|
Again, respectfully, I'm just offering different thoughts as an outside observer. No one has yet been able to say how many engines have been affected so far, which is why it may not be statistically significant. No one has come up with a failure mechanism, just some hypotheses that may or may not be true. And, as far as I've read, there does not seem to be any rash of broken cylinder 3 rockers on other cars using the same engine.
The oil spray theory might be reasonable if you can prove that oil does not get deposited on some part of the #3 cam lobe. Since the cam is running in the boundary and mixed lubrication regime a steady stream of oil will deposit a boundary antiwear layer.
Another theory would be a problem with the cam hardening process for a certain batch, where for some reason lobe 3 was not hardened properly. This can be measured in a lab.
I'm still not seeing how the follower can crack and fail as it does, unless some significant back-force is placed on it from the valve. The only other possibility I can think of is that there was a total lubrication failure on the cam, which causes the follower to overheat and become brittle. If you want to know the failure mechanism, find a private metallurgist, and a tribologist, or ones at a university that you can befriend and have a forensic analysis done.
Y'all would be much better served if you fully documented all instances of failures or near-failures in one place, and presented a coherent case. It may be here amongst the threads, but I just don't see it. I'm all for using forums like these to pressure manufacturers, but not until the case is solid.
|