ASTM WK63290

    Revision of D2699 - 17 Standard Test Method for Research Octane Number of Spark-Ignition Engine Fuel

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    Active Standard: D2699 - 19

    Developed by Subcommittee: D02.01 | Committee D02 | Contact Staff Manager



    guide table; isooctane; knock intensity; n-heptane; research octane number; spark-ignition engine fuel performance; toluene standardization fuel;;


    The current configuration of the CFR float chamber on the combination EQ/FL carburetor does not fulfill the requirement of for the bracketing dynamic equilibrium procedure for three reasons: 1. The CFR float chamber contains protrusions on the upper extremities of the reservoir and a radius at the lower extremes that reduce the cross sectional area below the specified minimum of 5.9 square inches in these areas. 2. The cross sectional area is not constant as specified. 3. The CFR carburetor contains a float mechanism with a submerged float that further reduces the effective cross sectional area of the system. In practice, the CFR reservoir functions as intended as it has in the field for many years. This can be proven with performance based historical evidence from national exchange group data submissions. Additionally, CFR has completed testing comparing the CFR float chamber to another fuel reservoir that met the original dimensional specifications of the standard which has shown that there is no detectable difference between the two for various fuels. Based on this historical and experimental data it is proposed to broaden the specification to allow for use of the current configuration of the CFR float chamber.

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    Date Initiated:

    Technical Contact:
    Robert Sinur