Forum Discussion
BenK
Mar 28, 2012Explorer
Now thinking all CP3 and CP4 pumps hammer the follower and piston bottom and
from the metering valve shutting off the inlet to the cylinder head
This sets itself up for failure when at such time a sequence or maybe just one
event happens...or often enough
Now ask what is the RPM range of the little diesels in those 'cars' ?
Goes back to these basic issues that then stack up to the event(s) mentioned
at the end of this
That is all going on all the time. The higher the RPMs the more so
or worse it can get to be till....
Till one of those cavitation events dislodges some debris into that
too small and poorly lubed/flushed/etc cam area...where there is extreme
PSI between the cam face that follower roller...some debris gets into
that contact area to have the roller mash it into the DLC coated cam
face.
Maybe not a failure that instant, but surely soon after at another event...
Now the ambient conditions and the seemly association with failure
Wonder which of the above is affected by raising ambient conditions?
Then wonder why CP3's don't seem to have as many failures? That part
does not jive...or is the differences in the pump the key?
from the metering valve shutting off the inlet to the cylinder head
This sets itself up for failure when at such time a sequence or maybe just one
event happens...or often enough
Now ask what is the RPM range of the little diesels in those 'cars' ?
Goes back to these basic issues that then stack up to the event(s) mentioned
at the end of this
- Poor lube quality of the fuel
- Poor cooling of that cavity
- Re-cycling of that poor lube
- Small cavity so that there is no buffer capacity
- Extreme PSI at the contact patch of the follower/roller and the cam
- DLC to solve (didn't) that extreme PSI
- Organic amines attacking the DLC...bet higher heat makes it more reactive
- Hammering of the piston bottom and follower to create debris
- H2O intrusion via contaminated fuel not filtered out by both membrane filter and separator and/or emulsification
- Suspect cam shaft bearing's ability to keep H2O out during a cavitation event
- metering valve shuts during decel and/or EB to create cavitation potentials
- Potential mis-alignment between the cam and follower roller, made more so during any cavitation or vacuum event in that too small cavity
That is all going on all the time. The higher the RPMs the more so
or worse it can get to be till....
Till one of those cavitation events dislodges some debris into that
too small and poorly lubed/flushed/etc cam area...where there is extreme
PSI between the cam face that follower roller...some debris gets into
that contact area to have the roller mash it into the DLC coated cam
face.
Maybe not a failure that instant, but surely soon after at another event...
Now the ambient conditions and the seemly association with failure
Wonder which of the above is affected by raising ambient conditions?
Then wonder why CP3's don't seem to have as many failures? That part
does not jive...or is the differences in the pump the key?
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