1. 27-Jun-03030702 B&S ARB Workshop Comments Evaporative Emissions Control Technology – An Engine Manufacturer’s Perspective Two Threshold Design Issues: –Pressurized Fuel Systems? –Metal or Treated Plastic Tank? Implementation Issues: –Lead-time for new fuel systems –Equipment integration issues

2. 27-Jun-03030702 B&S ARB Workshop Comments Sealed Tank Systems Fuel Cap 1999 Mazda 626

3. 27-Jun-03030702 B&S ARB Workshop Comments Sealed Tank System Characteristics Tank Pressure Control Valve Pressurized fuel tank Tank Pressure-Vacuum Relief Mechanism Fuel lines and connectors

4. 27-Jun-03030702 B&S ARB Workshop Comments Tank Pressure Control Valves Require dual vent and fuel shut-off valves –Isolate of carburetor from high pressures –Sequential valve actuation – start and hot restart performance? Automatic valve actuation mechanism –Engine brake bail only on WBM –Blade-brake clutch solution? –Other application solution? Spatial relations or packaging limitations

5. 27-Jun-03030702 B&S ARB Workshop Comments WBM Fuel System Spatial Relationships Brake Fuel Tank Carburetor Briggs & Stratton Tecumseh

6. 27-Jun-03030702 B&S ARB Workshop Comments Tank Pressurization Concerns Fatigue failure consequences Crack sprays – increased risk for uncontrolled liquid fuel release if cracks occur Pressurized tanks will be less forgiving under impact conditions Tank deformation 5.0 psig spray

7. 27-Jun-03030702 B&S ARB Workshop Comments Tank Deformation Under Pressure

8. 27-Jun-03030702 B&S ARB Workshop Comments Residual Tank Deformation 5 Minutes After Pressure Relief

9. 27-Jun-03030702 B&S ARB Workshop Comments Tank Deformation at 3.0 psig

10. 27-Jun-03030702 B&S ARB Workshop Comments Tank Deformation at 5.0 psig

11. 27-Jun-03030702 B&S ARB Workshop Comments Automotive Fuel Tank Pressure-Vacuum Relief Cap

12. 27-Jun-03030702 B&S ARB Workshop Comments Pressure –Vacuum Relief Performance

13. 27-Jun-03030702 B&S ARB Workshop Comments Pressure Relief – 30 Part Population

14. 27-Jun-03030702 B&S ARB Workshop Comments Pressure Relief – After Soak

15. 27-Jun-03030702 B&S ARB Workshop Comments Pressure Relief – Umbrella Valves Data available Monday, 6/30. Will show cracking pressure in10 piece population before and after Cert fuel soak.

16. 27-Jun-03030702 B&S ARB Workshop Comments Pressure-Vacuum Relief Valves Summary Commercially available fuel system pressure-vacuum relief valves: –Not binary (leak before relief) –Relief pressures are inconsistent –Fuel exposure affects valve performance

17. 27-Jun-03030702 B&S ARB Workshop Comments Fuel Hose and Connection Reliability Summary Pressurized fuel systems will introduce stresses to fuel system connections –Reduced reliability –Fuel spray possible at failure –Gross-emitters –Operator Risk –Maintenance and Repair Risk

18. 27-Jun-03030702 B&S ARB Workshop Comments J2260 Tubing and Connectors

19. 27-Jun-03030702 B&S ARB Workshop Comments Packaging Constraints - Fuel Line WBM Engine – Line Routing and Interferences

20. 27-Jun-03030702 B&S ARB Workshop Comments Automotive Fuel Cap Warnings Subaru Forrester Dodge Neon Pontiac Montana Ford Ranger

21. 27-Jun-03030702 B&S ARB Workshop Comments Automotive Fuel Fill Neck

22. 27-Jun-03030702 B&S ARB Workshop Comments Small Off-Road Engine Fuel Fill Neck B&S 6.5 Hp Vertical Shaft

23. 27-Jun-03030702 B&S ARB Workshop Comments Small Off Road Engine Fuel Fill Neck B&S 8 hp Horizontal Shaft

24. 27-Jun-03030702 B&S ARB Workshop Comments Small Off-Road Engine Fuel Fill Neck M9/10

25. 27-Jun-03030702 B&S ARB Workshop Comments Vapor Release Management Challenges are more acute than those encountered in other industries –Short fill necks –Tight packaging –Thermal management of exhaust and catalyst –Angle of operation –Refueling

26. 27-Jun-03030702 B&S ARB Workshop Comments Evaporative Controls Testing Industry Capabilities