Hi Yall. I have a couple Q's about Crankcase Ventilation on the 300.. hopefully someone can shine a brighter light on my queries.. As far as I can figure I have two options for the fitment of my Oil Catch can. A. Fit the can by running the two front Tappet Cover hoses to a "Y" connector and the two pre-turbo intake ports to a "Y" connection then connect these two "Y's" to each port on the Catch Can. B. Run the two front tappet cover hoses directly to each port on the catch can and use an air filter on the top of the catch can for ventilation. Now my questions... A. Is it essential to have the catch can running to a source of vaccum (ie the pre-turbo intake pipes). I have been told that the suction from this setup helps the rings to seal under boost... is this fact or fiction as I can't see the theory behind it.. I really like the Air-Filter-On-Top-Of-Catchcan look.. but this isn't going to work if there NEEDS to be vaccum. B. Is enough ventilation for the crankcase vapours provided by the front two tappet cover ports.. I want to seal up the pcv's and the read tappet cover ports for aesthetics.. I know that most of this crosses the line in the sand for emissions laws but I have already bypassed most stuff anyway (EGR, AIV, under plenum cleanup etc).. so I know which side of the line I live on now anyway. My purpose behind all this is Engine Bay Dressup, Reduction of non-essential hoses etc (my theory for working on the 300 is the KISS method). and reduction/prevention of oily crap in my plenum... Thanks in advance to all participants of this Q&A.
These pic's might help! these pic's are minivans, im sure he wouldn't adding comment, if your stuck. Chilli also has a simlar setup maby he may care to comment!
Thanks beaver... Unfortunately these pics are actually only showing PCV's are running to a modified tappet output (not even sure why the modification was done - though I am sure if minivan and chilli have done it the reason must be sound).. I was hoping to bypass the PCV's all together and just use the front Tappet Cover Ventilation Ports to the catch can. Any answer to Question A. though.... that is the one that has me most troubled at the moment.... J
I think what you are considering is illegal. PCV's are the basis of emission control. EGR was dropped in later cars, I havn't figured out what AIV's really do, but Positive Crankcase Ventilation is a good thing. You can run a catch can with PCV's.(to catch all the oil that shouldnt be there anyway) The best solution to reducing oil and gunge in your plenum is replace the "seals" between the combustion chamber and crankcase (piston rings) or fix your leaky turbo's.
Well the pvc's are closed when your on boost, so there's no need to get rid off em at all, in fact without them preasure will build in the crankcase, and that usually causes the rear main seal to blow or frount main or any number off other problems. The place for the catch can is on the intake side, as the pvc valves are closed when boosting. Im sure others could explain it better than i could, so someone do it! im sleepy!
Re: Thanks to comments so far.... Baron.. my engine is in fine condition (seals and all appear ok) I mainly want to prevent any oily blow by when racing (ie.. High Revs). If the only reason one would want a catch can was because of worn rings or turbo seals... why do MANY race/drift cars use them (this was not a flame but a genuine question of need - please don't take as offence...) Beaver... from your post I take your answer as meaning the front tappet cover crankcase vents (left and right) do not adequately ventilate the crankcase pressure therefore all four (ie. rear and front) are definately required.. and if this is indeed the case.. if you leave the pcv's all connected up as they are from the factory (and as you suggest).. doesn't this defeat the purpose of the catch can as you will get blow-by oil through the PCV's anyway (you just won't get it from the front Tappet Cover Vents.).. I may very well be misinformed but all this leads me to believe that catch cans are absolutely useless on a 300 but I have seen many 300's sporting them...
Thats pretty much the case Most z owners only run the can through the pvc, to stop oil surge (Smoking) when hard corning on track days.It also hepls to keep the plenum and intercoolers clean from oily blow by gas.But when your on boost pvc"s are closed, so the engine is sucking the crankcase gasses and all the stuff you dont want, straight into the plenum for a reburn. that is why, if your keen,you do something on the inlet side. And yes i have a can plumbed through the pvc, and it dose F/A, for every day driveing, on the track yes. but remember its still usless untill you back off.
Re: Ok... So to straighten my train of thought once and for all... the front tappet cover crankcase ventilation ports (2) (Under throttle bodies) are insufficient for venting crankcase vapours and therefore all four (ie. ones under throttlebodies AND the rear ones for the PCV's) MUST be used... Sorry to sound dense but it just dumbfounds me that all four are needed for venting pressure in the crankcase...
You need the front ones to vent pressure (although to be more accurate the air is sucked out) because when you are under boost the PCVs close, and the excess air built up in the crank case has to go somewhere.
