explain how a breather system could be bad
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TECH Resident
Joined: Apr 2005
Posts: 814
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From: NJ
explain how a breather system could be bad can someone explain how or why deleting the pcv would be bad. wouldnt a open breather release as much crankcase pressure as the motor would build up being its practically open. i have a catch can and its catching a ton of oil and i wanna do the pcv delete but i keep reading people saying "oh its bad" well id just like someone opinions on why. and if u feel its good post that to Thanks
-Ryan
-Ryan
Breather will give you atmospheric crankcase pressure
at best. With any blowby, it will be over pressure and
seals will weep.
Breather draws in no fresh air, so your crankcase is
going to be full of blowby gasses to condense into the
oil.
PCV combination of suction and air purge keeps the oil
cleaner and in the motor. At least until rings wear so
badly that ther PCV can't keep up anymore, then you
may as well go breather.
at best. With any blowby, it will be over pressure and
seals will weep.
Breather draws in no fresh air, so your crankcase is
going to be full of blowby gasses to condense into the
oil.
PCV combination of suction and air purge keeps the oil
cleaner and in the motor. At least until rings wear so
badly that ther PCV can't keep up anymore, then you
may as well go breather.
Originally Posted by jimmyblue
Breather will give you atmospheric crankcase pressure
at best. With any blowby, it will be over pressure and
seals will weep.
Breather draws in no fresh air, so your crankcase is
going to be full of blowby gasses to condense into the
oil.
PCV combination of suction and air purge keeps the oil
cleaner and in the motor. At least until rings wear so
badly that ther PCV can't keep up anymore, then you
may as well go breather.
at best. With any blowby, it will be over pressure and
seals will weep.
Breather draws in no fresh air, so your crankcase is
going to be full of blowby gasses to condense into the
oil.
PCV combination of suction and air purge keeps the oil
cleaner and in the motor. At least until rings wear so
badly that ther PCV can't keep up anymore, then you
may as well go breather.
Here is a response I got through a pm:
Well the catch can is for a closed crankcase system.
The blowby or combution gasses that make it past the pistons/ rings goes into the crankcase. This sends alot of combustion byproducts, acid parrifin etc into the oil . Not to mention a certain amount of pressure depending upon the condition or build in clearances of the motor. A worn engine or one built
loose will produce more blow by. This can even be felt & measured as a pressure.
The PCV & crankcase vent hose route the the manilold vacuum thru a metered oriffice(PCV).
The vent hose is usually to the trottle body or to the intake duct for part to WOT usuage. These do suck oil into the crankcase, but they help alleviate the crankcase of combustion blow by & it's gasses.
If you put a breater in the system you create a vacuum leak in the PCV/crankcase system.
The catch can is designed to go between the vacuum & the PCV & it catches the oil that mists in the PCV system & keeps it from going into the motor.
I use this one http://www.accmachtech.com/pcvcatchcans.htm
It woks very well for me, very little oil in my intake quite a few miles & huge cam.
You can run an open sytem alla race car, but IMO you need to change the oil more often due to contamination from blowby.
Once they added PCV's in the 60's the motors started lasting longer due to it.
Well the catch can is for a closed crankcase system.
The blowby or combution gasses that make it past the pistons/ rings goes into the crankcase. This sends alot of combustion byproducts, acid parrifin etc into the oil . Not to mention a certain amount of pressure depending upon the condition or build in clearances of the motor. A worn engine or one built
loose will produce more blow by. This can even be felt & measured as a pressure.
The PCV & crankcase vent hose route the the manilold vacuum thru a metered oriffice(PCV).
The vent hose is usually to the trottle body or to the intake duct for part to WOT usuage. These do suck oil into the crankcase, but they help alleviate the crankcase of combustion blow by & it's gasses.
If you put a breater in the system you create a vacuum leak in the PCV/crankcase system.
The catch can is designed to go between the vacuum & the PCV & it catches the oil that mists in the PCV system & keeps it from going into the motor.
I use this one http://www.accmachtech.com/pcvcatchcans.htm
It woks very well for me, very little oil in my intake quite a few miles & huge cam.
You can run an open sytem alla race car, but IMO you need to change the oil more often due to contamination from blowby.
Once they added PCV's in the 60's the motors started lasting longer due to it.
^^^ Awesome information! ^^^
BTW - That AMW catch can is overpriced. Though it is one of the best available, there are much cheaper alternatives. It was a *bit* overpriced when they sold it for $80, then the price up and doubled overnight, literally.
BTW - That AMW catch can is overpriced. Though it is one of the best available, there are much cheaper alternatives. It was a *bit* overpriced when they sold it for $80, then the price up and doubled overnight, literally.
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Originally Posted by scrmnws6
You can go to a Home Depot and get one for an air compressor for under $20.
where would that be located(what department)? Id be all about making a kit from homedepot if I knew what to look for.
Originally Posted by jimmyblue
Breather will give you atmospheric crankcase pressure
at best. With any blowby, it will be over pressure and
seals will weep.
Breather draws in no fresh air, so your crankcase is
going to be full of blowby gasses to condense into the
oil.
PCV combination of suction and air purge keeps the oil
cleaner and in the motor. At least until rings wear so
badly that ther PCV can't keep up anymore, then you
may as well go breather.
at best. With any blowby, it will be over pressure and
seals will weep.
Breather draws in no fresh air, so your crankcase is
going to be full of blowby gasses to condense into the
oil.
PCV combination of suction and air purge keeps the oil
cleaner and in the motor. At least until rings wear so
badly that ther PCV can't keep up anymore, then you
may as well go breather.
