72-22 EVALUATION OF THE LANDRUM RETROFIT SYSTEM April 1972 Henry L. Gompf Test and Evaluation Branch Environmental Protection Agency ------- Background Mr. Porter Landrum of Birmingham, Alabama, supplied the Test and Evaluation Branch with test data indicating significant reduction in hydrocarbon and carbon monoxide on a vehicle equipped with his retrofit system. Based on this preliminary testing, a confirmatory evaluation was conducted in the EPA laboratory at Ann Arbor. Device Tested The Landrum system employs the replacement of stock idle mixture screws with hollow bleed-type screws. These screws are tranversely drilled near the ends to allow gasoline to enter mixing with air. The air supplied to the screws is preheated by means of a vacuum actuated cylindrical resistance heater. For this test the stock idle screws were removed from a 1971 Ford, 351 CID engine with automatic transmission. Mr. Landrum's screws were installed with the associated heating element. No idle mixture adjustment was necessary as the Landrum screivs are seated solidly in the carburetor. Test Program Testing of the vehicle, both baseline and device equipped was done in accordance with the November 10, 1970, and July 2, 1971, Federal Register. These documents describe the 1972 and 1975 Federal Test Procedures, respectively. In addition, fuel consumption has been calculated from the exhaust emissions for each test. • Test Results The test data is presented in the Appendix of this report. As indicated the Landrum system appears to reduce hydrocarbon by 101 and carbon monoxide by 15%. A 71 fuel consumption penalty is associated with the system. It should be noted that the baseline vehicle, in this case, was set at a lean idle of .251 CO. This was roughly the same idle CO level as obtained with the Landrum device installed. ------- -2- Conclusions While the reductions obtained appear .small, this was partially due to careful adjustment of the baseline vehicle to a lean idle setting. The setting for the Landrum system required merely the seating of the special idle screws. No doubt the effective reduction of carbon monoxide would have been appreciably higher if the test vehicle had been adjusted to normal maintenance levels of carbon monoxide. Due to the use of small passages in the idle screw concern is expressed over deposit plugging. This tendency could result in rough idle, stalling, or misfire. Durability testing would be required to quantitatively evaluate this condition. ------- -3- APPENDIX • 1975 Federal Emission Test All Emission Results in Grams Per Mile Date HC CO Baseline 4 4 -17-72 -18-72 Average Landrum Sys 4 4 4 4 -4-72 -5-72 -6-72 -7-72 Average 2. 2. 2. tern 2. 2. 2. 2. 2. 81 44 63 46 28 42 29 36 13. 11. 12. 12. 11. 10. 9. 10. 9 0 5 0 0 2 3 6 co2 644. 651. 647. 690. 732. 724. 690. 709. NOx 1 4 8 4 3 9 7 6 5. 5. 5. 6". 5. 5. 5. 5. 35 42 39 10 05 23 27 41 Fuel MPG 12. 12. 12. 12. 11. 11. 12. 11. 9 9 9 0 5 6 4 9 °o Reduction from Baseline iu% increase in 7% penalty ------- -4- 1972 Federal Emission Test All Results in Grams Per Mile Date Baseline 4-17-72 4 -18-72 Average HC 3.25 2 2 .68 .97 CO 24 19 21 .4 .2 .8 co2 677 678 678 NOx .9 .7 .3 5 5 5 .37 .27 .32 Landrum System 4 4 4 4 -4-72 -5-72 -6-72 -7-72 Average 2 2 2 2 2 .96 .61 .61 .51 .67 21 19 16 15 18 .0 .8 .6 .9 .3 720 760 776 710 741 .0 .0 .9 .1 .8 6 4 5 5 5 .13 .97 .10 .12 .33 % Reduction from Baseline 10% 161 9% increase 0% ------- |