Block pcv after catch can install

[drifter17a]

All,

 

i am running one pipe from rocker cover to catch can and one from can to intake pipe as per standard setup .

 

there are two breather holes on rocker cover one of which connects to the other on the rocker cover and then connected to intake manifold

 

i have a 3 port baffled moshimoto catch can so will just block one of the in ports.

 

my question is , do i gain anything by running two seperate pipes to catch can from rocker cover rather than following the existing standard setup?

 

2. There is also a pcv valve, can i either block it or run it to the can?

it goes from rocker directly to manifold

 

finally on rb25 neo, there is also a pipe from manifold to the intake and it is rubber sized around 30mm or so, what is that?

[Dose Pipe Sutututu]

Nah no real gain if your car isn't breathing much, also if your motor is stock then the way you've described is more than enough.

I would leave the PCV connected, however once again if your motor breathes a bit then best to block it off to keep your intake manifold clean.

Some useless information, if you have a big HP setup, with a big build - some builders will have slightly larger ring gaps, this in turn creates a little more blow by of which makes it way up to the head and into the cam covers and out the breathers.

[drifter17a]

Mine is modified and have a three port baffle

 

two in and one out

 

connected the rocker together and one from there to in and one from out to turbo induction pipe

 

one is left black with no cap end so sucking air in, is that ok?

 

i don’t know the difference between the port on rocker and pcv 

 

what are their differences?

 

could i connect the pcv to the other in which is currently left to suck air in?

[Joni Boi]

On 3/1/2019 at 6:14 AM, drifter17a said:

finally on rb25 neo, there is also a pipe from manifold to the intake and it is rubber sized around 30mm or so, what is that?

Are you talking about the BOV plumb back pipe that comes from the blow off valve and goes into the intake pipe? or the IACV pipe that comes from the J pipe and goes into the IACV thats sits on the intake manifold? (can't remember what ID their pipes were).

Here's a pic of my catch can setup:

So what you described is correct. My catch can only has 2 outlets, but if you have 3 you can connect both rocker covers to the two ports without joining them like I did, then 1 outlet to the intake. I don't think it matters what ports you use because the turbo creates suction, so the 1 outlet port will be sucking and the other two rocker cover port blowing (). I've left my PVC pipe alone. I'm pretty sure if you block it, your ECU won't like it. (idk)

[drifter17a]

I realised it was the iac valve so that is connected as it should be

 

i worked out what that was so all connected now

 

what i wanted to know was whether i could block pcv and what is the difference between rocker cover and pcv one:)

 

 

[Vodkashotx]

The PCV valve operates only under vacuum; Hence the name positive check valve, This "draws" vapor when the engine is under vacuum pressure (idle, light driving etc) into the intake manifold.

Once the vehicle has positive crank case pressure (boost) the PCV "shuts" and the positive crank case pressure then naturally through the rocker cover breathers.

Yes you can block it off. You will also have to block off the inlet manifold side too. This will effect how the car idles and vacuum pressure.

[Vodkashotx]

I also may be wrong.

God knows, The internet always surprises me.

[89CAL]

PCV = Positive Crankcase Ventilation

[drifter17a]

I have a massive problem

 

with catch can, it is burning oil and blue smoke

i block it back to intake and put a filter on it but the engine bay is as messy as f**k

it is breathing badly so what you guys doing out there?

 

i can’t recirculate as it will burn and blue smoke and probably knock so only option is to air but then filter is socking wet?

[Dose Pipe Sutututu]

Motor is no good

[Ben C34]

1 hour ago, drifter17a said:

I have a massive problem

 

with catch can, it is burning oil and blue smoke

i block it back to intake and put a filter on it but the engine bay is as messy as f**k

it is breathing badly so what you guys doing out there?

 

i can’t recirculate as it will burn and blue smoke and probably knock so only option is to air but then filter is socking wet?

I would agree with dose pipe.

a decent larger can will mask the symptoms, but if you are dealing with a lot of blowby on your engine it likely is a bit tired, or been hurt.

[drifter17a]

Thought of this but compression was 165 psi across all 6 and leak test was 10% at max so what part of motor is bad?

[Ben C34]

Just now, drifter17a said:

Thought of this but compression was 165 psi across all 6 and leak test was 10% at max so what part of motor is bad?

The fact there is heaps of blowby shows the rings aren't really doing a good job.

comp test while cranking doesn't really show what's happening when revving and making power, which in your case is heaps of blowby.

fit the biggest catch can you can

[drifter17a]

This is what i have but mine is three port

most catch cans are small but will try and get a bigger one

 

 

https://h-tune.co.uk/mishimoto-compact-baffled-oil-catch-can-2-port/?currency=GBP&gclid=EAIaIQobChMI9cr9pqqZ4QIVBrDtCh1NVwQTEAQYBCABEgLHQ_D_BwE

[Ben C34]

You need something like hhttp://www.lewisengines.com.au/nissan-skyline-r33-catch-can/

[GTSBoy]

Compression rings and oil control rings are 2 separate parts.  Possible to have rooted oil control rings while still having reasonable compression.

And.....165 psi is f**king high, not normal, indicating either, wet cylinder walls or a compression gauge that can't be trusted.

[admS15]

Is pcv in or out?

 

Did this only recently start happening after you changed something?

 

 

[drifter17a]

In

[drifter17a]

update, pcv removed and redone the fittings and situation is considerably better with minimal oil

 

i bought a second 2 liter catch can

https://www.ebay.co.uk/itm/Universal-2-Litre-Oil-Catch-Can-Tank-Reservoir-with-Billet-Aluminium-Cap-Black/222719067847?hash=item33db1746c7:g:-lEAAOSwyXNaEqW1

 

i have a moshimoto 3 port so a waste to through it away so how i am planning to do it is 2 input from rocker to ins on the moshimoto then output from moshimoto to the newely bought 2 liter can and then output from that can to air .

 

so messiness should be minimised.

 

has anyone here got two catch cans or see an issue with such setup ?

Edited March 26, 2019 by drifter17a

[Ben C34]

That would mean the pcv want working properly, or you have plumber something up weird. No pics means you probably have done something weird