i am putting on the powerlab 3/8 plenum spacer, and i have noticed while taking the plenum apart that there is a bit of oil resting in places along the lower plenum. is this a normal thing in any way? or do i got a serious problem on my hands?

 

no normal the pcv run in that little channel under the gold metal plate in the middle of the lower half of the upper plenum.

 

try this:https://my350z.com/forum/engine-drivetrain-and-forced-induction-diy/237059-homemade-catch-can.html

 

This is why people install oil catch cans.

 

thanks alot for sharing the knowledge jared and taurran. i wasnt gonna sit there and act like i know everything and just ignore it. wanted to see if you smarter guys could lend me a hand and ease my mind.

 

Then I reply, and the whole thread goes downhill

LOL

 

Good info, thanks for the thread link. Nice work, great DIY.

I notice a lot of pics where people install spacers the plenum has discoloration that looks like a very thin film of oil-color. I've wondered it that was stuff getting past the cone filter, or where it was coming from.

I read the other thread, but am still confused - our PCV runs into the lower intake plenum? Lol, I've replaced PCV's on my SE-R, other Nissans and I realized I never really stopped to consider exactly where that oil mist is going - w/o a catch can - back into the intake for combustion?

Guessing FI makes this more important due to larger pressure rise/drop in the intake?

Thanks in advance, ignorance is not bliss

 

Basically the oil vapors from the crankcase are recirculated into the intake system, so that they are burned with fuel rather than being released to the atmosphere. This is not good for various reasons, including lower fuel octane, contaminating the intercooler system for FI cars, etc. Thus, a catch can, by theory, separates the oil from the air coming from the crankcase. taken from thread.

 

People locally knocked me for installing a catch can on my 350Z. They said since my car is NA that it's a ricer mod. I emptied a decent amount of oil out of it yesterday. I think any 350Z should consider installing 1. I removed my pop charger and had it mounted to the heat shield, so I drained it and moved it next to the power steering res.

 

they are just dumbasses then, any car can benefit from it. If its collecting oil that how is it a ricer mod?

 

IF you don't install a catch can, where does the oil end up???

 

Escobar said it nicely:

 

+1 to that, if it isn't going into the catch can, or pooling in your lower plenum, it's supposedly being fed back into your intake and "combusted".

Call me rice-a-roni, but it's on my NA motor to-do list. I'm installing a spacer in the plenum and after 47k miles and 4 years, I expect to find the lower plenum looks a lot like other people's, covered in oil from either a thin film up to puddles.

I'm pretty ignorant but somehow the idea of a significant amount of oil going back into the intake sounds less than ideal to me.

If it was a chrome can that never saw a drop of oil with anodized hose ends and stainless hose, etc. then I guess you could call it rice or a "dress-up" mod, but if it's collecting oil, then ftw, they're dumbasses.

 

Sounds like the same kind of people who would call putting a shiny KOYO radiator and an oil cooler with filter relocated on my SR20 ('91 SE-R) RICE (as in overkill just for mod's sake) "You don't need an oil cooler on a NA motor, that's for FI..."

They just never had the joy of blowing a head gasket with an overheated engine on the track, so I don't listen much to them. Sure, the engine's NA but near race cams (C2's), the water pump is an under-performer, anything I can do to run it cooler and have 5-6 quarts of oil instead of 3.5 or so, call it RICE all they want...it runs easily ten degrees cooler than w/o, never goes above about 170.

Who cares what they say? It's your car.

 

Thanks. That would really suck going into your IC, but somehow even misting into the intake sounds bad enough for me to do what is essentially a pretty low-cost mod.