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Something i learned....

G

GTP4

New member
Wrong title, but still need ur help.
Do i need a valve cover breather installed, since the pcv valve got covered by the ls1 tb,so the motor doesn't build pressure?
ZZ Performance
Its building pressure and making a loud whisle, like a old coffe maker.[:D]
Specially when i turn the car off.[:@]
 
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O, can somebody tell me what this means?
*PCM programming required on cars with drive by wire throttle bodies

I have an ls1 tb, dont know if it applies to me.
 
I wouldnt put a breather on it because then you would be allowing unmetered air into the motor. Some people put on custom pcv systems. Some just put a vent tube from a valve cover or the oil filler cap and route it to the intake. So it vents out the gases and pressure build up back into the intake.
 
GRANDPRIXFOOL01 said:
I wouldnt put a breather on it because then you would be allowing unmetered air into the motor. Some people put on custom pcv systems. Some just put a vent tube from a valve cover or the oil filler cap and route it to the intake. So it vents out the gases and pressure build up back into the intake.
Click to expand...
ok the only problem that I can see with that is sucking oil from the cover into the tube.
your not going to hurt your motor by putting a valve cover breather on it, could help.
although my preference would be to use one with a shield or prefilter, to keep out any water or other stuff.
 


its my understanding that it (pvc) has been pluged. if so then he needs crank case ventilation some how (breather).
although, I have to say that the normal pvc would be ideal.
 
i wouldnt run anything without a pcv valve , i neglected to put one on my 59 and drove it for maybe 500 miles and pulled the valve cover to adjust the rockers , all kinds of milky yuck and condensation on the insides of my valve covers. added a pcv valve and two years with the covers off about three times a summer and never seen anything inside my valve covers again.
 
justwhisen said:
its my understanding that it (pvc) has been pluged. if so then he needs crank case ventilation some how (breather).
although, I have to say that the normal pvc would be ideal.
Click to expand...

You are correct.

A breather = BIG Vacuum leak, and is the cheap easy way around correctly hooking up your PCV system so it works correctly.

To get rid of your squealing, you need a vent, and the breather can offer this yes. Many run them...also, many do not need them. Many buy them cause they look pretty more than anything.

But at the same time, they hurt you in the long run regardless on our motors.

Next time it starts squealing, pop the hood, and uncap your oil fill cap, and it will stop, and there you have it...you have purged the PVC system. Same thing the breather will do...or if the PCV system was operating correctly.

I used to run a breather, then wised up, and hooked up my stock PCV system. I have to say, doing this on a GenIII M90 and a LS1 TB set up was not easy to figure out, a GenV and a LS1 TB set up, like i have now was cake. They give you a port on the back of a GenV that you just plumb into your intake tube...easy as I just typed that. LOL

~F~
 
make it work correctly and you wont have a problem.

otherwise youre going to have to deal with the side effects of not having a correctly running car.
 


Well you have to put it at a spot in the intake that does not see vac. Luckily my n* adaptor plate has a port on it witch was perfect. I forget where it was in relationship to the throttle blade. I believe it has to be on the motor side of the throttle blade. And of course after the maf so that it is metered air. It is merely a vent to expell any gases or pressure. One draw back that I have heard about is that it may possibly allow minimal oil to go past the rotors in the blower but I have checked inside after a month and a have or so and all seems well so I stucking with it for now at least. I used a step bit and drilled a hole in the oil filler neck extension and threaded in a nipple and ran a line up to the adaptor plate.
 
On a Gen III setup, the PCV flow looks like this:
PCVFlow.jpg


Air is pulled into the TB, through the s/c case down through the front head, then through the crankcase and back up through the rear head to the top of the s/c case through the PCV valve.

You can put a breather on the front valve cover to let air in, but then you introduce air outside the metered flow and throw off fueling. One way to avoid unmetered air is to cap the PCV valve so that the air entering through the breather does not get introduced into the a/f mix. The breather then becomes the entry and exit point for crankcase ventilation, which is not the ideal solution, but works. I have that setup on my turbo install right now.

If you can't tap a hole through the LS1 TB, a better fix is to run a line from before your MAF to the front valve cover, then run a line from the rear valve cover to a catch can, and then back to before the MAF again. The entry line should point into the airstream, and the return line should point opposite to the airstream to create flow. The stock PCV valve must then be blocked off.
 
Yeah, i've been told turbo set ups run with breathers.
I'v talked to several memebers, and they have run breathers for couple of years with no problem.
We did some tuning yesterday and everything checked out good.
So i'll run with it, c what happens.
Even zz performance told me it was ok to run one.
 
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