Comp R Lifters Fail (Pics) What would cause this?
06-18-2004, 04:40 PM
#21
You rarely see more than one rod or pair fail on an engine, given it kinda stops running after that. 
Not sure what condition 7/8 bearings were in when he disassembled the engine, that will likely tell the story of whether it was oil starvation or a localized blockage (metal got into the #3 crank main and passed downstream to the 5/6 rod journal.)
Interesting data point: Bondurant lost several engines on their school's C5 Vettes initially with the same failure mode, #4 rod bearing. Not 7/8, just 4. Upping to 15W-50 and overfilling resulted in no further blown engines. Go figure.
Not sure what condition 7/8 bearings were in when he disassembled the engine, that will likely tell the story of whether it was oil starvation or a localized blockage (metal got into the #3 crank main and passed downstream to the 5/6 rod journal.)
Interesting data point: Bondurant lost several engines on their school's C5 Vettes initially with the same failure mode, #4 rod bearing. Not 7/8, just 4. Upping to 15W-50 and overfilling resulted in no further blown engines. Go figure.
