hitmanws6

iTrader: (20)

Last week i decided to try an experiment with my PCV system. I removed the crankcase ventilation hose on the passenger side valve cover, put in a breather filter and capped off the intake port. The results were unexpected, but very good. Immediately following installation of the breather I could feel a smoother idle. The smell of fuel is now gone, so if you are running rich this will lean you out. Acceleration is smoother as well as faster, I attribute this to the adjusted A/F ratio. The oil leak I had had almost stopped, with only a few drops from time to time now. But the big surprise was at the pump. After mixing city/highway miles driving to the same places, it took 13.5 gallons of gas to make my tank full. This time around, after pushing my TA harder than the week before, it took just over 12 gallons to fill the tank. Both fill ups were done at 160 miles. IMO its not a bad mod for just under 20 bucks.

Here is the filter you will need, take the clamp off and push it in. Comes in blue, silver, red and if i remember correctly black. $9.99 at auto zone.

SS RRR

iTrader: (2)

There is something wrong with your PCV system.

shbox

LOL, you can't judge gas mileage only by how many gallons it takes to fill the tank. You have to take the mileage, too and determine MPG.
A breather only is no good for purging harmful gases from your crankcase. A stock, properly fuctioning PCV system should not be giving you any trouble. I know of 600HP+ cars that still use it. Perhaps your situation is unique, but I would recommend anyone try this at their own risk. Long term damage to the engine from lack of purging harmful gases and the resultant residual condensate is a real possibility.
If you had a fuel smell that is now gone, I would expect you need the tune adjusted.

illusions

iTrader: (3)

Are you having oil make it to your intake? Is this the reason for the little filter idea? If so you can get one of the oil separators they use in compressed air lines to filter the oil but still allow the air to be pulled through to evacuate the harmful gases in the engine.

hitmanws6

iTrader: (20)

well the way i see it, 160/13.5=11.85mpg before filter, 160/12=13.33mpg after. my pcv is still hooked up, all i did was remove the hose on the passenger side valve cover. i do understand the risk and im not saying its perfectly ok to do, im just sharing my results

DVS LT1

So it sounds like the factory PCV system is pretty important, is that right?

I've had an engine project in the works for years now and its finally coming due. I recently bought a set of aftermarket fab'd aluminum valve covers with nothing but the center bolt holes. I had planned to punch out and drop in at least one if not two valve cover breathers (one on each side).

My new engine will not be keeping any of EGR or AIR fittings. I hadn't really thought of the PCV thing but just assumed we'd block off the hole on the LT4 intake.

Are you guys saying I may wind up with problems if I do away with the PCV tubes and only go with valve cover breathers?

hitmanws6

iTrader: (20)

pcv valve is 2 months old, nothing is wrong with it

hitmanws6

iTrader: (20)

its a possibility. i look at it the way i look at descreening a MAF. its not recommended to do because of the potential for problems, but people do it anyways. some feel gains, others ruin a MAF.

DVS LT1

Well here's my thing: I don't think I came across many aftermarket valve covers that had fittings for PCV. Most don't even have a hole for oil access like the stock passenger side valve cover does. I just assumed not bothering to punch out a little hole to connect the PCV hose to the intake.

I had the same attitude towards emissions. Since I built a motor from scratch and b/c its not a daily driver or decided not to put back any of the EGR stuff. I've got block off plates for my manifold and once all the bolts are back any holes still exposed will get blocked off too.

"Should" I consider punching a hole in the side of one of my new pretty valve covers to run thatn PCV tube? Really what's the thing for? To vent the crankcase - I thought a valve cover(s) breather would do just fine. Does my intake need that line running into it? Should I have kept the EGR crap?


BTW - unrelated topic but I am missing that angled pan that bolts directly to the bottom of the intake manifold. i remember removing it from my old LT1 intake and for the life of me can't find it. Who knows what this part is called and or any part numbers? I've been searching high and low and don't even know who to describe the thing - its like a oil drip tray with 3 little openings at one end (I guess to let oil? or fluid trip from out ofthe intake and back into the lifter area).

meissenation

iTrader: (2)

I'm confused - I thought the PCV valve was on the intake manifold and the hose goes from the intake manifold into a different port on the intake manifold. It was my understanding that the port on the passenger side valve cover that then goes into the intake was not part of the PCV system and was OK to use a breather on that as long as the PCV on the intake manifold was still in use?

shbox

No, the hose from the TB to the valve cover is very much a part of PCV system. It is the fresh air supply.


Breathers only are ok for a race engine that is torn down all the time, but for a DD it's no good, IMHO. Breathers only do not provide any positive flow out of the crankcase-just a vent. Even the earliest engines that did have breathers on the valve covers had a road draft tube that caused air to be pulled out of the crankcase (the same thing is accomplished by the PCV valve and it's vacuum source). The draft tube was retired to make the system "closed" for emissions purposes (plus it gets rid of the odor).

meissenation

iTrader: (2)

Welp, looks like I need to buy a hose then.

DVS LT1

So I should be modifying my aftermarket valve covers to run the PCV hose as well, huh? If that's the case then I guess it shouldn't be too hard. Just figured I didn't really need it.

I see what the difference is: a vent vs. an active vacum that will pull out the fumes rather than letting the fumes escape on their own.

I actually believe that valve cover breathers are illegal where I live. I remember smelling fumes once I installed mine (with the PCV system still running). Meh...

AChotrod

iTrader: (17)

Anyone know if there is actually a performance loss or gain from using a breather?

Smoke Em

is it worth putting a breather where the pcv tube is on a stock car??

litch2004

iTrader: (1)

to clear things up a little the tube on the valve cover to the intake is not called the PCV; still being a part of the PCV system, the correct name for it is the CCV (Crank Case Vent) hose. The PCV is attached and only attached to the intake manifold. Depending on the year it route from the drivers side about mid way then goes to another hole about 2 inches away, or it starts mid way on the drivers side and attaches to the front of the intake manifold. Like others have said if the problem had is oil residue getting into the intake manifold, then run an oil-to-water separator to help aid in eliminating the oil getting into the intake system.

shbox

In the parts book it is actually called the PCV hose (otherwise sometimes called the PCV/CCV hose). The hose on the other side at the valve is called the PCV valve hose.

litch2004

iTrader: (1)

i was basing my statement off of the diagram that was originally on the factory fan shroud. when i think of the PCV i think of the valve that was originally on the passenger valve cover on the SBC as well as the valve attached to the intake manifold on the LT1. I do understand that this is all part of the same system but for clarification purposes i thought that i has always been best called the CCV and the one on the Manifold called the PCV. This way there is a way to differentiate between the two components of the same system. I just didnt want some one to read this and think that what was removed was the actual PCV when in actuality the only thing removed was a 90*elbow and a hose that went to the throttle body and was replaced with a filter; while the PCV was still retained and attached to the intake manifold.

litch2004

iTrader: (1)

I am not by any means trying to say that you are wrong rob because in actuality you are 100% write.

moderate Z28

I left everything intact and just added a breather where the oil fill cap is. Didnt get any results, didnt expect any either. I did it to see if it would help with the small oil leak I had.
Plus mines a 93, no MAF so I think you can get away with more as far as unmetered air goes.
If anything it looks pretty lol.