An Induction System Deposit Technique for Motor Gasolines — Procedure and Utilization

The tendency of motor gasolines to form deposits on the intake valve and port surfaces of spark-ignition engines can be evaluated by a bench apparatus developed for the U.S. Army. The apparatus consists of a carbureted fuel-air system which sprays the test fluid on a heated deposit collecting tube at a 2.0 ml/minute rate. Combat gasoline (MIL-G-3056C), commercial (or VV-G-76) gasolines, and special solvents can be evaluated, using a sample volume of 150 ml. The results obtained by this technique have been correlated with data obtained during a military vehicle fleet test. The procedure has also been used to study effects of gasoline additives, storage conditions, and storage duration on fuel degradation, and as an aid in the development of deterioration predictive tests. The results of a round-robin tests for reproducibility initiated at Army petroleum testing laboratories within the United States, are provided.