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I have made the following changes to my shopping list if it makes no sense to change anything on the back side of the engine. This is of-course with the exception of simply putting a can between the OEM PCV in the OEM location and the manifold.
(my intake pipe is one of the old steel ones that ETS made, so I have a steel bung here, I actually have 2 of them incase I have issues welding.)
240Z - Thank you for spending so much time replying with all of those details! I feel kind of dumb, but I think I realize what you were trying to teach me now.
Before I clarify my understanding let me start with a quick description of how the original OEM pcv setup works under easy cruising (manifold vacuum)
Fresh air enters the intake through the filter.
Some of it goes through the turbo, and some gets sucked into the small opening in the valve cover near the transmission side/drivers side.
This air gets sucked through the crankcase, and then travels through the block where it mixes with the nasty crankcase vapors.
It exits the block in the back near the passenger side hole in the back of the valve cover.
It goes through the PCV valve and eventually makes it into the intake manifold.
At this point it gets burned through the cylinders.
So- in order to not have to remove the valve cover and modify it, you are actually REVERSING the flow direction here.
Fresh air enters the air filter
You removed the grommets and make your REAR hole bigger- so this air goes all the way around the back side of the engine and enters the BIG hole in the valve cover through a large 5/8" hose where the PCV valve USED TO GO.
It mixes with crankcase vapors.
It exits the valve cover/block through the LITTLE hole near the driver side/transmission.
It goes through a longer hose and through the PCV valve which you relocated.
It makes its way back into the intake manifold and gets burned in the cylinders.
So essentially it is the same style function as factory, just you are taking advantage of the ability of the rear hole to be easily enlarged where you can make it bigger without the need to remove the valve cover, drill any magnesium or remove baffles.
Instead of traveling "NORTHWEST" inside the crankcase the travel path in your engine is "SOUTHEAST"
Please verify that I understand this correct. If I am correct I want to say this:
I thought about your approach for 2 full days. I do feel dumb for not seeing this originally. I do see the elegance of it.
The thing that I don't like is that it seems like there will be a need for longer hoses. My engine bay is very busy already and I hate to make it even busier. It would be nice however to not need to remove the valve cover and play with the baffles/drilling and such.
The thing I like about my original plan is that I can keep the large port near the intake side of the engine, so I can easily mount my can and keep my hoses short.
I have since thought about it and I DO NOT think I will use the inspection hole in the block for the balance shafts, since it seems this creates a lot of oil making it into the can.
Now that I (hopefully) understand your setup let me ask you this. If I use the driver/side transmission side port of the valve cover for my vent *by enlarging it*, is it silly to do any modifications to the back port where the PCV is? In other words- since the PCV should be CLOSED during boost- why not just keep the back side of the valve cover stock, and only insert the catch can between the oem PCV and the intake manifold.
Thank you once again for your attention to this thread and I appreciate the knowledge you've shared with me!!!
Yes, switch the ports and install a -10an fitting into the rear port if you are going to do a stock configuration setup with catch cans.
My setup is completely different and I only use the rear port with a -10an for PCV both on-boost and off-boost through a single can. The front port is just a vacuum reference for my PCV pressure gauge in the car and my engine is under vacuum (2" - 4") 100% of the time regardless of whether I a cruising on the highway or at 35psi of boost.
Last edited by 240Z TwinTurbo; Apr 27, 2021 at 10:41 AM.
I have made the following changes to my shopping list if it makes no sense to change anything on the back side of the engine. This is of-course with the exception of simply putting a can between the OEM PCV in the OEM location and the manifold.
(my intake pipe is one of the old steel ones that ETS made, so I have a steel bung here, I actually have 2 of them incase I have issues welding.)
$38 for a -10 hose quantity "1" seems ridiculous. I get most of my fittings from www.racetronix.biz and whatever you can't find is usually on amazon.
That's actually 5 ft of hose. Quantity of "1" means 5ft.
The main reason I am doing this is to prevent oil leaks for my seals. I want to do my venting and vacuum on the front drivers side of the engine compartment, so enlarging that port is the way to go for me. I will keep the PCV where it is from the factory. I do not want to route hoses from the passenger side in the back- it's too much hosing.
With the decisions I have made, it would make no sense to convert the rear to AN10 since it is not a vent for crankcase pressure when the engine is boosting hard, right?
Thank you for the measurements, but I think I will leave the PCV valve alone in it's factory spot in the rear. I'm just going to put a can between the PCV and the manifold. I will also put a CAN in between the front breather (which is enlarged) and the intake.
