PCV system theory and Oil catch cans.
#196
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is an oil catch can even necessary in a new car , or is it something to install later (after 30k miles or something?)
i have an 09 lancer ralliart which is 90% of the time under boost, not vaccum. (boost kicks in at 2500 and is preety strong until 4500rpms, so im usually under boost)
I just wonder because it doesnt come from the factory, so I wonder if its unecessary (like a turbo timer) thanks.
- alphawav
i have an 09 lancer ralliart which is 90% of the time under boost, not vaccum. (boost kicks in at 2500 and is preety strong until 4500rpms, so im usually under boost)
I just wonder because it doesnt come from the factory, so I wonder if its unecessary (like a turbo timer) thanks.
- alphawav
#197
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How often do you change your oil and what is your average trip length? Does the car get hot enough to burn off condensation? How much boost are you talking about?
And yes it is unnecessary for most people.
And yes it is unnecessary for most people.
#198
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thanks for your reply.. I havent changed the oil yet but I figure will change it 4k miles. Mobil 1 synth. Average trip lenght varies but, mostly about 10~20 miles. No, never seen the digital temp meter more than over 1/3 (a little bit more maybe, but not half) Boost, well factory boost , which doesnt press over 15psi I'm preety sure on the 2009 Ralliart beter install a boost gauge
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The catch can won't fix the oil consumptions issue. It will catch any blow-by that would head into the intake tract. Built motors will consume more oil depending on how they're built. If the tolerances are a bit loose, then you'll get more blow-by. If it's tight, it may just use more.
How long has it been in there/broken in?
How long has it been in there/broken in?
#205
Has anyone here tried the (MCCVK) krank vent mini version? I ordered this from speed circuit and i just got it today. Unlike the catch cans ,which only treat the symptoms, these krank vents are supposed to keep any of this from happeneing in the first place.(the cure)!!It costs 119.99 and goes in the same spots as you would put catch cans.They say increases engine effiency,piston ring seal,performance and lowers emissions. they look like 2 pcv valves on steriods lol.They will hold up to 75 lbs of boost!!They block a/f mixtures from getting into crankcase. oil and fuel is no longer blown into intercoolers or intake tracts fouling plugs and no popping oil dipsticks out. I'm going to try these out . If you want more info just go to Speed Circuit website and look these up.
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I do not think the stock ports on the valve cover were really enough.
I am running a PCV delete fitting and check valve with a 3/8" line to the intake and a "Calan (from dsmtuners)" catch can with two -8AN lines from the valve cover to the can and then a single -8AN line to the intake. This is on a built motor (wiseco HD's, manley H beam rods) and its at 750 miles with no oil in the can and no oil in the check valve. I do plan on getting another can for the intake manifold side of things later on.
Notched the pipe at an angle to promote suction (this is connects to the catch can)
Removed the stock baffles and welded some angle aluminum over the ports to block them from direct oil splashing
I am running a PCV delete fitting and check valve with a 3/8" line to the intake and a "Calan (from dsmtuners)" catch can with two -8AN lines from the valve cover to the can and then a single -8AN line to the intake. This is on a built motor (wiseco HD's, manley H beam rods) and its at 750 miles with no oil in the can and no oil in the check valve. I do plan on getting another can for the intake manifold side of things later on.
Notched the pipe at an angle to promote suction (this is connects to the catch can)
Removed the stock baffles and welded some angle aluminum over the ports to block them from direct oil splashing
#208
Answered my own question.
So it looks like under idle conditions the flow goes air filter -> crank case -> intake, effectively flowing fresh air through the crank case and burning crank gasses. Under boost conditions the positive crank case pressure means it flow crank case -> air filter instead, so this is why you need two catch cans.
This begs the question on a single catch can set up why would you put the catch can on the PCV side and not the intake side? All your blow by is going to be at high revs (cam frothing oil) or on boost (blow by) so the time when oil is going to come out the head is on boost, eg when the air filter side is taking the blow by gases. I know most set ups I've seen have the catch can on the air filter side and just leave the stock PCV in place with no filter.
Do you guys agree?
edit: if your PCV is leaking this is even more reason to put the catch can on the air filter side and not the PCV side.
So it looks like under idle conditions the flow goes air filter -> crank case -> intake, effectively flowing fresh air through the crank case and burning crank gasses. Under boost conditions the positive crank case pressure means it flow crank case -> air filter instead, so this is why you need two catch cans.
This begs the question on a single catch can set up why would you put the catch can on the PCV side and not the intake side? All your blow by is going to be at high revs (cam frothing oil) or on boost (blow by) so the time when oil is going to come out the head is on boost, eg when the air filter side is taking the blow by gases. I know most set ups I've seen have the catch can on the air filter side and just leave the stock PCV in place with no filter.
Do you guys agree?
edit: if your PCV is leaking this is even more reason to put the catch can on the air filter side and not the PCV side.
Last edited by foliage; Oct 6, 2014 at 10:14 PM.
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