S14DST Posted July 6, 2015 Share Posted July 6, 2015 Hey guys. I recently decided that I need to put breather filters on my pcv system... Is this ok with 350z and it won't need any remap or something else to run properly? I want to put a breather on pcv valve and shut the hole on intake pipe, maybe will add a second breather for LH cylinder head if neccessary... I haven't reasearched this properly, but I've done this on all my s13's (sr,ca) Any opinion or help would be great Quote Link to comment Share on other sites More sharing options...
S14DST Posted July 6, 2015 Author Share Posted July 6, 2015 Oh... And I decided to do this, because after some hard drift laps I get blue smoke from exhaust for a while... I think that pcv system is causing this, because I've read that vq tend to use oil when driven hard :/ (only cats left in exhaust system, got 3" stainless fitted) Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted July 6, 2015 Share Posted July 6, 2015 You shouldn't get blue smoke unless the PCV system is blocked or not functioning correctly, t could be bad ring seal,try a compression test. Personally would leave the PCV system alone, or at least plump a catch can in and run that back to the intake to retain the beneficial effects of it. Quote Link to comment Share on other sites More sharing options...
S14DST Posted July 6, 2015 Author Share Posted July 6, 2015 Pcv valve is working properly and piping seems to be ok... But compression test won't show me the condition of oil rings does it? Because compression is made by the 2 or 3 compression rings... And I had bad piston rings on my daily mazda, the affect was that on cold start until engine is fully in working temperature it had a blue smoke coming from exhaust... I tend to thing that problem isn't in piston rings, because it doesn't smoke daily driving it... I had a blue smoke on highway when I did 50-100mph pull 4-5th gear... It did smoke for a few minutes and then it was back to normal. Maybe I should check all of the pcv sytem pipes from blockage? Or maybe there are something else to check? Will do compression test as soon as I get to my garage... Quote Link to comment Share on other sites More sharing options...
The Chubby Ninja Posted July 6, 2015 Share Posted July 6, 2015 I just drilled my pcv valve out and put a one way valve in line with a little air filter.and the one on the left hand side just put a filter on the end of the pipe. Seems to work fine for me. Bennett put a sticky thread in the forced induction section about the different systems you can use that I found really informative Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted July 6, 2015 Share Posted July 6, 2015 Pcv valve is working properly and piping seems to be ok... But compression test won't show me the condition of oil rings does it? Because compression is made by the 2 or 3 compression rings... And I had bad piston rings on my daily mazda, the affect was that on cold start until engine is fully in working temperature it had a blue smoke coming from exhaust... I tend to thing that problem isn't in piston rings, because it doesn't smoke daily driving it... I had a blue smoke on highway when I did 50-100mph pull 4-5th gear... It did smoke for a few minutes and then it was back to normal. Maybe I should check all of the pcv sytem pipes from blockage? Or maybe there are something else to check? Will do compression test as soon as I get to my garage... Oil control rings don't normally wear without the compression rings being worn also ( unless you have a rev up motor ) so a compression test will show up ring wear,smokingg under load isusuallyy ring/bore wear related, I have not heard of a blocked PCV system on the VQ motor, however they do inhale a lot of oilvaporr at idle/low load, which pools on the bottom of the plenum, which under high load is likely to get drawn into the combustion process and burnt,causingg smoke. If you want to eliminate this, I would fit a catch can to the low load side of the PCV system, ( the left hand cam cover) remove the one way valve and run a hose to the can, you can vent to air or use the intake to provide thevacuume which aids ring seal, don't forget to block off the plenum pipe. Quote Link to comment Share on other sites More sharing options...
S14DST Posted July 6, 2015 Author Share Posted July 6, 2015 (edited) Ok, so maybe I should start with a proper oil catch can breathing into air and see how it works, if that won't help, then it's piston rings for sure :/ But what about valve seals, can't they be faulty/worn? P.S it would be great if someone had a link to a proper/best catch can setup for N/A vq35de with breather setup Oh and mileage is just under 83k miles... But engine was swapped, because genuine engine was first twin turbo in our country which was broken aparts... But previous owner said that this engine is from a lower mileage car and was auto... Edited July 6, 2015 by S14DST Quote Link to comment Share on other sites More sharing options...
GT4 Zed Posted July 6, 2015 Share Posted July 6, 2015 I am venting both pcv to atmosphere with no issues whatsoever. The driver side is vented via a baffled oil catch can and minifliter. I've drilled the pcv one way valve for full venting. The passenger side vent is straight via minifliter. Both intake port are capped to prevent plenum leak and rough running. My engine is a Revup and over 100k hard fast road and track miles including supercharger and still going strong. In effect my intake has no connection to crankcase blowby. While I agree that engine vacuum at idle can help with assisting crankcase ventilation it is not a necessity as the crankcase pressure will always be higher than atmosphere and vent if you remove all restrictions. My engine bay is oil free and the oil catch can does it's job. If you are less extreme then going with a good baffled occ and reconnect to the plenum should limit the oil vapour going into your intake but not 100%. It's key you get a good occ. it's also key you do your compression tests to find out the smoking issue as you will be parking over the cracks. But other than the rings being the problem the valve stem seals are a weak point and using a seal conditioner and engine flush with slightly thicker oil eg 10w40 can reduce the leaks. Which ever route you go make sure you place your minifliter upright to prevent oil drips. 1 Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted July 6, 2015 Share Posted July 6, 2015 Ok, so maybe I should start with a proper oil catch can breathing into air and see how it works, if that won't help, then it's piston rings for sure :/ But what about valve seals, can't they be faulty/worn? P.S it would be great if someone had a link to a proper/best catch can setup for N/A vq35de with breather setup Oh and mileage is just under 83k miles... But engine was swapped, because genuine engine was first twin turbo in our country which was broken aparts... But previous owner said that this engine is from a lower mileage car and was auto... Valve stem seals will usually show up most on cold start, and deceleration I wrote a guide to various PCV and catch tank setups here,http://www.350z-uk.com/topic/89535-oil-catch-can/#entry1349925 PCV systems are designed to provide a vacuum effect to the crankcase at all RPMs and loads to prevent any pressure build up, and actually help with stopping seal weeping and piston ring seal, I disagree that there is always pressure in the crankcase, as I have actually measured this on a couple of different motors both with std PCV systems and modified versions, using catch cans plumbed back into the intake, and at no time did I measure any positive pressure, so they obviously do there job. Quote Link to comment Share on other sites More sharing options...
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