Cold Starting and Pumpability Studies in Modern Engines — Results from the ASTM D02.07C Low Temperature Engine Performance Task Force Activities: Phase II Pumpability Testing
Bibliographic record
Abstract
The Low Temperature Engine Performance Task Force Phase II pumpability test program focused on the evaluation of six engine oils which exhibited significant yield stress or gelation index in slow-cool bench tests. The test oils were designed specifically to have abnormal flow properties and are considered to be non-commercial formulations. The light duty engines that primarily were used included the 2.2L I-4, 3.8L V-6, 4.0L I-6 and 4.6L V-8 engine, with some additional work in the 2.3L I-4, 1.9L I-4 and 3.0L V-6. Four laboratories contributed work, and each used different engines, and often, different cooling profiles, in attempts to better establish the importance of yield stress and gelation index to air-binding failures in modern engines. For the majority of Phase II oils tested, air-binding failures were not detected. No pumping failures were detected with the phase II test oil LTEP 23, which had a gelation index of 16. Using the 4.6L V8 engine, an air-binding failure was detected only with LTEP 27, an oil that had caused air-binding failures in other work. The 2.2L I-4 engine did not fail by air-binding, but the 3.8L V-6 and 4.0L I-6 engines, which generally exhibit flow-limited failures, were “tricked” into producing air-binding failures by use of a reduced volume of test oil LTEP 28. This oil exhibited a gelation index of 40; it also exhibited a substantial yield stress (70–105 Pa) and a relatively low pumping viscosity when the engine pumping tests were run.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".