — principally average intake lifter volume loss, cam lobe wear, and end‑of‑test iron concentration — plus related test‑operation and reporting requirements.

Q: Who typically uses it?

A: Lubricant developers and formulators, independent test laboratories, engine makers, specification authors (API/ILSAC/JASO), and certification bodies use this method for product development, quality control and specification compliance testing.

Q: Is it current or superseded?

A: The 24a issue (2024) is listed in catalog records as withdrawn/superseded; a later revision, ASTM D8350‑25, was published in 2025 and is the active edition for the method family. Users should reference the active ASTM title/edition required by their specification or certifying authority.

Q: Is it part of a series?

A: Yes — Sequence IVB is part of the family of engine sequence tests used for engine oil evaluation; ASTM maintains the D8350 method (and updates/editions) under Committee D02 with information letters and periodic revisions.

Q: What are the key keywords?

A: Sequence IVB, engine oil test, cam lobe wear, bucket lifter volume loss, iron (Fe) concentration, valve‑train wear, Toyota 2NR‑FE, ASTM D8350.