Dicky Posted March 7, 2020 Share Posted March 7, 2020 (edited) Are there different types of catch can or are they all the same. Watched a YouTube video who referred to it as “vented” ?? Also what’s the difference between 2 port and 3 port cans (please don’t say 1 port :)) Edited March 7, 2020 by Dicky Quote Link to comment Share on other sites More sharing options...
davey_83 Posted March 7, 2020 Share Posted March 7, 2020 Vented is a waste of time and bad for your engine, as you want the engines vacuum to help draw out the crankcase pressure. 2 port needed or 3 possibly for a V6, but the 3rd isn't essential. Quote Link to comment Share on other sites More sharing options...
Dicky Posted March 7, 2020 Author Share Posted March 7, 2020 (edited) Thanks Davey but I thought the pcv outlet was at pressure and so needs to be vented?? Bern looking at You Tube vids which seem to using a vented catch can...I’m confused now! Edited March 7, 2020 by Dicky Quote Link to comment Share on other sites More sharing options...
davey_83 Posted March 8, 2020 Share Posted March 8, 2020 (edited) Be sure you're not looking at a boosted setup. The n/a OE set up is a closed system utilising the engines vacuum to draw out the oil vapour re burning it. The catch can plumbs into this closed system catching the oil vapour, therefore venting to atmosphere doesn't draw out the crankcase pressure nearly as good as a closed vacuum set up. Same principle for our VQ35's using a 2 port unit. Edited March 8, 2020 by davey_83 1 Quote Link to comment Share on other sites More sharing options...
Dicky Posted March 8, 2020 Author Share Posted March 8, 2020 (edited) Thanks so much for your efforts Davey, now I get it and the diagram really helps. I’ve had my car for 15yrs now and it’s probably to late but thought I might fit one just to help the old gal along a bit n her old age. Luv that car!! ps: just had a thought you may be able to advise on. im thinking of running a tube from the PCV and one from the tube which currently connects to the air intake pipe just before the Throttle valve, th t ”teeing” them together into the in port of the catch can, then a tube from the out of the catch can to the plenum vacuum pipe. Do you see any problems with this? Edited March 8, 2020 by Dicky Quote Link to comment Share on other sites More sharing options...
davey_83 Posted March 9, 2020 Share Posted March 9, 2020 I understand the thinking and that would be similar to the ARC catch cans. I would prefer to keep the low and high sides of the system separate as Nissan intended. At wide open throttle the vacuum in the intake becomes atmospheric and shuts the PCV off. Combining the low/high sides could result in excessive oil draw at idle, feeding off both ports. 1 Quote Link to comment Share on other sites More sharing options...
Dicky Posted March 9, 2020 Author Share Posted March 9, 2020 Your a star Davey !! Many thanks for sharing your expertise I will take your advice. Over and out! 1 Quote Link to comment Share on other sites More sharing options...
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