deterioration factors for the combination. In the case of a significant discrepancy between data developed by the Administrator and that submitted by the manufacturer, the Administrator's data shall be used in the determination of deterioration factors.

(h) A break-in procedure, not to exceed 20 hours, may be run if approved in writing in advance by the Administrator. This procedure would be run after the 0 hour test, and the hours accumulated would not be counted as part of the service accumulation.

[37 FR 24307, Nov. 15, 1972, as amended at 38 FR 17166, June 28, 1973]

§ 85.974-8 Special test procedures.

The Administrator may, on the basis of a written application therefor by a manufacturer, prescribe test procedures, other than those set forth in this subpart, for any motor vehicle engine which he determines is not susceptible to satisfactory testing by the procedures set forth herein.

§ 85.974-9 Test procedures.

The test procedures described in this and subsequent sections will be the test program to determine the conformity of engines with the standards set forth in $ 85.974-1.

(a) The test procedure begins with a warm engine and consists of a prescribed sequence of engine operating conditions on an engine dynamometer with continuous examination of the exhaust gases.

(b) The test is designed to determine the brake-specific emissions of hydrocarbons, carbon monoxide and oxides of nitrogen when an engine is operated through a cycle which consists of three idle modes and five power modes at each of two speeds which span the typical operating range of diesel engines. The procedure requires the determination of

Item

the concentration of each pollutant, the exhaust flow and the power output during each mode. The measured values are weighted and used to calculate the grams of each pollutant emitted per brakehorsepower hour.

(c) When an engine is tested for exhaust emissions or is operated for durability testing on an engine dynamometer, the complete engine shall be tested with all standard accessories which might reasonably be expected to influence emissions to the atmosphere installed and functioning.

(d) Except in cases of component malfunction or failure, all emission control systems installed on or incorporated in a new motor vehicle engine shall be functioning during all procedures in this subpart. Maintenance to correct component malfunction or failure shall be authorized in accordance with § 85.974-6. (e) [Reserved] (f) [Reserved]

(g) All emission control systems installed on or incorporated in a new motor vehicle engine shall be functioning during all test procedures in this subpart. [37 FR 24307, Nov. 15, 1972, as amended at 38 FR 17166, June 28, 1973]

§ 85.974-10 Diesel fuel specifications.

(a) The diesel fuels employed shall be clean and bright, with pour and cloud points adequate for operability. The fuels may contain nonmetallic additives as follows: cetane improver, metal deactivator, antioxidant, dehazer, antirust, pour depressant, dye, and dispersant.

(b) Fuel meeting the following specifications, or substantially equivalent specifications approved by the Administrator, shall be used in exhaust emission testing. The grade of fuel recommended by the engine manufacturer, commerically designated as "Type 1-D" or "Type 2-D", shall be used.

97-023-7347

(c) A noninsulated exhaust system extending 15±5 feet from the exhaust manifold, or the crossover junction in the case of Vee engines, and presenting an exhaust back pressure within ±0.2 inch Hg. of the upper limit at maximum rated horsepower, as established by the engine manufacturer in his sales and service literature for vehicle application. A conventional automotive muffler of a size and type commonly used with the engine being tested shall be employed in the exhaust system during emission testing.

(d) An engine air inlet system presenting an air inlet restriction within +1 inch of water of the upper limit for the engine operating condition which results in maximum airflow, as established by the engine manufacturer in his sales and service literature, for the engine being tested.

§ 85.974-13 Sampling and

methods.

analytical

(a) The determination of the carbon monoxide and nitric oxide concentrations shall be accomplished using sampling and analysis components as specified in Sections 2.1 and 2.2 of the SAE Recommended Practice No. J177 titled, "Measurement of Carbon Dioxide, Carbon Monoxide and Oxides of Nitrogen in Diesel Exhaust," dated June 1970. Other sampling and analysis components may be used if shown to yield equivalent results and if approved in advance by the Administrator.

(b) The determination of the hydrocarbon concentrations shall be accomplished using sampling and analysis components as specified in sections 2.1 and 2.2 of SAE Recommended Practice No. J215 titled, "Continuous Hydrocarbon Analysis of Diesel Exhaust," dated November 1970.

(a) Test number.

(b) Date and time of day.
(c) Instrument operator.
(d) Engine operator.

(e) Engine identification numbersdate of manufacture-number of hours of operation accumulated on engineengine family-exhaust pipe diameterfuel injector type-low idle r.p.m., governed speed, maximum power and torque speeds-maximum horsepower and torque fuel consumption at maximum power and torque-air aspiration system-exhaust system back pressure-air inlet restriction.

(f) All pertinent instrument information such as tuning-gain-serial numbers-detector numbers-range.

(g) Recorder chart. Identify zero traces-calibration or span traces-emission concentration traces for each est mode-start and finish of each test.

(h) Ambient temperature in dynamometer testing room.

(i) Engine intake air temperature and humidity for each mode.

(j) Barometric pressure.

(k) Observed engine torque for each mode.

(1) Intake airflow or exhaust flow for each mode.

(m) Fuel flow and temperature for each mode.

§ 85.974-16 Test run.

(a) The temperature of the air supplied to the engine shall be between 68° F. and 86° F. The fuel temperature at the pump inlet shall be 100° F. +10° F. The observed barometric pressure shall be between 28.5 inches and 31 inches Hg. Higher air temperature or lower barometric pressure may be used, if desired, but no allowance shall be made for increased emissions because of such conditions.

(b) The governor and fuel system shall have been adjusted to provide engine performance at the levels specified by the engine manufacturer for maximum rated horsepower and maximum rated torque. These specifications

shall be reported in accordance with § 85.974-2(b) (3).

(c) The following steps shall be taken for each test:

(1) Install instrumentation and sample probes as required.

(2) Start cooling system.

(3) Start the engine, warm it up and precondition it by running it at rated speed and maximum horsepower for 10 minutes or until all temperatures and pressures have reached equilibrium.

(4) Determine by experimentation the maximum torque at rated speed and intermediate speed to calculate the torque values for the specified test modes. (5) Zero and span the analyzers.

(6) Start the test

emission

sequence of § 85.974-11. Operate the engine for 10 minutes in each mode, completing engine speed and load changes in the first minute. If a delay of more than 10 minutes occurs between the end of one mode and the start of the next mode, discontinue the sequence and repeat the test from Mode No. 1. Record the response of the analyzers on a strip chart recorder for the full 10 minutes with exhaust gas flowing through the analyzers at least during the last 5 minutes. Record the engine speed and load, intake air temperature and restriction, exhaust back pressure, fuel flow and air or exhaust flow during the last 5 minutes of each mode, making certain that the speed and load requirements of § 85.97411(b) are met during the last minute of each mode. Fuel flow during idle or 2 percent load conditions may be determined just prior to or immediately fol

lowing the dynamometer, sequence, if longer times are required for accurate measurements.

(7) Read and record any additional data as required for § 85.974-14.

(8) Check and reset the zero and span settings of the emission analyzers as required, but at least at the end of the second idle mode (mode No. 7) and at the end of the test. If a change of over 2 percent of full-scale response is observed, make necessary adjustments to the analyzers and repeat all test modes since the last zero and span check.

(9) Backflush condensate trap and replace filters as required.

[37 FR 24307, Nov. 15, 1972, as amended at 38 FR 17166, June 28, 1973]

§ 85.974-17 Chart reading.

(a) Locate the last 60 seconds of each mode and determine the average chart reading for HC, CO, and NO over the 1-minute period.

(b) Determine the concentration of HC, CO, NO during each mode from the average chart readings and the corresponding calibration data.

A 0.044 (F/A) -0.0038

B=0.116 (F/A) =0.0053
H=humidity of the inlet air in grains of
water per pound of dry air
T-temperature of the air in F.

F/A Fuel-air ratio (dry air basis)

(d) Calculate the mass emissions of HC (HCmass), CO (COmass), and NO. (NO mass) in grams per hour for each mode as follows:

(1) HC mass=0.0132 × HC cone X exhaust mass (lb./min.).

(2) COmass=0.0263 X CO cone X exhaust mass (lb./min.).

mass

(3) NOr, =0.0432 X NO cone X exhaust mass (lb./min.).

(e) Calculate the weighted brake horsepower and HC, CO, and NO mass values as follows:

(1) Multiply the average of the three idle values by a weighting factor of 0.2. (2) Multiply the values for all of the other modes by a weighting factor of 0.08.

(f) Calculate the brake specific emissions for HC, CO, and NOx for each set of data as follows:

(HC mass XWF)
Σ(Measured BHP XWF)

(COmassXWF)

BSHC=

BSCO=

(Measured BHP XWF)

§ 85.974-28 Compliance with emission standards.

(a) The exhaust gaseous emission standards in § 85.974-1 apply to the emissions of engines for their useful life.

(b) Since emission control efficiency decreases with the accumulation of hours on the engine, the emission level of an engine which has accumulated 1,000 hours of dynamometer operation will be used as the basis for determining compliance with the standards.

(c) The procedure for determining compliance of a new engine with exhaust emission standards is as follows:

(1) Separate emission deterioration factors shall be determined from the emission results of the durability data engines for each engine-system combination. Separate factors shall be established for CO and for the combined emissions of HC and NOx.

(i) The applicable results to be used in determining the deterioration factors for each combination shall be:

(a) All emission data from the tests required under § 85.874 (b) except the zero-hour tests. This shall include the official test results, as determined in $ 85.974-29, for all tests conducted on all durability engines of the combination selected under $ 85.874-5 (c) (including all engines selected to be operated by the manufacturer under § 85.874-5 (c) (2)).

(b) All emission data from the tests conducted before and after the maintenance provided in § 85.874-6 (a) (1) (i).

(ii) All applicable results shall be plotted as a function of the hours on the system, rounded to the nearest hour, and the best fit straight lines, fitted by the method of least squares, shall be drawn through these data points. The interpolated 125- and 1,000-hour points on this line must be within the standard provided in § 85.974-1 or the data shall not be used in calculation of a deterioration factor, unless no applicable data point exceeded the standards.

(iii) An exhaust emission deterioration factor shall be calculated for each combination as follows:

factor exhaust emissions interpolated to 1000 hours minus the exhaust emissions interpolated to 125 hours.

(2) The appropriate deterioration factor shall be added to the exhaust emissions test results for each emission data engine: Provided, That if a deterioration factor as computed in subparagraph (1) of this paragraph is negative, that deterioration factor shall be zero when comparing adjusted emissions to the standards.

(3) The emissions to compare with the standard shall be the adjusted emissions of subparagraph (2) of this paragraph for each emission data engine.

(4) Every test engine of an engine family must comply with all applicable standards, as determined in subparagraph (3) of this paragraph, before any engine in that family will be certified. [37 FR 24307, Nov. 15, 1972, as amended at 38 FR 17167, June 28, 1973]

(a) The Administrator may require that any one or more of the test engines be submitted to him, at such place or places as he may designate, for the purpose of conducting emissions tests. The Administrator may specify that he will conduct such testing at the manufacturer's facility, in which case instrumentation and equipment specified by the Administrator shall be made available by the manufacturer for test operations. Any testing conducted at a manufacturer's facility pursuant to this paragraph shall be scheduled by the manufacturer as promptly as possible.

(b) (1) Whenever the Administrator conducts a test on a test engine, the results of that test shall comprise the official data for the engine at that prescribed test point.

(2) Whenever the Administrator does not conduct a test on a test engine at a test point, the manufacturer's test data will be accepted as the official data for that test point: Provided, That if the Administrator makes a determination based on testing under paragraph (a) of this section, that there is a lack of correlation between the manufacturer's test equipment and the test equipment used by the Administrator, no manufacturer's test data will be accepted for purposes of certification until the reasons for the lack of correlation are determined and the validity of the data is established by the manufacturer.

(3) If the Administrator determines that the test data developed under paragraph (a) of this section would cause an engine to fail due to excessive 125-hour emissions or excessive deterioration, then the following procedure shall be observed:

(i) The manufacturer may request a retest. Before the retest, the engine may be adjusted to manufacturer's specifications, and parts may be replaced in accordance with § 85.974-6. All work on the engine shall be done at such location and under such conditions as the Administrator may prescribe.

(ii) The engine will be retested by the Administrator and the results of this test shall comprise the official data for that prescribed test point.

(4) If sufficient durability data is not available, at the time of any emission test conducted under paragraph (a) of this section, to enable the Administrator to determine whether a test engine would fail, the manufacturer may request a retest in accordance with the provisions of subparagraph (3) (i) and (ii) of this paragraph. If the manufacturer does not promptly make such request, he shall be deemed to have waived the right to a retest. A request for retest must be made before the manufacturer removes the engine from the test premises.