Pcv hose reroute to fresh air.

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Brandon-w

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Hey just wondering if anyone has vented their pcv valve to free air, no catch cans or anything? Any factual/personal experiences? My winters get pretty cold so I'd probly end up running it near the exhaust on the way down to prevent freeze off. Just doing a cam swap and decided I don't want that $hit going into my engine its not good for it in any way.
 

VB712

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PCV valve won’t function without vacuum.
 

kurek

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No vacuum means the volatiles in the crankcase just build up, precipitate out into varnishes and acids and you get sticky lifters and galled cams after a decade or so. Doesn't sound very high performance to me but what do I know?

My other car's a Mitsubishi with 307k miles on it, been huffing its PCV straight up for 20 years and runs like new, passes emissions, no check engine light and no loss of performance. Good enough for me unless those Mitsu guys know something the Ram engineers don't.
 

crazykid1994

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Use a catch can. That way you keep a vacuum sucking the goop out and don’t turn your oil to acid. I drain mine about every 2k miles and get about an ounce or two out. If you do oil changes every 3k then you may be fine. Water and fuel vapors mix into the oil and turn to acid if not sucked out first

AE4E7003-05EC-41F5-89F7-412D55BDE1FC.jpeg
 

pacofortacos

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Removing the PCV and leaving that hose and the vent hose open won't hurt anything other than to give you an external oil leak unless you route them to a container - cars ran for decades without them.

It is an emissions device to keep the vapors from the atmosphere.
 

kurek

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It's not about treehugging. Blowby from combustion consists mostly of carbon oxides and water vapor which precipitate out as carbonic acid in your crankcase. The acid doesn't act much on the petrochemical part of your oil (most of it) because that's a nonpolar molecule but any polar additives (zinc, etc) are reactive so the acid accelerates the aging of the oil.

Why do you think cars can get away with 10k mile oil changes now and couldn't in grandpa's day? Sure the oil's better but so is the climate inside your engine. Tighter tolerances in manufacturing mean less blowby, emission controls mean more precise combustion so there are fewer chemical components in the blowby that does occur, efficient crankcase ventilation means the conditions inside the crankcase don't deteriorate over time.

PCV does help keep trees and puppies alive too but it's more about keeping your engine alive. If that's a problem for you then by all means disable it but I'm not going to pretend I understand. :happy160:
 

pacofortacos

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Actually the 10k mile oil changes are also due to piston and piston rings and of course camshaft changes, the PCV system hasn't changed in decades.
I am not sure if blow by is any less now than back in the day either, the hemi in particular seems to have a good bit of blow by - or a poorly designed PCV system as they are known to suck a good bit of oil.
But the pistons are run tighter due to different materials and the piston rings have significantly less tension on them than older engines. Camshafts have roller cams instead of slider tappets.

In the end, the biggest driver of the rec. 10k oil changes are competition. The other manufacturers rec. longer intervals so to keep up on the "cost of ownership" every manufacturer follows suit. European manufacturers really push it, but their oil is different than ours and made for longer change intervals.
http://ultimatesyntheticoil.com/american-engine-oils-harmful-to-european-engines
 

Wild one

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I was thinking about welding this (https://www.moroso.com/pub/media/ca...faab55c849325697b48f66daa1/9/7/97810_part.png) into the exhaust pipe just after the cats; and then connecting my PCV vent hose to it.
What are ya'lls thoughts??
Those don't work all that great if you still have a muffler and or resonators,plus 8ft of exhaust pipe behind it.Those are more for an open header set-up. Even if you're boosted you can still run either 2 catch cans,one off each valve cover,or step up to a Mighty Mouse set-up,if you're not boosted,just buy a normal catch can and plumb it in.
 

Mister Luck

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If your PCV vents to an Air intake Box what’s supposed to come out ? I see these pictures of catch cans with pints of goop is it gravity or a greater vacuum that pulls that liquid out through the PCV ?
Or is it just the hose without the PCV valve attached which would be PCV elimination ?
 

crazykid1994

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If your PCV vents to an Air intake Box what’s supposed to come out ? I see these pictures of catch cans with pints of goop is it gravity or a greater vacuum that pulls that liquid out through the PCV ?
Or is it just the hose without the PCV valve attached which would be PCV elimination ?
Your pcv system runs off vacuum. And on the 5.7 is very easy to follow. There is a pcv valve on the passenger side rear of the intake manifold with a hose that goes into the intake manifold just behind the throttle body. The other side that is connected to the air box goes into the intake manifold again at the front but through a different port into the crank case not into the actual intake manifold. So what is happening is the tube connected behind the throttle body is your vacuum side. The pcv valve restricts the vacuum and prevents and positive pressure coming back into the crank case if there is a backfire. The side into the air box is your fresh air side allowing fresh air into the crank case which is then sucked out by the vacuum side to keep fresh air in the crank case. If you get air coming out your fresh air side into the air box or oil going into the air box then your pcv is bad or restricted. Only under full throttle should you get anything out the fresh air side because the pressure inside the crank case is higher and your vacuum is lower due to the throttle being fully open so pressure in the manifold is near atmospheric. Same as in the air box. Even then it shouldn’t be much.
 

Mister Luck

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Your pcv system runs off vacuum. And on the 5.7 is very easy to follow. There is a pcv valve on the passenger side rear of the intake manifold with a hose that goes into the intake manifold just behind the throttle body. The other side that is connected to the air box goes into the intake manifold again at the front but through a different port into the crank case not into the actual intake manifold. So what is happening is the tube connected behind the throttle body is your vacuum side. The pcv valve restricts the vacuum and prevents and positive pressure coming back into the crank case if there is a backfire. The side into the air box is your fresh air side allowing fresh air into the crank case which is then sucked out by the vacuum side to keep fresh air in the crank case. If you get air coming out your fresh air side into the air box or oil going into the air box then your pcv is bad or restricted. Only under full throttle should you get anything out the fresh air side because the pressure inside the crank case is higher and your vacuum is lower due to the throttle being fully open so pressure in the manifold is near atmospheric. Same as in the air box. Even then it shouldn’t be much.
Is there a diagram for the 5.7 PCV system?
I haven’t found one yet.
 

Wild one

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View attachment 489956
some one help me out and explain which direction is each hose ?
Pink one is the PCV hose you'd plumb a catch can into,the green hose is the crankcase make up air hose.The green hose you don't need to worry about,it stays in place to let filtered air back into the crankcase,when there's vaccum in the pink hose
 

Mister Luck

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Which direction is the pink hose air going ? Back to the PCV or toward the throttle body ?

I’m guessing toward (behind) the throttle plate …
 
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