JACTest Monitoring Center T-10 PB Ad Hoc Task Force Report to the Mack Test Surveillance Panel September 10, 2004 Richmond, VA
JACTest Monitoring Center T-10 PB History T-10 Test Developed on conrod bearings with a flash coat design of 80% Pb / 20% Sn SEP ’02 –Mack announces design change for production bearings –100 % Sn flash –Approximately 90 engine builds in stock at TEI
JACTest Monitoring Center T-10 PB History NOV ’02 –MSP votes to introduce 100% Sn flash conrod bearings at next reference test MAR ’03 –Reference test on 100% Sn flash bearings produces 6 ppm Pb. Target ~ 25 ppm. APR ’03 –MSP votes to obtain 200 build batch of bearings made to original design. –Reference extensions begin.
JACTest Monitoring Center T-10 PB History AUG – NOV ’03 –Five tests on new batch of 80/20 Pb/Sn Results – 9, 12, 12, 12, 16 ppm Pb Two tests invalid (9, 12) –MSP votes to run tests on unflashed bearings. NOV – DEC ’03 –Three tests run on unflashed bearings Results – 6, 8, 26 ppm Pb –MSP votes to obtain six sets of 100% Pb flash bearings
JACTest Monitoring Center T-10 PB History JAN – FEB ’04 –Three tests run on 100% Pb flash bearings Results – 8, 12, 26 ppm Pb MAR ’04 –MSP votes to obtain unflashed rod and main bearings
JACTest Monitoring Center T-10 PB History JUN – JUL ’04 –Three tests run on unflashed rod and main bearings Results – 7, 9, 27 ppm Pb –MSP forms Ad Hoc Task Force Investigate variability in Pb results Propose a path forward
JACTest Monitoring Center T-10 Ad Hoc Task Force Met three times in August –August 18 th in San Antonio –August 24 th via conference call –August 31 st via conference call Reviewed operational data and test results Discussed possible options to resolve problem
JACTest Monitoring Center T-10 Ad Hoc Task Force Conclusions Operational differences were found –Test to test –No one lab found to be consistently different –No ‘smoking gun’ found to explain variability Stage 1 Exhaust CO 2 on experimental bearing tests –dropped throughout the industry –produces slightly higher EGR flow rates –cause not found; further investigation necessary
JACTest Monitoring Center T-10 Ad Hoc Task Force Conclusions Ring and liner wear –variability may indicate test is having other problems Experimental bearing tests on Pb –break later –break harder
JACTest Monitoring Center T-10 Ad Hoc Task Force Actions Investigate –Cause of CO 2 shift –Fuel batch effects –Build oil effects –Availability of PC-9J Develop proposed solution –Correction factors –Use bearing weight loss or delta ir –Combination of the two
JACTest Monitoring Center T-10 Ad Hoc Task Force General Comments Any Proposed Solution –Likely to be less than ideal –Learn to live with solution or accept the death of the test T-12 Development –Should consider all possible options for oxidation Bearing weight loss (total, main and rod)
JACTest Monitoring Center T-10 Ad Hoc Task Force Proposed Solution Bearing Batch –Use the batch made to the original 80/20 Pb/Sn design. –Test data and results on these bearings appear to be better behaved than the other experimental bearings. –Added benefit of having ~ 190 test builds in stock
JACTest Monitoring Center T-10 Ad Hoc Task Force Proposed Solution Use Correction Factors to adjust back to original severity level