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Old 04-08-2015, 06:58 PM   #101
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Originally Posted by Leafy View Post
On a street car I would certainly want a pcv valve on the passengers side and maybe have a catch can on it. The main purpose of the PCV valve is to regulate the amount of vacuum being pulled on the crank case so that you dont pull the full 20inHG ish manifold vacuum that you do in overrun, or even pull the full vacuum of idle. On a racecar with slicks I'd pass on it.
Never heard this. Why is it a problem?
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Old 04-08-2015, 07:00 PM   #102
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Nevermind I reread your post, I think you're saying the VALVE is to regulate vacuum to the crank case, not that the purpose of a PCV system is to regulate vacuum to the engine.
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Old 04-08-2015, 08:34 PM   #103
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Originally Posted by patsmx5 View Post
In case this isn't clear to anyone reading this, PCV is an emissions device, and it's not pulling a vacuum on the block/improving ring sealing. The amount of airflow going through a PCV valve is very very small, like REALLY small. You could install 10 of them and I bet you still couldn't measure more than a few kPa of vacuum.
PCV is not an emissions device, it is not. It is there to prolong the life of the motor. The fact that it's now a check valve plumbed to the intake is because of the environment ONLY.

Slash cut exhaust, crank driven dry sump pump, venturi draft tubes, doesn't matter how it's done but the crank should always be under slight vaccum. The intake is the easiest and cheapest way to do so.

Crankcase ventilation system - Wikipedia, the free encyclopedia

You are destroying your motor slowly not running a proper crank vent setup. Period.
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Old 04-08-2015, 09:23 PM   #104
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PCV is not an emissions device, it is not. It is there to prolong the life of the motor. The fact that it's now a check valve plumbed to the intake is because of the environment ONLY.

Slash cut exhaust, crank driven dry sump pump, venturi draft tubes, doesn't matter how it's done but the crank should always be under slight vaccum. The intake is the easiest and cheapest way to do so.

Crankcase ventilation system - Wikipedia, the free encyclopedia

You are destroying your motor slowly not running a proper crank vent setup. Period.
Did you read the link you posted? It literally says that PCV (Positive Crankcase Ventilation) is an emissions device. The section on PCV explains this, how it came about, etc.

I have a crankcase vent, the stock one, and I'm using it.

PCV is not needed for reliability, it's an emissions device. Read the link you posted.

Agreed that crankcase should be under vacuum for maximum performance, but not required for longevity. Not having a vacuum pump on the engine (the car didn't come with one) or having one isn't going to change the life of the engine. If anything the extra tension on the rings from running a vacuum pump would probably cause more wear on the rings, not less, but I doubt it's significant and a tiny PCV valve with a tiny orifice is doing nothing for crankcase "vacuum". As your link explains, and the name reads, it's for ventilation.
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Old 04-08-2015, 09:40 PM   #105
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You must be ******* retarded. Missed all twenty references to the crankcase vacuum cleaning the oil and everything else of combustion by-products and contaminates?

"The road draft tube, though simple, has shortcomings: it does not function when the vehicle is moving too slowly to create a draft, so postal and other slow-moving delivery vehicles tended to suffer rapid buildup of engine sludge due to poor crankcase ventilation. And non-road vehicles such as boats never generated a draft on the tube, no matter how fast they were going.[2] The draft tube discharged the crankcase gases, composed largely of unburnt hydrocarbons, directly into the air. This created pollution as well as objectionable odors.[2] Moreover, the draft tube could become clogged with snow or ice, in which case crankcase pressure would build and cause oil leaks and gasket failure.[3]"

"During World War II a different type of crankcase ventilation had to be invented to allow tank engines to operate during deep fording operations, where the normal draft tube ventilator would have allowed water to enter the crankcase and destroy the engine.[4] The PCV system and its control valve were invented to meet this need, but no need for it on automobiles was recognized."

"Positive crankcase ventilation was first installed on a widespread basis by law on all new 1961-model cars first sold in California."

So, for you to understand. People have known since the beginning of time about blowby and that letting it settle in the crank is ******* retarded. People let what they had work till the government said no more, as is tradition. They would have just installed breathers like your useless setup if it was better, they would have left the draft tubes out all together. I trust decades of research by automakers before any dumbass assumptions you make, knowing your history.

PCV System - A Breath of Fresh Air

AGCO Automotive Repair Service - Baton Rouge, LA - Detailed Auto Topics - What are the Symptoms of a Bad PCV Valve

I'd list more, but you'd just read what you want to read from it.
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Old 04-08-2015, 09:50 PM   #106
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The oem crank case vent system will not separate oil and return it to the engine without funtioning pcv, the main problem in the system is that the pcv needs an additional oil trap between the valve cover and IM.
Look up post #61 do the same before spending a bunch of time, money and modifications to your valve cover that cannot be reversed.
IT WILL WORK unless your engine is hurt.
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Old 04-08-2015, 10:34 PM   #107
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..rant..
Your wiki link talks about crankcase ventilation, which I have, and use, and it does everything you and your link says. PCV is different, as your link explains, and I don't run it, as your Wiki link explains, it's for emissions.

As your 2nd link in the last post explains, it also helps remove moisture from the oil, which is good for extending oil change intervals.

I'm sure you are right about everything, but I've not used a PCV valve for 8 years and run all the boost and not had problems with it, I've not had blowby, not had oil spewing out of my engine. Think anything you want, this is my experience and so far it has worked just fine. As I mentioned, I even tested using PCV recently, it dumped a bunch of oil in the intake manifold in less than 400 miles! Not what I need running 30+ PSI. If this was a DD and I wanted it to be emissions friendly and have 10k oil change intervals I'd run a PCV valve for sure.
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Old 04-08-2015, 10:36 PM   #108
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Originally Posted by HHammerly View Post
The oem crank case vent system will not separate oil and return it to the engine without funtioning pcv, the main problem in the system is that the pcv needs an additional oil trap between the valve cover and IM.
Look up post #61 do the same before spending a bunch of time, money and modifications to your valve cover that cannot be reversed.
IT WILL WORK unless your engine is hurt.
Agreed. I've never modified my valve cover either, no need for me. As leafy said on slicks, on a track, there could be issues but for me (street car, street tires) no problem.
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Old 04-09-2015, 08:31 AM   #109
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Has anyone hooked their can to the wrong side of the VC? I'm trying to figure if that's why it was filling with oil. I didn't know the ports do different things
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Old 04-09-2015, 09:54 AM   #110
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there's probably a post in here that says adding postive pressure into the VC or catch can isn't smart...
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Old 04-09-2015, 10:35 AM   #111
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Was that for me or someone else? What positive pressure?

Im just trying to find out how the two ports on the valve cover are different.
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Old 04-09-2015, 05:14 PM   #112
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Alex, you should reread this thread, I think you're not comprehending what people are saying. Your pic in post 88 shows a hose connecting the intake manifold to the crankcase breather hose with 2 hoses connected to a catch can. Bad idea, boost goes right from the intake to the engine. There might be a check valve in your pic, but I have a potato that takes clearer pics so it's hard to tell from yours. Either way you're hooked to wrong side of valve cover, yes the sides are different, how dunno, take it apart and see.

Do what I said several times, or what others have said several times, and you'll be fine. If you want to know everything about how it works, read more and take your car apart and test things.
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Old 04-09-2015, 05:30 PM   #113
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Yep, that could put pressurized air/fuel vapor in your catch can and engine.
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Old 04-09-2015, 05:38 PM   #114
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OK, thank you for the explanations. Like I said, been away from the car for a while so I am kind of re-learning this. The whole time I thought both sides did the same thing, just vent pressure out.
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Old 04-09-2015, 06:18 PM   #115
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The bottom of this pic is the "fresh air side" and the top is PCV side. All covers are removed. The PCV side vents engine from back passenger side corner of VC. That's why with stickies and hard left hand corners you can suck pooled oil up through the PCV.


This picture shows the middle cover were the fresh air side breathes. Just between the front and middle hole in the pic. Less chance of sucking up oil.
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Old 04-09-2015, 06:57 PM   #116
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This is how the two vents differ:
The exhaust side vent system has two chambers, it vents blow by gasses in an na engine near full throttle and on a boosted engine whenever there is boost.
Air and oil enters the center chamber and most of the oil is separated and drained back in to the head, all the blow by and some of the oil however makes its way from the top of the center chamber to the bottom of the second chamber where it pools near the back of the chamber (oposite side from the vent port you see outside the valve cover, remember you are on the trottle and there are some g's and engine angle sending the oil away from the vent opening and the transfer tube between chambers enters the second chamber close to the camber floor so oil will hit it and slide toards the back of the engine)
When you get off the gass and on the brakes the pcv valve creates low pressure in the cranckase/valvetrain area and the oil moves toards the front of the seccond chamber where it is sucked up the port where it came from, and it drains back in the center chamber where it is drained back in your engine where it belongs.
This is important, in order for this vent to work you need a SEALED seccond chamber AND a vacuum source (the pcv in this case) without either one the oil that got past the center chamber separator will simply come out the exhaust side vent and there is nothing that you can do about it but to modify the system and do your own r&d to get it right.
You probanly will need a vented catch can on the exhaust vent on a boosted or na engine that spends much of its life at boost or full throttle or has exesive blow by.

The pcv side consist of a single chamber oil separator/vent, in most cases the separator handles the oil well since it only vents past the pcv valve on light or clossed throttle BUT it does let some oil through when you close the throttle at redline or high rpm and boost, under tose conditione some of the oil does get past the seprator and into the im.
This is bad because that oil will lower the octane of the mixture on your next wot run and cause random detonation at high rpm whenever it gets ingested.
To prevent this from hapening I and others have installed a non vented (non vented mishimoto) catch can between the im and valve cover, you do need a pcv valve either on the line between the catch can and im (that is what i preffer) or between the valve cover and carch can (that is what i have).
Good luck and you all can wake up now, i am done.
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Old 04-09-2015, 07:38 PM   #117
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Quote:
Originally Posted by HHammerly View Post
This is how the two vents differ:
The exhaust side vent system has two chambers, it vents blow by gasses in an na engine near full throttle and on a boosted engine whenever there is boost.
Air and oil enters the center chamber and most of the oil is separated and drained back in to the head, all the blow by and some of the oil however makes its way from the top of the center chamber to the bottom of the second chamber where it pools near the back of the chamber (oposite side from the vent port you see outside the valve cover, remember you are on the trottle and there are some g's and engine angle sending the oil away from the vent opening and the transfer tube between chambers enters the second chamber close to the camber floor so oil will hit it and slide toards the back of the engine)
When you get off the gass and on the brakes the pcv valve creates low pressure in the cranckase/valvetrain area and the oil moves toards the front of the seccond chamber where it is sucked up the port where it came from, and it drains back in the center chamber where it is drained back in your engine where it belongs.
This is important, in order for this vent to work you need a SEALED seccond chamber AND a vacuum source (the pcv in this case) without either one the oil that got past the center chamber separator will simply come out the exhaust side vent and there is nothing that you can do about it but to modify the system and do your own r&d to get it right.
You probanly will need a vented catch can on the exhaust vent on a boosted or na engine that spends much of its life at boost or full throttle or has exesive blow by.

The pcv side consist of a single chamber oil separator/vent, in most cases the separator handles the oil well since it only vents past the pcv valve on light or clossed throttle BUT it does let some oil through when you close the throttle at redline or high rpm and boost, under tose conditione some of the oil does get past the seprator and into the im.
This is bad because that oil will lower the octane of the mixture on your next wot run and cause random detonation at high rpm whenever it gets ingested.
To prevent this from hapening I and others have installed a non vented (non vented mishimoto) catch can between the im and valve cover, you do need a pcv valve either on the line between the catch can and im (that is what i preffer) or between the valve cover and carch can (that is what i have).
Good luck and you all can wake up now, i am done.
Thank you, makes some sense now. I ordered a E301 PCV from Rosenthal and will re-do the setup as soon as it comes in.

Would it be beneficial at all to run a PCV in the valve cover and a secondary in the can>IM line or one is enough?
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Old 04-09-2015, 07:46 PM   #118
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I would only use one PCV valve
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Old 04-15-2015, 09:11 AM   #119
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So I set my can up like this


Everything runs good and after about 50 miles and some boost I do not have anything in the can. The can has a dipstick you can use to check level and if I pull this out with the engine running, there is a strong suction through the hole.

Since my can is not filling up, does that pretty much guarantee that my rings are in good condition? I was a bit worried about blowby but wouldn't that start filling up the catch-can? No smoke out of the back either unless the car goes really rich on a pull.
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Old 04-15-2015, 04:15 PM   #120
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The PCV valve is a one-way valve. It only works when you're in vacuum, NOT in boost. So no, blowby under boost isn't going to fill the catch can.

If your catchan works well, it will eventually end up with some water/oil stuff in it that otherwise would have went into the intake manifold.

If it sucks, it won't catch much, and most of the crap goes right through it and into the intake manifold.
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