fuel shall be achieved over a period of 60 minutes 10 minutes using a constant rate of heat input. After a minimum of 1 hour, following admittance to the 76° F.-86° F. soak area, the vehicle will be moved onto the dynamometer stand for the subsequent part of the test. The fuel tank thermocouple may be temporarily disconnected to permit moving the test vehicle. Plugs will be removed from the exhaust pipe(s) and inlet pipe to the air cleaner.

(b) Running loss test. (1) The test vehicle will be placed on the dynamometer with the hood up and the cooling fan positioned between 8" and 12'' from the grill and directed squarely at the radiator. (Exception: air cooled engines). The ambient air temperature will be maintained between 68° F.-86° F. and recorded, together with the fuel temperature, at a chart speed of approximately 12 inches per hour (or equivalent record).

(2) Where the only external vent(s) is located in the immediate vicinity of the carburetor air horn, such that any “running loss" emissions would be inducted into the engine, there is no requirement to collect any vapor losses during this part of the test and the vapor-loss measurement system will be temporarily disconnected and clamped.

(3) The vehicle will be operated on the dynamometer according to the requirements and procedures of §§ 85.75-85.85. The engine and fan will be turned off upon completion of the dynamometer run and the exhaust and air cleaner inlet pipes will be replugged.

(4) Any vapor collection systems employed during this part of the test will be left intact for their continued use during the following part. Any part of the vapor collection system disconnected during this phase of the test will be reconnected for the following phase.

(c) Hot soak test. Upon completion of the dynamometer run, the test vehicle will be permitted to soak with hood down for a period of 1 hour at an ambient temperature between 76° F. and 86° F. This operation completes the test. The traps are disconnected and weighed according to § 85.82.

§ 85.75 Dynamometer operation cycle. (a) The following 7-mode cycle shall be followed in dynamometer operation tests.

(b) The following equipment will be used for dynamometer tests:

(1) Chassis dynamometer-equipped with power absorption unit and flywheels.

(2) Cooling fan-A fixed-speed fan will be used. It will have sufficient capacity to maintain engine cooling during sustained operation on the dynamometer and its air moving capacity shall not exceed 5,300 c.f.m.

§ 85.76 Dynamometer procedure.

(a) The vehicle shall be tested from a cold start. Four warmup cycles and five hot cycles make a complete dynamomcter run. Exhaust emission measurements for hydrocarbons and carbon monoxide will be performed during the four warmup cycles and during the sixth and seventh (hot) cycles.

(b) Special considerations:

(1) On rolls less than 20 inches in diameter, the drive wheel tires will be inflated to 45 p.s.i.g. in order to prevent tire damage.

(2) The vehicle will be nearly level when tested in order to prevent fuel distribution unusual from that normally observed.

(3) The cooling fan will be positioned between 8 and 12 inches from the grill and directed squarely at the radiator (exception: air-cooled engines) and the dynamometer run will be made with hood up.

(4) Flywheels giving equivalent inertia as shown in the following table shall be used. Flywheels giving heavier inertia may be used provided that the specified "equivalent inertia weight" is used in the formula for determining "Exhaust Volume." (See § 85.87 (g) (4) (iii).)

(c) The power absorption unit shall be adjusted to reproduce road load at 50 m.p.h. true speed.

(1) The proper horsepower setting for a particular vehicle-dynamometer combination is predetermined by:

(i) Measuring the absolute manifold vacuum of a representative vehicle of the same equivalent inertia weight class, when operated on a level road under balanced wind conditions at a true speed of 50 m.p.h., and

(ii) Noting the dynamometer horsepower setting required to reproduce that manifold vacuum, when the same vehicle is operated on the dynamometer at a true speed of 50 m.p.h.

(2) Where it is expected that more than 33 percent of the vehicles in an engine displacement class will be equipped with air conditioning, an additional 10 percent will be added to the road load horsepower, determined above, for all test vehicles representing such engine class.

(d) Practice cycles should be run to find the correct throttle action to allow completion of the accelerations in the specified time at the constant rates of acceleration specified. Care should be taken to avoid throttle closures in the transition from acceleration to 30 cruise.

(e) The vehicle speed (m.p.h.) as measured from the dynamometer rolls shall be used for all conditions. A speed vs. time recording, as evidence of dynamometer test validity, shall be supplied on request by the Secretary.

133 F.R. 8304, June 4, 1968, as amended at 34 F.R. 11096, July 1, 1969]

§ 85.77 Three-speed manual transmissions.

(a) All test conditions except as noted shall be run in highest gear.

(b) Cars equipped with free wheeling or overdrive units shall be tested with this unit (free wheeling or overdrive) locked out of operation.

(c) Idle: Idle shall be run with transmission in gear and with clutch disengaged (except first idle; see § 85.80).

(d) Cruise: The vehicle shall be driven at a constant throttle position to maintain the cruising speed. An engine tachometer and vacuum gauge may be used as driving aids.

(e) Acceleration: Modes shall be run at nearly constant acceleration with the shift speeds as indicated below (where possible; if not, cut into time of next mode). Shifting shall be accomplished rapidly to minimize closed-throttle time. Shift speed

Mode 0-25 accel_

15-30 accel------

1st to 2d gear at

(f) Deceleration: (1) The modes shall be run at closed throttle in high gear with clutch engaged, maintaining a constant deceleration rate by using the vehicle brakes. For those modes which decelerate to zero, the clutch should be depressed when speed drops below 15 m.p.h.

(2) If the vehicle decelerates more rapidly than required with no braking, the decelerations should be made at closed throttle even though less than the specified time is required. Indicate the end of the (30-15 or 20-0) deceleration, continue at that speed until the specified time has elapsed, then proceed with the next sequence.

(g) Optional shift points: When recommended by the manufacturer in the owner's operating manual, second gear may be used in sequences six and seven of § 85.75 (a). If this option is utilized, it shall be reported in test results submitted under § 85.51 and a copy of the applicable owner's operating manual shall be submitted with such report.

§ 85.78 Four- and five-speed manual transmissions.

(a) Use the same procedure as threespeed manual transmissions with the following exceptions:

(b) If transmission ratio in first gear exceeds five, follow the procedure for three-speed manual transmission vehicles as if the first gear did not exist.

(c) If an acceleration cannot be made within the specified time, reduce the time in the next steady speed mode to the extent necessary to compensate for time lost.

(d) Optional shift points: When recommended by the manufacturer in the owner's operating manual, second gear may be used in sequences six and seven of § 85.75(a). If this option is utilized, it shall be reported in test results submitted under § 85.51 and a copy of the applicable owner's operating manual shall be submitted with such report. § 85.79 Automatic transmissions.

(a) All test conditions shall be run with the transmission in "Drive" (highest gear).

(b) Idle: Idle shall be run with the transmission in "Drive" and the wheels braked (except first idle; see § 85.80).

(c) Cruise: The vehicle shall be driven at constant throttle position to maintain specified speed in highest gear.

(d) Accelerations: Modes shall be run at nearly constant acceleration, allowing the transmission to shift automatically through the normal sequence of gears.

(e) Decelerations: These modes shall be run at closed throttle, maintaining a constant deceleration by using the vehicle brakes. If the vehicle decelerates more rapidly than required, the test shall be

(a) The engine will be started according to the manufacturer's recommended starting procedure and run in the neutral position at no less than 1,100 r.p.m. (or maximum r.p.m. at which clutch remains disengaged if automatically operated) for a total of 20 seconds.

(b) Put the transmission in gear after 20 seconds so that the first acceleration can be started at the end of 40 seconds. The emissions for the first idle are to be read during the last 3 seconds preceding the first acceleration mode. This initial idle replaces the idle in the first 7-mode cycle.

(c) Vehicles equipped with manual choke shall be started according to the manufacturer's procedure. Use of the choke should not extend beyond sequence eight of the first cycle.

(d) Where necessary, in order to keep the engine running, the operator may use more choke, higher r.p.m., or decreased rate of acceleration.

[33 F.R. 8304, June 4, 1968, as amended at 34 F.R. 11096, July 1, 1969]

(b) Component description. The following components will be used in sampling and analytical systems for testing under the regulations in this part.

(1) Flowmeters FL1, FL2, FL3, and FL4 indicate the sample flow rate through the analyzers.

(2) Low range hydrocarbon analyzer.
(3) Carbon monoxide analyzer.
(4) Carbon dioxide analyzer.

(5) High range hydrocarbon analyzer. (6) Pressure gauges P1, P2, and P3 indicate the analyzer sample pressure.

(7) Needle valves N1, N2, N3, and N4 regulate sample flow rate to the analyzers.

(8) Needle valves N5, N6, N7, N8, N9, and N10 regulate the flow rates of N, and normalizing gases to the analyzers.

(9) Ball valves V1, V2, and V3 for directing either sample or calibration gases to the analyzers.

(10) Needle valves N11, N12, N13 regulate the sample flow rate through the bypass network.

(11) Flowmeters FL5, FL6, and FL7 indicate the flow rate through the bypass system.

(12) Pumps P1, P2, and P3 for pulling sample from source.

(13) Filters F1, F2, and F3 remove contaminants from sample prior to analysis.

(14) Ball valves V4, V5, and V6 for di

recting sample to the analyzer or directing air in the reverse direction as a blackflush.

(15) Toggle valves V8, V9, V10, and V11 for draining condensate traps and refrigerated bath.

(16) Traps T1, T2, and T3 for condensing water vapor and cooling exhaust sample.

(17) Ball valve V7 for diverting air to low HC analyzer during periods of high hydrocarbon response.

(18) Needle valve N14 for regulating air flow to low hydrocarbon analyzer during purge conditions.

(19) Thermometer for indicating bath temperature.

(20) Refrigerated water bath for condensing water vapor and cooling exhaust sample.

(21) Sample line from vehicle to analysis system.

(22) Sample probe to extract exhaust gas sample from terminus of vehicle exhaust system.

(23) Ball valve V12 for directing N, to hydrocarbon analyzers.