| confirmed any of them either. All I know at this moment is that it wiped out the bearing on #4. I'm not trying to be a smartass here either bro, so dont get me wrong. From this moment, here is what I have to work with. The bearing failed.
There was an overboost issue on the passenger turbo a few thousand miles ago. This turbo feeds the driver's bank of cylinders, which is where the bearing failure occurred. This will cause the driver's bank to run an unknown degree leaner due to his intake type at the time of the failure (he had the JWT DP). I replaced the turbos and the car was run for a couple thousand miles or so since the new turbo install. No abnormal engine noises. It wasn't run hard as we were still awaiting final tuning. It didn't appear that the turbo failure affected the engine at all. Compression numbers were good and consistent across the board. I was up there just a couple months ago to do Rob Dawkins car and Dee's car was running just fine at that time. I drove it a few times during that stay. When I arrived this last trip and drove Dee's car, I noted the downpipe failure as well as the tapping noise. It seems to me that this failure has occurred within the last two months, but the car hasn't been pushed excessively by Dee. He had an aluminum flywheel installed recently and commented that the car was behaving abnormally from that time onward. Not sure if the shop that did the work may have taken the car out and raped it. :-/ When I get back up there, I will run a few more tests to see if there is an injector issue on that cylinder. I would like to know what others think of this assumption I have though. I consider that the crank journal, at this moment in time, is pretty much identical to what it was when the engine was originally assembled. Fortunately we caught it early enough that it didn't goober up the journal. I am thinking that once we put some more miles on the car, if there is an issue with the bearing again, we could say with greater confidence that the journal itself is likely out of round, or the chamfering done to the galley is excessive. I did note that the other journals weren't chamfered as much as this one and the bearing wear has a pattern to it that is interesting in light of the galley chamfering. There are so many possibilities for the failure, and all of the ideas have conflicting logic with each other. This is definately one that stumps me given what we have to work with at the moment, so I am all ears in terms of suggestions. My reponse to Ric was an attempt to get him to elaborate on what he thinks in the event that I haven't already considered what he meant. Time will tell though - I think there is just too little information at the moment to make a good conclusion on. I think it is one of the following: (listed in heirarchial order) 1) Defective injector
2) Journal #4 wasn't micropolished after chamfering (accidental oversight)
3) Journal #4 is out of round and causing accelerated wear on the bearing (regrinding error)
4) Shop that did the flywheel abused the car There are obviously many more possibilities, but in my mind at the moment, these appear to be the ones of greatest probability.
[ ashspecz.com ]
[ agpowers@bellsouth.net ] Enthusiasts soon understand each other. --W. Irving.
Are you an enthusiast? If you are out to describe the truth, leave elegance to the tailor.
Albert Einstein
|
