KA Pressure in head, heavy smoke from exhaust - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

mewantkouki · 02-18-2018, 02:59 PM

Pretty sure the large fitting on the valve cover is designed to suck fresh air into the crank case and the pcv valve & tree that runs to the intake manifold (stock) is designed to pull negative pressure and oily crap through the breather / separator box and be burnt out through the engine. So under boost I would run that line to a catch can under vacuum. (block) and have the valve cover breather connected to a separate catch can (atmospherically vented) with no vacuum source on it.

Hoffman5982 · 02-27-2018, 06:59 PM

Quote:

Originally Posted by mewantkouki

Pretty sure the large fitting on the valve cover is designed to suck fresh air into the crank case and the pcv valve & tree that runs to the intake manifold (stock) is designed to pull negative pressure and oily crap through the breather / separator box and be burnt out through the engine. So under boost I would run that line to a catch can under vacuum. (block) and have the valve cover breather connected to a separate catch can (atmospherically vented) with no vacuum source on it.

Well I hope it's not supposed to be sucking because mine is definitely blowing air. It's connected to the air intake on an na setup so I would think that pulls a vacuum on it.

It seems I still have smoke. Definitely not as much as it was as I can never see it(I do smell oil from time to time though), but my friend was behind me and said it was definitely smoking. The car runs great though. Not sure why a freshly rebuilt motor would have this much blowby, but I'm just going to rock it I guess. Maybe the rings haven't fully seated(I've put maybe 600 miles on it). I gapped the rings to Ross's specs, I believe .019 on the top rings and .021 on the second ring. Made sure everything was oriented correctly and so on. I guess we'll find out if it blows up again at this next drift event lol

02-18-2018, 02:59 PM	#1
mewantkouki Zilvia FREAK! Join Date: Nov 2007 Location: Orlando, Fl Age: 38 Posts: 1,250 Trader Rating: (36) Feedback Score: 36 reviews	Pretty sure the large fitting on the valve cover is designed to suck fresh air into the crank case and the pcv valve & tree that runs to the intake manifold (stock) is designed to pull negative pressure and oily crap through the breather / separator box and be burnt out through the engine. So under boost I would run that line to a catch can under vacuum. (block) and have the valve cover breather connected to a separate catch can (atmospherically vented) with no vacuum source on it.