So I was thinking that my issues with the catch can filling rapidly with oil could have a couple of different causes
- not enough baffling making the valvetrain oil simply splash into the breather hose.
- not enough oil separation from removing the fine oil mist separator in the factory PCV setup.
- increased blow by from removing the manifold vacuum thus increasing crank case pressure which in turn could make the piston rings not seal as good.
- or the fact that the blow by flow is now routed through the valvetrain and that it might pick up oil droplets and carry them into the catch can.
This is how the underside of my adapter plate looked before I modified it:
Unmodified adapter plate.jpg
At fist I made an attempt to just limit the possibility of the oil splashing into the vent hole:
Modified PCV v1.PNG
Yes, I know the precision of the drilling is a bit more organic then what one could ask for
The intention was to let the blow by gases into the adapter plate in a much more baffled area. If you look at the valve cover it is already baffled in the area of the multiple small holes. I hoped that this would help to reduced oil splashing into the vent hole, but it did virtually no difference. I still had a 1/4 of my catch can full after going to work and back.
OK, back to the drawing board. I sat down and looked at the self study program again and this is what I came up with:
Modified PCV v2 5.PNGModified PCV v2 6.jpgModified PCV v2 7.PNGModified PCV v2 8.PNGModified PCV v2 9.jpg
The idea was to contain the blow-by gases withing the adapter plate and not the let it out into the valve train where it will introduce unnecessary water and fuel from the blow-by and limit the blow-by from picking up any oil droplets on the way. The area where the blow-by comes up from the block was partially capped of by my adapter plate, don't know what they were thinking by doing that, so that had to be ported out (top left corner of the first image). Top right corner I made room for a screw. And then to incorporate some kind of oil separation I am directing the flow into the volume where the fine oil mist separator used to be and the flow needs to do a 180 degree turn in order to flow back up again hopefully separating out some oil droplets. The blow-by then flows into the main chamber again and under the outlet passage and into the vent hole to the catch can. The passage under the outlet pipe is a bit narrow and there were a risk of oil collecting in the cut out there so I drilled a drain hole in the cover plate (should have made it smaller though).
After going to work and back today there were maybe 1/3 or 1/4 of the amount of oil I have had with the first version. It is still a bit much but it is substantially better than before.
To adjust it just a bit further I will probably try to seal off the transition from the blow-by passage in the cylinder head/valve cover into the adapter plate with an uncut OEM gasket and make the drain hole a bit smaller.
I don't believe that I have increased the crank case pressure that much further by doing it this way since the smallest passage right now is larger than in the factory PCV and about the same size as the outlet of the original adapter plate but I can be wrong, haven't measured.
I have an update / some questions on the tuning side as well but that will have to wait for now.
Cheers,
Alex