United States Environmental Protection Agency Office of Mobile Source Air Pollution Control Emission Control Technology Division 2565 Plymouth Road Ann Arbor, Michigan 48105 EPA 460/3-84-011 March 1985 oEPA Air Crankcase Emissions with Disabled PCV Systems ------- EPA 460/3-84-011 Crankcase Emissions with Disabled PCV Systems by Daniel A. Montalvo and Charles T. Hare Southwest Research Institute 6220 Culebra Road San Antonio, Texas 78284 Contract No. 68-03-3162 Work Assignment 19 EPA Project Officer: Craig A. Harvey EPA Branch Technical Representative: R. Bruce Michael Prepared for ENVIRONMENTAL PROTECTION AGENCY Office of Mobile Sources \ Emission Control Technology Division 2565 Plymouth Road Ann Arbor, Michigan 48105 March 1985 ------- This report is issued by the Environmental Protection Agency to report technical data of interest to a limited number of readers. Copies are available free of charge to Federal employees, current contractors and grantees, and nonprofit organizations - in limited quantities - from the Library Services Office, Environmental Protection Agency, 2565 Plymouth Road, Ann Arbor, Michigan 48105. This report was furnished to the Environmental Protection Agency by Southwest Research Institute, 6220 Culebra Road, San Antonio, Texas, in fulfillment of Work Assignment No. 19 of Contract No. 68-03-3162. The contents of this report are reproduced herein as received from Southwest Research Institute. The opinions, findings, and conclusions expressed are those of the author and not necessarily those of the Environmental Protection Agency. Mention of company or product names is not to be considered as an endorsement by the Environmental Protection Agency. Publication No. EPA 460/3-84-011 ii ------- FOREWORD This project was conducted for the U.S. Environmental Protection Agency by the Department of Emissions Research of Southwest Research Institute. The project was begun in May 1984 and completed in September 1984. It was conducted under Work Assignment 19 of Contract 68-03-3162, and was identified within Southwest Research Institute as Project 03-7338-019. Mr. Robert 3. Garbe of the Emission Control Technology Division, Office of Mobile Source Air Pollution Control, Environmental Protection Agency, Ann Arbor, Michigan, served as EPA Project Officer during the early part of the project. Mr. Craig A. Harvey was named EPA Project Officer during the latter part of the project. Mr. R. Bruce Michael, of the same division, was the Branch Technical Representative. Mr. Charles T. Hare, Manager, Advanced Technology, Department of Emissions Research, Southwest Research Institute, served as the Project Manager. The project was under the supervision of Daniel A. Montaivo, Research Scientist, who served as Project Leader. ill ------- ABSTRACT This report describes the laboratory testing of nine in-use light-duty gasoline passenger cars using up to four PCV disablement configurations. The nine vehicles included 1975 to 1983 model years, with odometer readings generally between 20,000 and 60,000 miles. No two vehicles were identical in make and engine type, and engine displacements ranged from 89 to 403 inA The vehicles were tested over the 1975 Federal Test Procedure, with sampling for crankcase HC conducted during each individual cycle of the 3-bag FTP and during the 10-minute hot soak. Emissions of crankcase HC are provided in g/mi for the 3-bag FTP, and in g/min for the 10-minute soak. Two PCV disablement configurations, identified as Al and A2 in this study, contributed significant crankcase HC emissions. Disablement Al was with the PCV valve disconnected from its orifice, but still connected to its hose going to the carburetor or manifold. The A2 disablement was like Al, but with the fresh air hose to the air cleaner completely removed. The 3-bag FTP crankcase HC emissions of the nine vehicles ranged from 0.16 to 2.72 g/mi (average 1.21 g/mi) using the Al configuration, and from 0.71 to 4.18 g/mi (average 1.92 g/mi) using the A2 configuration. Overall, A2 hydrocarbon emissions were about 59 percent higher than Al hydrocarbon emissions. Crankcase HC emissions with A2 disablement were two times greater than their respective Federal exhaust HC emissions standards, as averaged for eight cars. The crankcase HC emissions did not correlate strongly with odometer reading or engine displacement, although the larger-displacement engines (229 to 403 in^) did produce most of the higher HC readings of the study. Highest crankcase HC emissions during the 10-minute soak were 0.29 and 0.19 grams per minute found with the Al and A2 disablements, respectively. Methane was not a major constituent of crankcase emissions, the highest level detected during the FTP being 0.02 g/mi. IV ------- TABLE OF CONTENTS FOREWORD ABSTRACT iv LIST OF FIGURES vi LIST OF TABLES vii I. INTRODUCTION 1 II. SUMMARY AND CONCLUSIONS 2 III. TEST PLAN, VEHICLES, FUEL, AND TEST PROCEDURES 4 A. Test Plan k B. Test Vehicles 8 C. Dynamometer and CVS Sampling System 8 D. Sampling Interface System 13 E. Hydrocarbon Gaseous Emissions 16 F. Emission Test Procedure 16 G. Hydrocarbon Emissions Calculations 20 IV. GASEOUS HYDROCARBON EMISSIONS RESULTS 21 A. PCV Disablement Configurations Evaluation 21 B. Methane Analyses 21 C. Crankcase On-Line and Bag HC Emissions 25 D. FTP Crankcase On-Line HC Emissions 25 E. Crankcase HC Emissions During Soak 32 REFERENCES 3t APPENDICES A. WORK ASSIGNMENT NO. 19 SCOPE OF WORK AND MODIFICATIONS B. LIST OF AVAILABLE TEST VEHICLES AS OF JULY 1984 ------- LIST OF FIGURES Figure Page 1 PCV Disablement Configurations with Emissions Sampling System 7 2 Views of Gasoline Vehicles as Evaluated on Dynamometer 12 3 Sampling System Interfaces for HC in Gasoline Crankcase Gaseous Emissions 14 4 Views of the "Closed System" as Evaluated for Sampling of the Crankcase HC using the Monte Carlo 15 5 Setup of Sampling Interface System on Test Vehicles with PCV Disablements (Al and A2 Configurations) 17 6 Views of Gaseous HC Analytical Instruments 18 7 FTP Driving Cycle vs Time Trace 19 8 Crankcase HC Emissions of Nine Test Vehicles During 3-Bag FTP with PCV Disablement Configuration Al 26 9 Crankcase HC Emissions of Nine Test Vehicles During 3-Bag FTP with PCV Disablement Configuration A2 27 10 Crankcase On-Line THC Emissions of Nine Vehicles During 3-Bag FTP with PCV Disablement Configurations Al and A2 29 11 Crankcase On-Line THC Emissions of Nine Vehicles During Individual Cycles of 3-Bag FTP with PCV Disablement Configuration A2 31 12 Crankcase On-Line THC Emissions of Nine Test Vehicles During 10-Minute Soak of 3-Bag FTP with PCV Disablement Configurations Al and A2 33 vi ------- LIST OF TABLES Table 1 Summary of Gasoline Vehicles Evaluated for Crankcase Hydrocarbon Emissions with Disabled PCV Systems 4 2 Description of Gasoline Test Vehicles 9 3 Summary of Driving Schedule Parameters 19 4 Summary of Crankcase Hydrocarbon Emissions from Various Vehicles with Disabled PCV Systems 22 vzi ------- I. INTRODUCTION The earliest form of gasoline automotive emission control was the Positive Crankcase Ventilation (PCV) System. Gasoline engines produce variable quantities of blowby gases during their operating cycle that escape past the piston rings into the crankcase. These gases contain certain unburned fuel and other pollutants that may adversely affect the environment. Since the early 1960's, most gasoline vehicles have employed a PCV system to prevent blowby gases from escaping to the atmosphere. Current EPA regulations require systems which completely eliminate the venting of crankcase emissions from gasoline-fueled vehicles. A PCV system works by routing crankcase gases into a vacuum-controlled valve (PCV valve), and then through a hose into the carburetor orifice or intake manifold, where they are subsequently burned in the combustion chamber. Fresh air to the crankcase is normally drawn through a hose connected between the valve cover and air cleaner housing. An EPA tampering survey(D* has indicated that crankcase emissions from some in-use light-duty gasoline passenger vehicles are uncontrolled, due to disablement of the PCV system. Approximately 2885 vehicles were randomly examined, and of these, 2.5 percent had disabled PCV systems. Although the number of vehicles with disabled PCV was low, EPA is concerned that crankcase emissions could still have a major impact on total vehicle emissions. For example, if crankcase emissions are large, then the major gasoline vehicle pollutants would be those emitted from the crankcase and not from the exhaust. The study reported here measured crankcase HC emissions from nine in- use 1975 and later model year light-duty passenger gasoline vehicles, with four different configurations of PCV disablements. Crankcase hydrocarbon emissions were measured using normal CVS bags, as well as an on-line heated flame ionization detector (HFID). Methane analysis was also performed on the CVS bags. The dynamometer driving schedule used in the study was the 1975 3- bag Federal Test Procedure^), but included continuous HC sampling and a fourth bag collected during the hot 10-minute soak period. *Superscript numbers in parentheses refer to references at the end of this report. ------- IL SUMMARY AND CONCLUSIONS The major purpose of this project was to quantify crankcase HC emissions of nine in-use light-duty gasoline passenger vehicles with disabled PCV emissions control systems. Model years of the vehicles were from 1975 to 1983, with odometer readings generally from 20,000 to 60,000 miles. Engine displacements ranged from 89 to 403 in.3, and no two vehicles were identical in engine type or make. Sampling of crankcase HC emissions was conducted during each cycle of the 1975 3-bag FTP Federal Test Procedure and during the 10-minute hot soak. Hydrocarbon emissions were measured using normal CVS bags as well as an on-line heated flame ionization detector (HFID). Methane analysis was also performed on the CVS bags. Important observations and conclusions reached as a result of this project (not necessarily in order) are as follows: Of the four PCV disablement configurations (Al, A2, B3, and B4) evaluated in this study, only Al and A2 were found to be significant contributors (greater than 0.1 g/mi) of crankcase HC emissions. Disablement Al is with PCV valve disconnected from its orifice at the valve cover, and still connected to its hose going to the carburetor or manifold. The A2 disablement is like Al, but also with the fresh air hose to the air cleaner completely removed. Crankcase HC emissions of the nine vehicles sampled indicated levels of 0.16 to 2.72 g/mi, with an average of 1.21 g/mi, employing the Al disablement. Hydrocarbon emissions from the crankcase using the A2 disablement averaged 1.92 g/mi and a range of 0.71 to 4.18 g/mi. Eight of the cars with A2 configuration produced an average of two times as much crankcase HC as that specified for exhaust HC in their respective Federal exhaust emissions standards. Meaningful correlation of crankcase HC emissions with odometer reading, engine displacement, or engine type was not evident, although the larger displacement engines (229 to 403 in.3) did produce higher HC emissions (greater than 1.0 g/mi by on-line analysis). The Cougar with 351 in.^ engine displacement was the highest HC emitter at 4.18 g/mi (A2), and the Tercel with 89 in.3 displacement was the lowest with 0.16 g/mi (Al). Overall, the A2 disablement provided about half the 10-minute soak HC emissions obtained with the Al disablement. The Al configuration averaged 0.15 g/min HC emissions with a range of 0.00 to 0.29 g/min, while A2 varied from 0.02 to 0.19 g/min with an average value of 0.08 g/min. Highest crankcase on-line HC emitters during the 10-minute soak with Al disablement were the Chevette and Cougar at 0.29 and 0.28 g/min, respectively. The Cougar and Skyhawk were the highest HC emitters, at 0.19 g/min, using the A2 disablement. ------- Methane was not a major constituent of crankcase HC emissions, the highest ievel detected (from the Chevette, 98 CID) during the 3-bag FTP being 0.02 g/mi. The 3-bag FTP methane ranged from O.'fl to 1.1 percent of bag HC. No methane was detected, at a detection limit of 0.005 g/min, during the soak cycle on any vehicle. ------- IIL TEST PLAN, VEHICLES, FUEL, AND TEST PROCEDURES This section describes the test plan, vehicles, fuel, and test procedures. The facilities and general instrumentation are also discussed. A. Test Plan A copy of the Scope of Work and subsequent additions for this Work Assignment, are given in Appendix A. The intent of the test plan was to evaluate or quantify crankcase HC emissions from gasoline passenger vehicles with disabled PCV systems. Consequently, in this project, nine gasoline vehicles were actually operated. The test plan called for ten vehicles, but only nine were run because of costs incurred evaluating two added and distinct PCV disablements identified later in this discussion. The vehicles employed in the study are identified in more detail later in the report under Subsection B of Section III. For the sake of discussion in this section, however, a brief description of the vehicles with corresponding SwRI code is provided in Table 1. TABLE 1. SUMMARY OF GASOLINE VEHICLES EVALUATED FOR CRANKCASE HYDROCARBON EMISSIONS WITH DISABLED PCV SYSTEMS Vehicle Code 01 02 03 05 06 07 08 09 Year Vehicle and Engine Description Make 1982 Chevrolet 1978 Mercury 1982 Toyota 1975 Chevrolet 1977 Buick 1978 Oldsmobile 1983 Dodge 1978 Toyota 1978 Chevrolet Model Monte Carlo Cougar Tercel Nova Skyhawk Delta 88 Aries Celica Chevette Engine Odometer Displacement, Miles 20,983 45,770 31,875 58,156 57,234 69,418 20,728 52,214 44,139 l/in.3 3.8/229 5.8/351 1.5/89 4.1/250 3.8/231 6.6/403 2.2/134 2.2/134 1.6/98 The vehicles are not a statistical sample, but represent a wide range of cars. Mileages were chosen to represent typical averages instead of extremes. As specified in the test plan, no two vehicles were identical in make and engine type, and their odometer readings were generally from 20,000 to 60,000 miles. Only one vehicle, a 1978 Oldsmobile Delta 88, exceeded 60,000 miles; and it was 4 ------- tested with the Project Officer's approval. Two of the test vehicles used were in each of the following displacement classes selected by the Project Officer, except for the single vehicle in the 4.0-5.6 I class: Vehicle Tested Displacement Class 03 and 09 under 1.7 A (<104 in.3) 07 and 08 1.8-2.5 A (110-153 in.3) 01 and 05 2.6-3.9 £ (159-238 in.3) 04 4.0-5.6 H (244-343 in.3) 02 and 06 greater than 5.7 I (>348 in.3) The basic test sequence and HC emission measurements conducted on each vehicle/PCV disablement combination were the following: Test Sequence (3-bag FTP and 10-minute soak) Emissions Measurements Continuous heated FID THCa CVS bag HC CVS bag Methane Cold Transient Xb X X Cold Stabilized X X X Hot 10-min. Soak X X X Hot Transient X X X aTHC is total hydrocarbons bx indicates a sample is taken Continuous HC was obtained during the 3-bag FTP, and also during the hot 10- minute soak. Concurrently, the normal CVS bag was obtained for each cycle including the soak. The bags were used to determine HC and methane. Emissions during the soak are reported separately from the 3-bag FTP. The analytical instrumentation for continuous THC, bag HC, and bag methane is described later in the report, in Section III, E. Each vehicle was to be tested once over the "four-bag" FTP (as previously described for the three normal bags plus a 10-minute fourth bag sampled during the hot soak) with the following PCV configurations: Disablements A. PCV valve disconnected from its orifice which receives crankcase emissions, and still connected to its hose going to carburetor or manifold. Disablement Al. PCV disconnected; fresh air hose to air cleaner connected. ------- Disablement A2. PCV disconnected; fresh air hose to air cleaner completely removed and no part of the system plugged. Disablements B. New disablements added Disablement B3. PCV valve remains connected in orifice, but disconnected from hose going to carburetor or manifold; fresh air hose system intact. Disablement B4. Fresh air hose to air cleaner completely removed; PCV system properly connected. The new disablements (B3 and B4) were added to Al and A2 as a technical direction by the Project Officer (See Appendix A). A schematic representation of these PCV disablements is found in Figure 1. Included in the figure are the proposed emissions sampling points. As described later in the report under Section IV, the B3 and B4 disablements were discontinued by the Project Officer after preliminary testing showed that crankcase HC emissions with these two disablements were not significant as compared to Al and A2. Disablement configurations Al and A2 were each run with each vehicle, using the four-bag FTP. The Monte Carlo was the only vehicle that was run twice using the A2 disablement and "four-bag" FTP, to check the sampling system repeatability. The Monte Carlo, Cougar, and Tercel were the only cars run using the B3 and B4 disablements. Each of these three cars was run once with B3 using a cold-505 cycle, and once with B4 using a hot-505 cycle. Three techniques considered early in this project to measure crankcase HC emissions included the following: 1. Measure HC concentration of gases emitted by collecting them in a bag or with a continuous FID, and determine total volume emitted separately to permit computation of mass emissions. 2. Introduce crankcase gases into a low-volume calibrated dilution system and use bag sampling, with computation similar to that used for a standard CVS to yield grams per mile. 3. Introduce gases into a standard CVS dilution system, and use continuous or bag sampling to determine HC concentration, followed by standard CVS computations to yield grams per mile. Technique No. 3 was ultimately selected because it required the least complex efforts to set-up, sample, and calculate emissions results. The technique also provided bag samples of reasonable concentration for methane analysis. The CVS system designated for use in this study is described later in this report under Section III. C. ------- Air Cleaner 1 Valve Cover(s) Carburetor or Manifold TYPE IV SYSTEM OT ouro Typical PCV System with PCV and fresh air hose properly connected Air Cleaner t Carburetor or Manifold ^ <. PCV Valve Cover (s) + Sampling System Air Cleaner I Carburetor or Manifold PCV Valve Cover(s) Sampling System CVS Tunnel CVS Tunnel Al-Disablement Configuration with PCV disconnected; fresh air hose to air cleaner connected A2-Disablement Configuration with PCV disconnected; fresh air hose to air cleaner completely removed and no part of the system plugged. Air Cleaner ± Carburetor or Manifold Valve Cover(s) Sampling System CVS Tunnel B3-Disablement Configuration with PCV valve connected in orifice, but disconnected from hose going to carburetor or manifold; fresh air hose system intact. B4-Disablement Configuration with air hose to air cleaner completely removed; PCV system properly connected. Figure 1. PCV disablement configurations with emissions sampling points ------- B. Test Vehicles A request for vehicles that could become available for study in this project was issued to staff members of Southwest Research Institute and its sister organization, Southwest Foundation for Biomedical Research. A copy of the request, along with a listing of vehicles submitted by the staff members for consideration, are found in Appendix B. This list proved very helpful in enabling SwRI and the Project Officer to obtain vehicles that closely fitted the test plan vehicle constraints identified earlier in Section III. A. A full description of the vehicles is provided in Table 2. Prior to accepting a vehicle for testing, the vehicle was run on the dyno to determine driveability, and to check for exhaust system leaks that could affect laboratory HC background. Any vehicle that had prior major engine repair, including a valve job, was disqualified from testing. The emission control system was also examined for proper connection. Of the nine vehicles tested, the Cougar, Skyhawk, and Chevette required replacement of the muffler; and no vehicle showed evidence of extreme negligence or intentional tampering with the PCV system. After the preliminary checks were found in order, the fuel tank was filled with unleaded gasoline, if needed, to a minimum three-quarter full level. Makeup oil was added to the crankcase only if the oil level was found below safe limits. During testing, only the Chevette showed a little oil leakage underneath the engine region, but no oil makeup was necessary. Views of two vehicles used in the overall 9-vehicle study are shown in Figure 2, as evaluated on the dynamometer. No significant operating difficulties were experienced with the nine cars during this project. Engine operation or response on the cars was not noticeably affected by the Al, A2 and B4 disablements; but use of the B3 disablement did produce some apparent roughness of the engines in the Monte Carlo, Cougar, and Tercel. Although not requested, a measurement of engine compression and cylinder leak-down time could have provided interesting information to explain differences in crankcase emission levels. C. Dynamometer and CVS Sampling System A 50 hp Clayton ECE-50 passenger car dynamometer was used for the emission testing on this project. The dynamometer has a direct-drive variable inertia system for simulation of vehicle mass from 454 kg (1000 Ib) to 4082 kg (9000 Ib) in 57 kg (125 Ib) increments. The constant volume sampler (CVS) used for these studies was SwRI CVS No. 3, ordinarily used for light-duty diesel applications. The diesel CVS was selected over a gasoline CVS because the former incorporates a heated probe used for on-line THC sampling by heated flame ionization detector (HFID). A 460 mm (18 in.) diameter by 5 m (16 ft) long dilution tunnel was used in conjunction with the CVS, which operated at a nominal flowrate of 9.7 m^/min (344 cfm). This flowrate compares to 9.1 m^/min. (320 cfm) used in the light- duty gasoline CVS system at this laboratory. A sampling interface system was prepared by SwRI for use between the normal PCV/fresh air hose orifice and the sample inlet of the dilution tunnel. The sampling interface system is described in Section III. D. ------- TABLE 2. DESCRIPTION OF GASOLINE TEST VEHICLES SwRI Vehicle Code Vehicle Make Model Model Year Body Type Vehicle Identification No. 01 Chevrolet Monte Carlo 1981 2-door 1G1A237K3BR456455 02 Mercury Cougar 1978 2-door 8H93H697782 03 Toyota Tercel 1982 2-door 3T2AL25G7C4465569 Chassis Dynamometer Setting: Inertia, kg (Ibs) 1644(3625) Power, kW (hp) 7.9(10.6) 2041(4500) 7.8(10.4) 1021(2250) 6.0(8.0) Engine I.D. Engine Displacement Cylinders Carburetion (in.3) 3.8(229) V8 2V 5.7(351) V8 2V 3A1390788 1.5(89) L4 2V Emission Controls3 EGR/PMP/OXD/ 3CL/CAN EGR/PMP/ OXD/CAN EGR/PLS/OXD/ CAN Transmission Tires A3 P195/75R14 A3 GR78-S15 M5 165/70-SR13 Air Conditioning Power Steering Power Brakes Yes Yes Yes Yes Yes Yes Yes Yes Yes Vehicle Odometer, km (mi) 33759(20983) 73660(45770) 51298(31875) aEGR (exhaust gas recirculation), PMP (air pump), OXD (oxidation catalyst), 3CL (three-way catalyst with closed loop fuel system), CAN (carbon canister storage evaporative emissions), PLS (pulsating air system), EFE (early fuel evaporation) ------- TABLE 2 (CONT'D). DESCRIPTION OF GASOLINE TEST VEHICLES SwRI Vehicle Code Vehicle Make Model Model Year Body Type Vehicle Identification No. 04 Chevrolet Nova 1975 4-door LX69DJL149542 05 Buick Skyhawk 1977 2-door 4T07A72722472 06 Oldsmobile Delta 88 1978 2-door 3N37K8C149929 Chassis Dynamometer Setting: Inertia, kg (Ibs) 1814(4000) Power, kW(hp) 8.9(12.0) 1588(3500) 9.2(12.3) 2041(4500) 10.4(14.0) Engine I.D. Engine Displacement Cylinders Carburetion 348675GM86 (in.3) 4.1(250) L6 IV 3.8(231) V6 2V 6.6(403) V8 4V Emission Controls3 EGR/OXD/EFE/ CAN EGR/OXD/ EFE/CAN EGR/OXD/CAN Transmission Tires M3 P185/75-14R A3 P165/80B13 A3 205SR/15 Air Conditioning Power Steering Power Brakes No No No Yes Yes Yes Yes Yes Yes Vehicle Odometer, km (mi) 93593(58156) 92109(57234) 111694(69418) aEGR (exhaust gas recirculation), PMP (air pump), OXD (oxidation catalyst), 3CL (three-way catalyst with closed loop fuel system), CAN (carbon canister storage - evaporative emissions), PLS (pulsating air system), EFE (early fuel evaporation) 10 ------- TABLE 2 (CONT'D). DESCRIPTION OF GASOLINE TEST VEHICLES SwRI Vehicle Code Vehicle Make Model Model Year Body Type Vehicle Identification No. 07 Dodge Aries 1983 4-door 1B3BD26C50C176803 08 Toyota Celica 1978 2-door RA42044389 09 Chevrolet Chevette 1978 2-door 1BD8E8Y267201 Chassis Dynamometer Setting: Inertia, kg (Ibs) 1247(2750) Power, kW(hp) 6.0(8.1) 1247(2750) 8.1(10.9) 1134(2500) 7.7(10.3) Engine I.D. Engine Displacement (in.3) 2.2(134) Cylinders L4 Carburetion 2V 2.2(134) L4 2V 1.6(98) L4 IV Emission Controls3 EGR/PMP/OXD/ 3CL/CAN EGR/PMP/ OXD/CAN EGR/OXD/CAN Transmission Tires A3 P175/75R13) M5 185/70R14 A3 155/SR13 Air Conditioning Power Steering Power Brakes Yes Yes Yes Yes Yes Yes Yes No No Vehicle Odometer, km (mi) 33371(20736) 84030(52214) 71033(44139) aEGR (exhaust gas recirculation), PMP (air pump), OXD (oxidation catalyst), 3CL (three-way catalyst with closed loop fuel system), CAN (carbon canister storage evaporative emissions), PLS (pulsating air system), EFE (early fuel evaporation) 11 ------- 1978 Mercury Cougar 1977 Buick Skyhawk Figure 2. Views of gasoline vehicles as evaluated on dynamometer ! .' ------- D. Sampling Interface System Two sampling interface systems were evaluated for use between the PCV/fresh air hose orifices and the CVS tunnel. Each system provides for fresh air to be drawn through it, thus not creating an unrealistic vacuum at the orifices. The two sampling systems are shown schematically in Figure 3. One system is identified as a "closed system," and the other as an "open system." Both systems were initially evaluated for proper operation in conjunction with the Monte Carlo. The "closed system" contains a stainless steel cylindrical mixing chamber (4 in. O.D. x 6 in. long), which allows filtered makeup air, pumped out of the CVS filter box, to mix with crankcase emissions before being drawn into the tunnel via a heated (375°F) 1/2-inch Teflon line. Figure 4 provides views of the "closed system" as evaluated on the Monte Carlo. At the start of testing with the test vehicle, the sampling line at the PCV orifice is pulled out and capped, while makeup air to atmosphere and mixing chamber is simultaneously adjusted with the valve to provide a vacuum reading of 0.5 in. H20 at the orifice. Using the "closed system" during a 2-bag FTP with the Al PCV disablement, the tunnel draw through the small heated sample line did not sufficiently compensate for observed crankcase positive pressure increases. Concern was expressed that under these conditions, a "realistic" sampling of crankcase emissions was not occurring, and that venting of some emissions to atmosphere was likely. Therefore, no further evaluation of the "closed system" was attempted. In the "open system," a 2-inch diameter by 16-foot long rigid stainless steel tube was prepared to reach from the tunnel to the engine compartment. The tube sampling end was extended six inches with a tube assembly that terminates at a 4-inch diameter. One end of a 5/8-inch Teflon sampling line was used to sample emissions at the PCV orifice through a rigid tube that matches the diameter of the PCV valve in order to form a close fit at the orifice. Throughout this project, either a short, rigid metal tube or a rubber hose was used at the end of the Teflon sampling line to attach snugly to the PCV and fresh air hose orifices as each engine design required. The other end of the Teflon line was inserted into the open end of the 4-inch line, thus allowing ambient makeup air to also enter the tunnel (for use in on-line HC emissions calculations, the tunnel HC background is measured as sampled at the 4-inch tube without insertion of the Teflon line). The required depth of insertion into the 4-inch opening is determined by setting the pressure gauge to 0.5 in. H20 vacuum with the Teflon sampling line capped, and removed from the PCV orifice. The cap is removed before the line is reinserted into the PCV orifice. The Project Officer approved the continued use of the "open system" after a trial 2-bag FTP test with the Al disablement configuration showed that tunnel draw at the 2-inch tube was sufficient to prevent crankcase emissions from escaping to atmosphere, even at positive crankcase pressures during moderate-to high-rate accels. Testing of front-wheel-drive vehicles required that the 2-inch diameter rigid sampling tube be shortened to 8 feet in order to accommodate the open end of the tube closer to their engine compartments. The 2-inch rigid tube was shortened using two tube unions that were also used to reassemble the 16-foot 13 ------- CVS CVS Tunnel Tunnel Air Filter Box Vent To Atmosphere Pump Heated 0.5 in. O.D. S.S. Tube "CLOSED SYSTEM" Air Filter Box 2 in. O.D. S.S. Tube "OPEN SYSTEM" Valve Engine Valve Cover PCV Orifice Pressure Engine Valve Cover Makeup Air * PCV / Orifice Pressure Figure 3. Sampling system interfaces for HC in gasoline crankcase gaseous emissions ------- •*'—* Figure 4. Views of the "closed system" as evaluated for sampling of crankcase HC using the Monte Carlo ! , ------- long sampling tube configuration as needed for use with rear-wheel-drive test cars. The A2 disablement configuration also required two separate Teflon sampling lines in order to simultaneously, but separately, sample at the PCV and fresh air hose orifices as requested by the Project Officer. As with the Al disablement, the Teflon lines were similarly inserted into the open end of the 2- inch sampling tube to a sufficient depth (approximately 6 to 8 inches) to enable setting the pressure gauge readings to 0.5 in. H^O vacuum with sampling lines capped and removed from the orifices. Various views of the sampling interface system used on test vehicles with the Al and A2 disablement configurations are shown in Figure 5. E. Hydrocarbon Gaseous Emissions Once the crankcase emissions are introduced into the CVS tunnel; as previously explained for the sampling interface system in Section III, D., the emissions are collected and analyzed using the same procedures and equipment described in the Code of Federal Regulations^/ for regulated exhaust hydrocarbons. Hydrocarbon analysis of the sample was continuous, using a heated flame ionization detector (HFID), as is normally employed for light-duty diesel HC exhaust emissions. Electronic signal integration used with the HFID provided average dilute hydrocarbon concentration for each test cycle. The gaseous sample was taken directly from the diluted exhaust stream through a heated probe in the dilution tunnel. The gaseous emissions, as obtained in Tedlar bags at the CVS, were also analyzed for HC using the same HFID instrument employed for the on-line hydrocarbons, but with direct injection into the instrument after each 3-bag FTP test was completed. The same bags were then used to analyze for methane emissions using a GC FID procedure similar to that in the Recommended Practice SAE ail51.(3) Views of the HFID and methane analytical instruments are given in Figure 6. F. Emission Test Procedure The emission test procedure utilized in this project, as briefly identified earlier in Section III. A., is further defined as follows: FTP - Federal Code of Regulations^2) - The FTP uses the Urban Dynamometer Driving Schedule (UDDS), which is 1372 seconds in duration. The FTP schedule is illustrated in Figure 7. The UDDS, in turn, is divided into two segments; the first having 505 seconds and the second having 867 seconds. The FTP consists of a cold-start 505 (cold transient) and a stabilized 867 (cold stabilized), followed by a ten-minute soak and then a hot-start 505 (hot transient). In this project, crankcase emissions were also collected and measured during the 10-minute soak period in a fourth bag. The HC emissions from the fourth-bag are reported separately, i.e., not averaged in with 3-bag FTP results. A summary of the driving schedule parameters is presented in Table 3. 16 ------- PCV Disablement (Al Configuration) PCV Disablement (A2 Configuration) PCV Disablement (Al Configuration) PCV Disablement (A2 Configuration) Figure 5. Setup of sampling interface system on test vehicles with PCV disablements (Al and A2 configurations) ------- Continuous and Bag HC Analyzer Methane Analysis Figure 6. Views of gaseous HC analytical instruments 18 ------- .TRANSIENT PHASE STABILIZED PHASE 200 400 600 800 TIME, sec 1000 1200 Figure 7. FTP driving cycle vs time trace TABLE 3. SUMMARY OF DRIVING SCHEDULE PARAMETERS Driving Schedule FTP: Cold 505 Stab 867 10-min soak Hot 505 Duration, Seconds 505 867 600 505 Distance, Kilometers 5.8 6.2 — 5.8 Average Speed km/hr mph 41.3 25.7 25.8 16.2 — 41.3 25.7 1371 The step-sequence for running a 3-bag FTP/soak crankcase emissions test with the Al disablement configuration on a vehicle was as follows: Step 1 -Prep the vehicle with UDDS cycle Step 2 -Just before cold-start next day, determine laboratory HC background with on-line HFID as sampled through rigid 2-inch sampling tube into CVS tunnel. This initial HC background reading is used with a final on-line HC background reading after test, to correct on-line HFID HC readings taken during the 3-bag FTP and soak. Step 3 -Insert one end of Teflon sampling line into open end of 2-inch rigid tube to set tunnel draw at 0.5 in. H20 (vacuum), with the other end of Teflon line capped and removed from PCV orifice. Step 4 -Remove the Teflon line from the 2-inch tube. Uncap sampling end and insert into the PCV orifice. Step 5 -Immediately upon start of cold 505 cycle, insert the Teflon line into the 2-inch tube to the required depth determined in Step 3 and secure with built-in clamp. 19 ------- Step 6 -Run the 3-bag FTP and 10-minute soak in the order shown in Table 3. Continuously measure on-line HC with HFID, and obtain one CVS bag per each cycle. Step 7 -Remove Teflon sampling line at 2-inch tube as soon as the hot 505 cycle is completed. Step 8 -Measure final laboratory HC background with on-line HFID as was done in Step 2. Step 9 -Measure CVS bag HC with HFID, and then bag methane with FID. The preceding step-sequence is identical to that used with the A2 disablement configuration; but in the case of A2, one Teflon sampling line is used at the PCV orifice and another at the fresh air hose orifice in Steps 3, 4, 5, and 7. G. Hydrocarbon Emissions Calculations After each test and validation of correct test procedure, the crankcase HC values in: 1) integrator counts from on-line HFID; 2) ppmC from bag HFID; and 3) ppmC from the methane FID are entered into the CDC CYBER 172 computer via a data entry terminal. The emissions data are then processed according to the data reduction procedures recommended in the Code of Federal Regulations'2). Dummy values for CO, NOX, and CC>2 are entered in the program to permit the program to run. Fuel carbon and density values used are those specified for emissions type unleaded gasoline in the Code of Federal Regulations/2) Separate runs are made on the computer for on-line HC, bag HC alone, and both bag HC and bag methane together. The latter calculation provides emissions results for nonmethane HC (NMHC). Crankcase HC emissions are reported in g/mi for the 3-bag FTP, and in g/min for the hot soak. 20 ------- IV. GASEOUS HYDROCARBON EMISSIONS RESULTS A discussion of the crankcase hydrocarbon emissions obtained with the nine test vehicles evaluated in this program is presented in this section. Included in this discussion is the initial study of the four PCV disablement configurations proposed for evaluation, as well as results of the "3-bag FTP plus Soak" crankcase HC emissions analyses by on-line continuous HFID, bag HFID, and bag methane FID. A. PCV Disablement Configurations Evaluation The proposed disablement configurations of a PCV emissions control system were identified earlier in Section III. A. as Al, A2, B3, and B4. The four configurations were evaluated with the first three cars studied, which included the Monte Carlo, Cougar, and Tercel. Crankcase HC emissions of the three cars are summarized in Table ^ along with similar emissions of the remaining six cars subsequently evaluated using only PCV disablements Al and A2. All data in Table 4 were obtained employing the "open system" sampling interface discussed in Section III. D. Disablement A2 was run twice with the Monte Carlo to confirm sampling system repeatability. Results in Table 4 show that emissions repeatability was adequate. Disablements B3 and B4 were not significant HC emitters (not greater than 0.01 g/mi) as measured under cold and hot FTP 505 cycles, respectively. It would appear that with B3, the PCV spring is sufficiently strong to stop vapors from reaching the sampling system (normally run at 0.5 in. H20 vacuum). Under these conditions, the vapor may be preferentially drawn into the carburetor via the fresh air hose. In B4, the PCV correctly allows most vapors to enter the carburetor hose orifice as intended, thereby greatly limiting emissions as sampled at the fresh air hose orifice on the valve cover. Based on these results, the Project Officer requested that no further evaluation of B3 and B4 disablements be conducted, and that remaining emissions studies be conducted using only the Al and A2 configurations. B. Methane Analyses Methane was not a major constituent of crankcase bag HC emissions as determined in this study. The highest methane level detected during the 3-bag FTP was 0.02 g/mi using the A2 disablement with the Chevette. Other vehicles that produced crankcase methane, but at levels not higher than 0.01 g/mi, were the Monte Carlo, Cougar, Nova, Skyhawk, Delta 88, and Aries. Overall, methane was present rather sporadically during the 3-bag FTP, with no strong trend established for its presence on a particular cycle or during the two PCV disablements. No methane was detected (at detection limit of 0.005 g/min) during the soak cycle on any vehicle. 21 ------- TABLE 4. SUMMARY OF CRANKCASE HYDROCARBON EMISSIONS FROM VARIOUS VEHICLES WITH DISABLED PCV SYSTEMS Date 7/10/84 7/11/84 7/17/84 Avg. of 7/11/84 & 7/17/84 7/12/84 7/12/84 7/20/84 7/23/84 7/24/84 Vehicle Monte Carlo Monte Carlo Monte Carlo Monte Carlo Monte Carlo Monte Carlo Cougar Cougar Cougar PCV Disablement Configuration Al A2 A2 A2 B3 B4 Al A2 B3 HC Emissions, g/mi HC Measurement On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane Cold Transient 0.59 0.57 0.00 0.76 0.76 0.00 0.79 0.75 0.01 0.78 0.76 0.01 0.01 0.00 0.00 __ — 0.98 0.90 0.01 1.52 1.46 0.01 0.00 0.00 0.00 Cold Stabilized 2.44 2.35 0.00 2.43 2.34 0.00 2.52 2.37 0.00 2.48 2.36 0.00 -._ ™~" __ ~— 3.68 3.32 0.01 5.51 5.03 0.00 — _ —_ Hot Transient 1.55 1.51 0.00 1.65 1.54 0.00 1.77 1.65 0.00 1.71 1.60 0.00 — _ — 0.01 0.00 0.00 2.20 1.99 0.00 3.65 3.43 0.01 «» 3-Bag FTP 1.82 1.75 0.00 1.87 1.80 0.01 1.96 1.84 0.00 1.92 1.82 0.01 __ — .»— — 2.72 2.46 0.01 4.18 3.86 0.00 __ — ^ Hot Soak, g/min 0.15 0.15 0.00 0.06 0.05 0.00 0.03 0.03 0.00 0.05 0.04 0.00 0.28 0.24 0.00 0.19 0.20 0.00 ------- Date TABLE 4 (CONT'D). SUMMARY OF CRANKCASE HYDROCARBON EMISSIONS FROM VARIOUS VEHICLES WITH DISABLED PCV SYSTEMS Vehicle 7/24/84 Cougar 7/26/84 Tercel K) 7/27/84 7/30/84 7/30/84 8/1/84 8/2/84 8/7/84 8/8/84 Tercel Tercel Tercel Nova Nova Skyhawk Skyhawk PCV Disablement Configuration B4 Al A2 B3 B4 Al A2 Al A2 HC Measurement On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane Cold Transient „ — 0.05 0.05 0.00 0.32 0.31 0.00 0.00 0.00 0.00 __ :: 0.23 0.24 0.00 0.81 0.74 0.00 0.69 0.59 0.00 0.85 0.71 0.00 HC Emissions, Cold Stabilized — *™ 0.23 0.25 0.00 0.92 0.91 0.00 — _ "•" _— — ™ 1.52 1.51 0.01 2.09 1.98 0.01 2.39 2.22 0.00 2.90 2.63 0.01 g/mi Hot Transient 0.00 0.01 0.00 0.10 0.12 0.00 0.60 0.60 0.00 _ — — 0.00 0.00 0.00 0.89 0.84 0.00 1.56 1.49 0.00 1.46 1.39 0.00 1.76 1.64 0.00 3-Bag FTP — 0.16 0.17 0.00 0.71 0.70 0.00 — _ — __ — 1.08 1.06 0.00 1.68 1.59 0.01 1.79 1.66 0.00 2.16 1.96 0.00 Hot Soak, g/min — 0.06 0.06 0.00 0.04 0.05 0.00 M«. __ — 0.10 0.08 0.00 0.04 0.06 0.00 0.18 0.17 0.00 0.19 0.19 0.00 ------- Date TABLE 4 (CONPD). SUMMARY OF CRANKCASE HYDROCARBON EMISSIONS FROM VARIOUS VEHICLES WITH DISABLED PCV SYSTEMS Vehicle 8/9/84 8/17/84 8/20/84 8/22/84 8/23/84 Delta 88 8/10/84 Delta 88 8/14/84 Aries 8/15/84 Aries Celica Celica Chevette Chevette PCV Disablement Configuration Al A2 Al A2 Al A2 Al A2 HC Measurement On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC BagHC Bag Methane On-line THC Bag HC Bag Methane On-line THC BagHC Bag Methane Cold Transient 0.42 0.41 0.01 1.14 1.12 0.01 0.36 0.36 0.01 0.40 0.35 0.00 0.11 0.08 0.00 0.32 0.28 0.00 0.04 0.03 0.01 0.79 0.60 0.02 HC Emissions Cold Stabilized 2.11 2.02 0.00 3.23 3.07 0.00 1.43 1.39 0.00 1.44 1.39 0.00 0.90 0.79 0.00 1.04 0.98 0.00 0.33 0.29 0.00 2.98 2.62 0.01 , R/mi Hot Transient 0.94 0.89 0.00 2.16 2.01 0.00 0.97 0.94 0.00 0.99 0.93 0.00 0.32 0.33 0.00 0.78 0.73 000 0.11 0.16 0.00 1.63 1.43 0.01 3-Bag FTP 1.45 1.38 0.00 2.51 2.38 0.01 1.08 1.05 0.00 1.10 1.05 0.00 0.57 0.52 0.00 0.82 0.77 0.00 0.21 0.20 0.00 2.16 1.88 0.02 Hot Soak, g/min 0.15 0.14 0.00 0.03 0.04 0.00 0.00 0.03 0.00 0.05 0.01 0.00 0.10 0.08 0.00 0.02 0.05 0.00 0.29 0.25 0.00 0.07 0.09 0.00 ------- In an earlier EPA study(^) of 1970 model year non-catalyst light-duty gasoline passenger cars, SwRI determined that exhaust HC emissions contained from 3.6 to 6.8 percent (average 4.8 percent) methane. The 3-bag FTP methane levels in the crankcase in Table 4, by comparison, were 0.41 to 1.1 percent of bag HC. Excluding the Chevette cold transient methane results, individual cycles of the FTP produced methane in the range of 0.29 to 3.3 percent bag HC. C. Crankcase On-Line and Bag HC Emissions Crankcase HC emissions results in Table 4, determined on the 3-bag FTP using on-line and bag HFID analyses, are illustrated in Figures 8 and 9 for PCV disablements Al and A2. respectively. Included in the figures are the Federal HC Emissions Standards for light-duty passenger vehicle exhaust emissions which are 1.5 g/mi for model years 1975 through 1979, and 0.41 g/mi for model years 1980 to present. Figures 8 and 9 indicate that the 3-bag FTP on-line HC was generally higher than bag HC throughout the study. The Al disablement with the Tercel was the only time where 3-bag FTP bag HC was higher than on-line HC, and that only by 6 percent or 0.01 g/mi. On-line HC ranged from one to 13 percent (overall average 6 percent) higher than bag HC. The four vehicles showing larger differences than 7 percent between 3-bag FTP on-line and bag HC were the Cougar with Al (10 percent or 0.26 g/mi) and A2 (8 percent or 0.32 g/mi), Skyhawk with A2 (9 percent or 0.20g/mi), Celica with Al (9 percent or 0.05 g/mi), and Chevette with A2 ( 13 percent or 0.28 g/mi). Results for individual cycles of the 3-bag FTP in Table 4 also indicate the tendency of on-line HC to exceed bag HC. The average difference of on-line HC over bag HC was 8 percent. In a few cycles (Tercel-A1 and Nova-Al), where bag HC was higher than on-line HC, the differences averaged 11 percent, which translates to only about 0.02 g/mi. On-line and bag HC readings during soak were generally similar, with four tests showing equal readings. Nine tests had higher on-line HC than bag HC, while seven tests had higher bag HC than on-line HC. However, all of the differences between on-line and bag HC were within 0.04 g/min. Since this study has shown that on-line HC is generally higher than bag HC, subsequent discussions of crankcase emissions in this report will employ only the on-line HC data for ease of comparison between different PCV disablements during the 3-bag FTP and soak. D. FTP Crankcase On-Line HC Emissions Crankcase on-line HC emissions on the 3-bag FTP with the nine cars, as shown in Table 4, are compared to Federal exhaust HC emission standards for the same models in the following summary: 25 ------- 5t- 0 Vehicle Year Odometer, mi Eng.Disp. ,in." Eng.Type On-line THC Bag HC Figure 8. Crankcase HC emissions of nine test vehicles during 3-bag FTP with PCV disablement configuration Al. ------- 5,- On-line THC Bag HC Odometer, mi 32K Eng.Disp.,in. 89 Eng.Type L4 Figure 9. Crankcase HC emissions of nine test vehicles during 3-bag FTP with PCV disablement configuration A2 ------- 3-bag FTP Crankcase 3-bag FTP On-Line HC Emissions, g/mi Federal Exhaust HC PCV Disablement Vehicle Emissions Standard, g/mi Al A2 Monte Carlo 0.41 1.82 1.92 Cougar 1.5 2.72 4.18 Tercel 0.41 0.16 0.71 Nova 1.5 1.08 1.68 Skyhawk 1.5 1.79 2.16 Delta 88 1.5 1.45 2.51 Aries 0.41 1.08 1.10 Celica 1.5 0.57 0.82 Chevette 1.5 0.21 2.16 Average 1.21 1.92 Cars with crankcase HC emissions exceeding their respective Federal exhaust HC emission standards included the Monte Carlo (Al and A2), Cougar (Al and A2), Tercel (A2), Nova (A2), Skyhawk (Al and A2), Delta 88(A2), Aries (Al and A2), and Chevette (A2). Most cars showed higher crankcase emissions than the 0.41 g/mi (Federal Exhaust HC Emissions Standard for 1980 to present), with Al showing 1.4 to 6.6 times this limit and A2 showing 1.7 to 10 times the standard. The Tercel and Chevette with the Al disablement were the only two cases for which crankcase emissions did not surpass the 0.41 g/mi standard. In all cases, the A2 disablement produced higher HC emissions than the Al disablement. Excluding the Tercel and Chevette, the remaining seven vehicles produced from 5.5 to 73 percent more HC with A2 than with Al. The Tercel and Chevette emitted more than four times as much HC with A2 than with Al. Vehicles showing more than 50 percent HC increase from Al to A2 disablement were the Cougar (54 percent), Tercel (100 percent), Nova (56 percent), Delta 88 (73 percent) and Chevette ( 100 percent). The finding that the A2 disablement HC emissions are generally higher than those with the Al disablement is as might be expected, since blowby emissions should be more readily emitted from the crankcase through two open orifices on the valve cover rather than one. Results of crankcase on-line hydrocarbon emissions with PCV disablement configuration Al and A2 on the nine test vehicles are shown graphically in Figure 10. Although a correlation of HC emissions with odometer mileage or engine displacement is not easily discernable, the graph does show on closer study that the larger displacement engines (229 in.^and larger) produced most of the higher crankcase HC emissions. Engines in this displacement range all had HC emissions rates greater than 1.0 g/mi. Moreover, the Monte Carlo (229 in.3), Skyhawk (231 in.3),and Cougar (351 in.3) had HC emissions greater than 1.5 g/mi using both disablements. The Nova (250 in.3) and Delta 88 (403 in.3) also had HC levels greater than 1.5 g/mi, but only with the A2 disablement. The Cougar with the 351 in.3 engine displacement produced the highest HC emissions of the study, indicating 2.72 g/mi with Al disablement and 4.18 g/mi with A2 disablement. The smallest engine displacement studied in this 28 ------- 5r- to O •H U) cn W U 2 (IJ w a u Al Disablement A2 Disablement Vehicle Year Odometer, mi 32K Eng.Disp.,in. 89 Eng.Type L4 Figure 10. Crankcase on-line THC emissions of nine vehicles during 3-bag FTP with PCV disablement configurations Al and A2 ------- program, also produced the lowest Al and A2 disablement HC emissions overall. This engine in the Tercel, with an 89 in.^ displacement, produced crankcase HC emissions of 0.16 g/mi with Al disablement, and 0.71 g/mi with A2 disablement. The Chevette, with 98 in.3 displacement, had the second lowest (0.21 g/mi) HC emissions with the Al disablement, but also the highest (2.16 g/mi) HC emissions with the A2 disablement of the 89 to 134 in.^ engines. During this study, methylene chloride washings of the Teflon tube and 2- inch rigid tube sampling system were conducted after some of the 3-bag FTP crankcase emissions tests (the sampling system was also cleaned and dried prior to testing). The washings were concentrated in weighing vials and dried under nitrogen gas. Dried weights of the concentrate indicated that HC losses in the sampling system were insignificant, since they constituted only two percent or less of the respective crankcase emissions as determined during the 3-bag FTP. Some of the concentrates were oily in appearance. Crankcase HC emissions measured during individual cycles of the 3-bag FTP tests with the nine vehicles were summarized in Table 4. Illustrated in Figure 11 are the on-line HC results from Table 4, taken during the cold transient, cold stabilized, and hot transient cycles using the A2 disablement configuration of the PCV system. The data clearly indicate that the cold transient and cold stabilized cycles, respectively, showed the lowest and highest HC levels for each vehicles throughout the study. Not only did the three cycles emit HC in a regular pattern, but they also showed a consistent relationship of HC levels between them on each vehicle. This relationship is more clearly demonstrated by listing the ratio of the cold stabilized and hot transient HC emissions to cold transient HC emissions for each vehicle, as summarized below: Ratio of Cold Stabilized HC Ratio of Hot Transient HC Vehicle to Cold Transient HC to Cold Transient HC Monte Carlo 3.2 2.2 Cougar 3.6 2.4 Tercel 2.9 1.9 Nova 2.6 1.9 Skyhawk 3.4 2.1 Delta 88 2.8 1.9 Aries 3.6 2.5 Celica 3.3 2.4 Chevette 3.8 2.1 Avg. 3.2 2.2 Std. Dev. 0.41 0.24 30 ------- U) tn to C o •H w 0) •H g W U 0) to c (0 )-l U 5.51 g/mi Vehicle Year Odometer, mi Eng.Disp.,in. Eng.Type Tercel 1982 32K 89 L4 Chevette 1978 44K 98 L4 Aries 1983 21K 134 L4 Celica 1978 52K 134 L4 Monte Carlo 1982 2 IK 229 V6 Skyhawk 1977 57K 231 V6 Nova 1975 58K 250 L6 Cougar 1978 46K 351 V8 Delta 88 1978 69K 403 V8 Figure 11. Crankcase on-line THC emissions of nine vehicles during individual cycles of 3-bag FTP with PCV disablement configuration A2 ------- The ratio of cold stabilized HC to cold transient HC for the nine cars ranged from 2.6 (Nova) to 3.8 (Chevette), with an average of 3.2 and standard deviation of 0.41. Similarly, ratios of the hot transient HC to cold transient HC varied from 1.9 (Tercel, Nova, and Delta 88) to 2.5 (Aries), and averaged 2.2 with a standard deviation of 0.24. The essentially fixed ratios observed between the HC levels of the individual cycles of the FTP appear not to be functions of engine displacement or engine type or odometer reading, but rather of the combined effect of cycle type and crankcase oil temperature. During the cold transient cycle, the crankcase oil temperature apparently does not increase sufficiently to drive condensed fuel out of the oil and permit HC vapor augmentation of blowby gases. Under this condition, the oil temperature is also cool enough to allow some of the blowby being generated to condense. By contrast, the oil during the cold stabilized cycle is hot enough to both limit blowby condensation and to also degas more efficiently, thus allowing increased HC vapor contribution to the blowby gases. After the 10-minute soak, the scenario described for the cold stabilized cycle is repeated with the hot transient cycle; but this time at a higher oil temperature. E. Crankcase HC Emissions During Soak The on-line crankcase HC emissions obtained during the 10-minute soak following the cold stabilized cycle were summarized in Table 4, separately from the 3-bag FTP emissions results. The soak cycle is different from the 3-bag FTP individual cycles because it is run with the engine off. Consequently, units for the HC emissions during soak are g/min and not g/mi, as used with the 3-bag FTP. Results of the crankcase emissions during soak, using the Al and A2 disablements, are shown graphically in Figure 12. The HC emissions during the 10-minute soak generally diminished from those at the end of the cold stabilized cycle, to levels close to tunnel background. Generally, the major part of the HC emissions reduction occurred within the first three minutes of the soak. The highest soak HC emitters using the Al configuration were the Chevette at 0.29 g/min and the Cougar at 0.28 g/min. Highest HC emitters with the A2 configuration were the Cougar and Skyhawk at 0.19 g/min. Generally, the A2 disablement provided lower soak HC emissions. The Aries and Skyhawk were the only cases for which A2 emissions were higher than Al emissions. The vehicles with A2 disablement soak emissions less than half those for the Al disablement were the Chevette, Celica, Monte Carlo, Nova, and Delta 88. 32 ------- OJ OJ 01 c o •H [fl W •H 0) en o 1 u Al Disablement A2 Disablement 0.0 Vehicle Tercel Year 1982 Odometer, mi 32K Eng.Disp.,in. 89 Eng.Type L4 Chevette 1978 44K 98 L4 Aries 1983 21K 134 L4 Celica 1978 52K 134 L4 Monte Carlo 1982 21K 229 V6 Skyhawk 1977 57K 231 V6 Nova 1975 58K 250 L6 Cougar 1978 46K 351 V8 Delta 88 1978 69K 403 V8 Figure 12. Crankcase on-line THC emissions of nine test vehicles during 10-minute soak of 3-bag FTP with PCV disablement configurations Al and A2 ------- REFERENCES 1. Walz, L., "Motor Vehicle Tampering Survey 1982," EPA-330/1-83-001, April 1983. 2. Code of Federal Regulations, Title 40, Chapter 1, Part 86, Sub part B. 3. "Methane Measurement Using Gas Chromatography-SAE J1151," Recommended Practice SAE J1151, 1977. 4. Urban, C.M., "Unregulated Exhaust Emissions from Non-Catalyst Baseline Cars Under Malfunction Conditions," Final Report prepared for the Environmental Protection Agency under Contract 68-03-2884, Task Specifications 4 and 5, May 1981. 34 ------- APPENDIX A WORK ASSIGNMENT NO. 19 SCOPE OF WORK AND MODIFICATIONS ------- Scope of Work Work Assignment No. 19 to EPA Contract 68-03-3162 "Crankcase Emissions with Disabled PCV Systems" Introduction This work assignment is intended to quantify crankcase emissions from gasoline powered passenger vehicles with disabled PCV systems. PCV systems have been found to be disabled with the PCV valve disconnected from its orifice in the valve cover and/or with the fresh air tube to the air cleaner disconnected. This test program will initially test vehicles in two ways: with only the PCV valve disconnected, and with both the PCV valve and fresh air hose disconnected. It is believed that the fresh air hose being disconnected without the PCV valve being disconnected will not cause an emissions change. In-use vehicles of various engine sizes and model years will be recruited and tested by the contractor. Crankcase emissions will be measured over the- FTP cycle through a modified CVS to yield emissions in grams per mile. Emissions will also be measured during the 10 minute hot soak of the FTP, in a separate bag. A heated FID will additionally sample emissions during testing in order to ensure that all HC emissions are accounted for. Methane analysis will also be performed. Test Apparatus Crankcase emissions shall be measured through a CVS. A system shall be fabricated by the contractor which will attach to the normal PCV orifice which receives the crankcase emissions. This system shall be made such that it can draw fresh air through it, thus not creating an unrealistic vacuum. The vacuum shall be measured as close to the PCV orifice as possible within this system and maintained at 0.0-0.5 inches of water with the engine off and the CVS on. The PCV valve shall remain attached to its hose going to the carburetor or manifold and be outside of the fabricated system. A heated FID shall measure HC emissions and methane analysis shall be performed. Vehicles The contractor shall obtain test vehicles from any source. \ broad mix of vehicle types is required. The contractor shall obtain approval of the vehicle selection by the BTR prior to testing. Requirements are listed below. A-2 ------- -2- 1. Ten test vehicles, with no two vehicles identical in make and engine size. 2. Odometers shall be between 20-60K miles for all vehicles with an average of 40K miles. 3. Four to five vehicles shall be 1981 or later model year. The others shall be 1975-1980 model year. 4. Two vehicles each shall have engine sizes in the following categories: a. Less than 1.7 liters. b. 1.8-2.5 liters. c. 2.6-3.9 liters. d. 4.0-5.6 liters. e. greater than 5.7 liters. Test Conditions In both conditions listed below, the PCV valve will be disconnected from its orifice which receives crankcase emissions and be left connected to its hose going to the carburetor or manifold. 1. PCV disconnected, but fresh air hose to air cleaner remains connected. 2. PCV disconnected, and fresh air hose to air cleaner disconnected and plugged at the air cleaner end. Emissions Tests Each vehicle shall be tested once at each condition listed above. Only crankcase HC emissions shall be measured. 1. Four Bag FTP In addition to the normal three bags of the cold start FTP, crankcase emissions shall be collected and measured during the 10 minute soak period in a fourth bag. Emissions from the fourth bag shall be reported separately, i.e., not averaged in with the FTP. 2. Heated FID A heated FID shall sample emissions during all testing. 3. Methane Analysis Methane analysis is required for all testing. A-3 ------- -3- Option to Discontinue Testing After two vehicles have been tested, the contractor shall report the results verbally to the Branch Technical Representative. If crankcase emissions appear to be insignificant at either test condition, the BTR may delete a test condition from further testing or may end the test program altogether. A-4 ------- MAY 9 1984 Mr. Charles T. Hare Project Manager Southwest Research Institute P.O. Drawer 28510 6220 Culebra Road San Antonio, TX 78284 Re: Work Assignment No. 19 of Contract 68-03-3162 Dear Mr. Hare: The purpose of this letter is to provide technical direction to Work Assignment No. 19, titled "Crankcase Emissions with Disabled PCV Systems". We have determined that there are two disablement modes that could possibly cause crankcase emissions, other than the two listed in the Scope of Work. Please add these two disablement configurations to the other two. Also, we would like to revise the second of the original modes (see below). As before, we may delete one or more of the configurations, depending on the results of the first two or three vehicles. The two new configurations are listed below aftet the two original ones. Revised Disablement Configurations To Employ A. PCV valve disconnected from its orifice which receives crankcase emissions, and still connected to its hose going to carburetor or manifold. 1. PCV disconnected; fresh air hose to air cleaner connected. 2. PCV disconnected; fresh air hose to air cleaner completely removed and no part of the system plugged [this is a change]. B. New disablements 3. PCV valve remains connected in orifice, but disconnected from hose going to carburetor or manifold; fresh air hose system intact. A-5 ------- -2- 4. Fresh air hose to air cleaner completely removed; PCV system properly connected. These changes are a reemphasis of the effort, but are not an increase to the scope of the program. Adjustments may have to be made in other areas, such as the total number of vehicles, in order to maintain the overall effort. After the first two or three vehicles have been tested, please contact me for review of the effort required. All other parts of the Scope of Work shall remain the same. If you have any questions, please call. .Sincerely yo Robert Garbe, Project Officer Technical Support Staff cc: James Bzdusek, Contracts A-6 ------- APPENDIX B LIST OF AVAILABLE TEST VEHICLES AS OF JULY, 1984 ------- SOUTHWEST RES EARCH INSTITUTE INTERDEPARTMENTAL MEMORANDUM TO: SwRl and SFBR Staff t* FROM: Daniel A. Montalvo - Dept. of Emissions Research SUBJECT: Crankcase Gas Emissions Tests Using Gasoline Vehicles DATE: June 20, 1984 We need to measure crankcase gas emissions from gasoline passenger vehicles driven from 20,000 to 60,000 miles using only unleaded gasoline. Model years from 1975 to present are required in the following engine catagories: a. less than 1.7 liters (<104 cu. in.) b. 1.8-2.5 liters (110-153 cu. in.) c. 2.6 - 3.9 liters (159-238 cu. in.) d. 4.0-5.6 liters (244-342 cu. in.) e. greater than 5.7 liters (>348 cu. in.) The test will require approximately five (5) days. If your car is used, you will be given $75.00, and will also be furnished a car for transportation during its use. Your car will be returned to you with a full tank of gasoline at completion of testing. If you are willing to participate, please fill in the form and return it to Daniel Montalvo at Building 87. Any questions concerning this request may be directed to Daniel Montalvo at extension 2657. Yes, I would like to participate in the crankcase gas emissions tests to be conducted at the Department of Emissions Research. My car has _ actual miles on the odometer and, to the best of my knowledge, has run only on unleaded fuel. Make _ Model Engine Displacement . I/ cu. in. Cylinder No. and Type teS' Dept. Telephone No. B-2 ------- AVAILABLE TEST VEHICLES Less than 1.7 liters (<104 cu. in.) Year 1978 1978 1981 1981 1981 1981 1981 1981 1981 1981 1981 1981 1982 1982 1982 1982 Make Plymouth Chevrolet Toyota Ford Plymouth Plymouth Honda Toyota Chevrolet Dodge Mercury Honda Ford Honda Oatsun Toyota Engine Model Displacement, I Sapporo Chevette Tercel Escort TC3 Horizon Civic Tercel Chevette Colt Lynx Civic Escort Prelude Sentra Tercel 1.6 1.6 1.5 1.6 1.7 1.7 1.3 1.5 1.6 1.4 1.6 1.5 1.6 1.7 1.5 1.5 Cylinder No. 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 Odometer , Miles 39,000 43,600 39,120 58,000 70,200 58,731 46,000 26,400 27,426 38,000 46,599 67,000 34,372 25,300 40,000 31,867 1.8-2.5 liters (110-153 cu. in.) 1978 1978 1978 1979 1979 1980 1980 1980 1980 1980 1980 1980 Volvo Toyota Toyota Honda AMC Toyota Chevrolet Chevrolet Ford Honda Buick Mercury 244 DL Celica Celica Accord Spirit Celica GT Monza Monza Mustang II Accord LX Skyhawk Capri 2.1 2.2 2.2 1.8 2.0 2.2 2.5 2.0 2.3 1.8 2.5 2.3 4 4 4 4 4 4 4 4 4 4 4 4 45,000 51,320 44,000 92,787 45,873 52,093 41,239 58,260 31,000 43,467 56,100 41,000 B-3 ------- AVAILABLE TEST VEHICLES 1.8-2.5 liters (110-153 cu. in.) (Cont'd.) Year 1980 1981 1981 1981 1982 1982 1982 1982 1982 1982 1982 1982 1983 1983 1983 1983 Make Honda Olds. Honda Volkswagen Chevrolet Peugeot Dodge Mazda Toyota Toyota Toyota Chevrolet Oatsun Toyota Dodge Honda Engine Model Displacement, £ Accord Omega Accord Rabbit Cavalier 505 Charger 626 Corona Corolla Corolla Cavalier Maxima Corolla Aries Accord LX 1.8 2.5 1.8 1.7 1.8 2.0 2.2 2.0 2.2 1.8 1.8 1.3 2.4 1.8 2.2 1.8 Cylinder No. 4 4 4 4 4 4 4 4 4 4 4 4 6 4 4 4 Odometer, Miles 53,470 22,000 29,102 34,482 28,700 23,000 42,400 52,340 55,000 38,933 27,382 20,060 23,261 30,000 19,300 25,100 2.6-3.9 liters (159-238 cu. in.) 1977 Buick Skyhawk 3.3 1978 Pontiac Grand Prix 3.8 1978 Ford Fairmont 3.3 1978 Pontiac Sunbird 3.8 1980 Pontiac Grand Prix 3.8 1980 Ford Fairmont 3.3 1981 Dodge Challenger 2.6 1961 Dodge Challenger 2.6 1981 Ford Fairmont 3.3 1981 Pontiac Grand Prix 3.8 1981 Pontiac La Mans 3.8 1981 Chevrolet Monte Carlo 3.8 6 6 6 6 6 6 4 4 6 6 6 6 56,900 64,000 57,976 54,321 56,559 22,000 38,000 41,860 20,000 55,935 40,415 20,850 B-4 ------- AVAILABLE TEST VEHICLES 2.6-3.9 liters (159-238 cu. in.) (Cont'd.) Year 1981 1982 1982 1982 1983 1983 Make Mercury Pontiac Plymouth Chevrolet Oldsmobile Toyota Engine Model Displacement,?, Zephyr Bonneville Gran Fury Celebrity Cutlass Sup. Cressida 3.3 3.8 3.7 2.8 3.8 2.8 Cylinder No. 6 6 6 6 6 6 Odometer, Miles 27,788 22,808 21,200 34,310 22,097 31,163 4.0-5.6 liters (244-343 cu. in.) 1975 1975 1977 1978 1978 1978 1978 1978 1978 1978 1979 1979 1979 1981 1982 1982 1982 Chevrolet Chevrolet Chevrolet Mercury Pontiac Pontiac Pontiac Pontiac Chevrolet Pontiac Oldsmobile AMC Ford Pontiac Oldsmobile Oldsmobile Chevrolet Nova Nova Impala Zephyr Grand AM Phoenix Grand Prix Grand Prix Malibu Firebird Salon DL LTD Catalina Cutlass Delta 88 Monte Carlo 4.1 4.5 5.0 5.0 4.9 5.0 5.0 4.9 5.0 5.0 4.3 4.2 5.0 5.0 4.3 5.0 4.4 1983 Oldsmobile Custom Cruiser 5.0 6 8 8 3 8 8 3 3 3 8 3 6 3 8 8 8 8 8 57,700 52,200 88,000 56,538 61,321 60,000 51,800 44,778 42,000 65,000 61,668 33,222 56,216 26,850 39,800 36,243 34,640 23,645 B-5 ------- AVAILABLE TEST VEHICLES Greater than 5.7 liters (>348 cu. in.) Year Make 1975 Pontiac 1976 Oldsmobile 1976 Chevrolet 1977 Chevrolet 1977 Mercury 1978 Mercury 1978 Oldsmobile 1978 Chevrolet 1978 Cadillac 1979 Oldsmobile Engine Model Displacement,. Gran Prix 7.5 Delta 88 7.5 Monte Carlo 5.7 Camaro 5.7 Grand Marquis 7.5 Cougar 5.8 Delta 88 6.6 Caprice 5.7 Sedan Deville 7.0 Delta 88 5.7 Cylinder No. 3 8 8 8 3 3 8 8 3 Odometer, Miles 135,000 114,777 60,000 102,000 65,000 44,820 63,000 45,000 59,432 66,315 B-6 ------- TECHNICAL REPORT DATA (Please read Instructions on the reverse before completing) 1. REPORT NO. EPA 460/3/84/011 2. 4. TITLE AND SUBTITLE CRANKCASE EMISSIONS WITH DISABLED PCV SYSTEMS 7. AUTHOR(S) Daniel A. Montalvo Charles T. Hare 9. PERFORMING ORG '\NIZATION NAME AND ADDRESS Southwest Research Institute Department of Emissions Research 6220 Culebra Road San Antonio, Texas 78284 12. SPONSORING AGENCY NAME AND ADDRESS Environmental Prote ction Agency 2565 Plymouth Road Ann Arbor, Michigan 48105 15. SUPPLEMENTARY NOTES 3. RECIPIENT'S ACCESSION- NO. 5. REPORT DATE March 1985 6. PERFORMING ORGANIZATION CODE 8. PERFORMING ORGANIZATION REPORT NO. 10. PROGRAM ELEMENT NO. 11. CONTRACT/GRANT NO. 68-03-3162 13. TYPE OF REPORT AND PERIOD COVERED Final Report (5/1985-9/1984) 14. SPONSORING AGENCY CODE 16. ABSTRACT This report describes the laboratory testing of nine in-use light-duty gasoline passenger cars using up to four PCV disablement configurations. The nine vehicles included 1975 to 1983 model years, with odometer readings generally between 20,000 and 60,000 miles. No two vehicles were identical in make and engine type, and engine displacements ranged from 89 to 403 in. 3. The vehicles were tested over the 1975 Federal Test Procedure, with sampling for crankcase HC conducted during each individual cycle of the 3-bag FTP and during the 10-minute hot soak. Emissions of crankcase HC are provided in g/mi for the 3-bag FTP, and in g/min for the 10-minute soak. 17. a. DESCRIPTORS Blowby Crankcase PCV Disabled PCV Gasoline Engine 13. DISTRIBUTION STATEMENT Release Unlimited KEY WORDS AND DOCUMENT ANALYSIS b-IDENTIFI Gasol Crank Crank Light Cra 19. SECURI Uncla 20. SECURI Uncla ERS/OPEN ENDED TERMS C. COS AT I Field/Group ine Engine PCV System case HC Emissions case Blowby -Duty Vehicle nkcase Emissions TY CLASS (This Report) 21. NO. OF PAGES ssified 53 TY CLASS (This page) 22. PRICE ssif ied EPA Form 2220-1 (9-73) ------- INSTRUCTIONS 1. REPORT NUMBER Insert the EPA report number as it appears on the cover of the publication. 2. LEAVE BLANK 3. RECIPIENTS ACCESSION NUMBER Reserved for use by each report recipient. 4. TITLE AND SUBTITLE Title should indicate clearly and briefly the subject coverage of the report, and be displayed prominently. Set subtitle, if used, in smaller type or otherwise subordinate it to main title. When a report is prepared in more than one volume, repeat the primary title, add volume number and include subtitle for the specific title. 5. REPORT DATE Each report shall carry a date indicating at least month and year. Indicate the basis on which it was selected (e.g., date of issue, date of approve!, date of preparation, etc.). 6. PERFORMING ORGANIZATION CODE Leave blank. 7. AUTHOR(S) Give name(s) in conventional order (John R. Doe, J. Robert Doe, etc.). List author's affiliation if it differs from the performing organi- zation. 8. PERFORMING ORGANIZATION REPORT NUMBER Insert if performing organization wishes to assign this number. 9. PERFORMING ORGANIZATION NAME AND ADDRESS Give name, street, city, state, and ZIP code. List no more than two levels of an organizational hirearchy. 10. PROGRAM ELEMENT NUMBER Use the program element number under which the report was prepared. Subordinate numbers may be included in parentheses. 11. CONTRACT/GRANTNUMBER Insert contract or grant number under which report was prepared. 12. SPONSORING AGENCY NAME AND ADDRESS Include ZIP code. 13. TYPE OF REPORT AND PERIOD COVERED Indicate interim final, etc., and if applicable, dates covered. 14. SPONSORING AGENCY CODE Leave blank. 15. SUPPLEMENTARY NOTES Enter information not included elsewhere but useful, such as: Prepared in cooperation with, Translation of, Presented at conference of, To be published in, Supersedes, Supplements, etc. 16. ABSTRACT Include a brief (200 words or less) factual summary of the most significant information contained in the report. If the report contains a significant bibliography or literature survey, mention it here. 17. KEY WORDS AND DOCUMENT ANALYSIS (a) DESCRIPTORS - Select from the Thesaurus of Engineering and Scientific Terms the proper authorized terms that identify the major concept of the research and are sufficiently specific and precise to be used as index entries for cataloging. (b) IDENTIFIERS AND OPEN-ENDED TERMS - Use identifiers for project names, code names, equipment designators, etc. Use open- ended terms written in descriptor form for those subjects for which no descriptor exists. (c) COSATI FIELD GROUP - Field and group assignments are to be taken from the 1965 COSATI Subject Category List. Since the ma- jority of documents are multidisciplinary in nature, the Primary Field/Group assignment(s) will be specific discipline, area of human endeavor, or type of physical object. The application(s) will be cross-referenced with secondary Field/Group assignments that will follow the primary posting(s). 18. DISTRIBUTION STATEMENT Denote releasability to the public or limitation for reasons other than security for example "Release Unlimited." Cite any availability to the public, with address and price. 19. & 20. SECURITY CLASSIFICATION DO NOT submit classified reports to the National Technical Information service. 21. NUMBER OF PAGES Insert the total number of pages, including this one and unnumbered pages, but exclude distribution list, if any. 22. PRICE Insert the price set by the National Technical Information Service or the Government Printing Office, if known. EPA Form 2220-1 (9-73) (Reverse) ------- |