RJM wrote:
If there is nothing in the can its effectiveness will be minimal, I tried it and it still spews oil into the intake. May work well for a gasser but a diesel is an air hog, even at idle, The amount of blow-by is much greater on a diesel as well. The physics applied to the gasser world are not quite the same as a diesel. Nature of the beast.
I have put similar catch-cans on gassers that flowed significantly more air than a little 2.8L TD could ever hope to..... forced induction or not.
Even an empty chamber will work by causing a rapid decompression of the air causes the water and oil being carried in vapor form, to condense and fall to the chamber at the bottom of the can. The introduction of a filtration substrate only increases the surface area for condensation to occur, thereby "scrubbing" the air better.
There is no reason to have a pop-off valve on a catch can, unless that can can not withstand the even mild pressures found in a turbocharged system. I know the Provent is plastic, but I would hope they designed the can to withstand above normal boost pressures.
When properly installed the catch can will be most effective at idle, or near idle, when vac pressures are highest. Any time you are boosting the system, the PCV will slam shut to prevent the pressurization of the crankcase through the valve cover.
I would think that even in a Diesel, excessive blow-by would denote a failed seal somewhere in the rings, valves, or valve guides causing an overpressurization of the oiling system. Please correct me if I am wrong, but isn't excessive blow-by a BAD thing?
edited for clarity