PCV valve hose goes???

[eldubb440]

Agree on all of this except the first part which is a bit confusing...

put a straw in your mouth and suck (pcv).......
ok, yes, the PCV has a one-way check valve yes?

if you plug the other end (breather), you can no longer suck
Not sure what you mean here. If you have a breather, the breather end is open, not closed, correct?

One thing to note here, in keeping with the OP's issue - my car has a carb and he's running EFI. Both can benefit from a PCV valve, but I imagine that each have different requirements for a breather cap vs no breather cap on the opposite side since carb is an open system and EFI is a closed system. Am I correct on that?

if you have a breather opposite of the pcv valve, air enters the engine thru the breather; which is what you want...... no breather, no air; without a breather, the pcv valve is useless

 

[RemCharger]

4 pages of how a positive crankcase ventilation system works.

 

[68 Sport Satellite]

if you have a breather opposite of the pcv valve, air enters the engine thru the breather; which is what you want...... no breather, no air; without a breather, the pcv valve is useless

and in a carb'd engine, the carb is a breather, which explains why my system with no valve cover breather works fine.
It sounds like with EFI, the OP will need a breather cap and a PCV valve.

 

[coloradodave]

4 pages of how a positive crankcase ventilation system works.

Everybody has to start somewhere. Have you ever struggled to understand something and then the right person explains it and your light bulb comes on? I sure have. Let's try this again:
...PCV valve typically goes on one valve cover and a vented breather cap goes on the other. Fresh air is drawn into the crankcase of the engine through the vented breather and ends up in the intake manifold via the PCV valve and engine vacuum. The fresh air and any blowby is then added to the combustion process in the cylinders. A side benefit is that the top of the engine stays much cleaner. Carburetor versus EFI; you're confusing fuel system being open or closed. Not what we're talking about. Open breather on one valve cover and PCV valve on the other: DONE!

 

[RR Fan Dan]

Agree on all of this except the first part which is a bit confusing...

put a straw in your mouth and suck (pcv).......
ok, yes, the PCV has a one-way check valve yes?

if you plug the other end (breather), you can no longer suck
Not sure what you mean here. If you have a breather, the breather end is open, not closed, correct?

One thing to note here, in keeping with the OP's issue - my car has a carb and he's running EFI. Both can benefit from a PCV valve, but I imagine that each have different requirements for a breather cap vs no breather cap on the opposite side since carb is an open system and EFI is a closed system. Am I correct on that?

The PCV doesn’t not stay open the entire time. It is a check valve so to speak.

 

[BLK 68 R/T]

And cars functioned just fine without them for years and years. Including “high performance/hp engines”

 

[eldubb440]

and in a carb'd engine, the carb is a breather, which explains why my system with no valve cover breather works fine.
It sounds like with EFI, the OP will need a breather cap and a PCV valve.

nope...... the carb is not a breather; not in the sense of what we are discussing

it does however create the vacuum that pulls the air into the engine through the breather via the pcv valve

 

[68 Sport Satellite]

Everybody has to start somewhere. Have you ever struggled to understand something and then the right person explains it and your light bulb comes on? I sure have. Let's try this again:
...PCV valve typically goes on one valve cover and a vented breather cap goes on the other. Fresh air is drawn into the crankcase of the engine through the vented breather and ends up in the intake manifold via the PCV valve and engine vacuum. The fresh air and any blowby is then added to the combustion process in the cylinders. A side benefit is that the top of the engine stays much cleaner. Carburetor versus EFI; you're confusing fuel system being open or closed. Not what we're talking about. Open breather on one valve cover and PCV valve on the other: DONE!

much appreciated
PCV valve typically goes on one valve cover and a vented breather cap goes on the other. Fresh air is drawn into the crankcase of the engine through the vented breather and ends up in the intake manifold via the PCV valve and engine vacuum. The fresh air and any blowby is then added to the combustion process in the cylinders.
OK, you had me until I read "via the PCV valve...", but I think I understand. The PCV valve bleeds off excess pressure from the crankcase and also dumps that back into the intake along with the fresh air coming from the breather (is that more accurate?)

 

[eldubb440]

much appreciated
PCV valve typically goes on one valve cover and a vented breather cap goes on the other. Fresh air is drawn into the crankcase of the engine through the vented breather and ends up in the intake manifold via the PCV valve and engine vacuum. The fresh air and any blowby is then added to the combustion process in the cylinders.
OK, you had me until I read "via the PCV valve...", but I think I understand. The PCV valve bleeds off excess pressure from the crankcase and also dumps that back into the intake along with the fresh air coming from the breather (is that more accurate?)

the pcv valve meters the amount of air that gets pulled through the engine and into the intake......it's a constant vacuum leak, the carb is jetted to compensate

 

[RemCharger]

much appreciated
PCV valve typically goes on one valve cover and a vented breather cap goes on the other. Fresh air is drawn into the crankcase of the engine through the vented breather and ends up in the intake manifold via the PCV valve and engine vacuum. The fresh air and any blowby is then added to the combustion process in the cylinders.
OK, you had me until I read "via the PCV valve...", but I think I understand. The PCV valve bleeds off excess pressure from the crankcase and also dumps that back into the intake along with the fresh air coming from the breather (is that more accurate?)

Sorta.... imagine putting a vacuum cleaner to the valve cover. That's basically what the pcv is doing. Vacuuming out the shitty air in the crankcase

 

[eldubb440]

excellent analogy.......my buddy's ex wife could vacuum an entire fleet

 

[eldubb440]

Sorta.... imagine putting a vacuum cleaner to the valve cover. That's basically what the pcv is doing. Vacuuming out the shitty air in the crankcase

and pulling in fresh air through the breather.......the air must come from somewhere

engines with more than acceptable blowby will push more pressure than the pcv can keep up with......and there would be evident "puffing" out of the breather, even the dipstick tube.

 

[eldubb440]

The PCV valve bleeds off excess pressure from the crankcase and also dumps that back into the intake along with the fresh air coming from the breather (is that more accurate?)

yes!

 

[dadsbee]

Can we get this to page 6...

 

[RemCharger]

 

[eldubb440]

Can we get this to page 6...

not by myself, but I'm trying

 

[eldubb440]

moving on to the wiper thread

 

[RR Fan Dan]

Why did the factory put the PCV valves on different sides for different motors?

 

[eldubb440]

AMCs pull air front to back, using the oil fill cap as the breather........and a pcv valve at the rear end of the intake into the lifter valley.

when I ran my cross ram, the intake had no provision for a pcv valve; so I plumbed a pcv valve into each valve cover at the rear of the engine, running one on each carb......it was flawless for years

 

[oldbee]

And cars functioned just fine without them for years and years. Including “high performance/hp engines”

Before that was road draft tubes= oily tops and excessive oil leaks.