cnddodgehead
Well-Known Member
So all of the 6.1 g3 I've seen have no engine venting . What has every one been doing ?
good? bad?
good? bad?
6.1 Venting or no Venting
- Thread starter cnddodgehead
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AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Engines have to be vented. Somewhere somehow,there is a vent.If no vent is engineered in, the engine will make its own.And when it does it wont be appreciated.
To improve on the factory system , Ive been looking at Arringtons oil seperator catch cans , thay look to be very effective . thay are pricey though .
There is a very good technical pdf on there site that goes into good detail on the principals of the ccv system . Ill try do a link.
[ame]http://www.shophemi.com/images/media/p-2591-p-2273-arrington_ccv_bible.pdf[/ame]
There is a very good technical pdf on there site that goes into good detail on the principals of the ccv system . Ill try do a link.
[ame]http://www.shophemi.com/images/media/p-2591-p-2273-arrington_ccv_bible.pdf[/ame]
72BBSwinger
Well-Known Member
Mine will have the factory PCV sucking through a catch with the intake plumbed to a breather tank with a filter.
cnddodgehead
Well-Known Member
ok I am running carb set up with a pvc of back of the carb . I have always believed in venting. . With the factory setup its just threw the pvc as I understand correct?
Rat Patrol
Well-Known Member
Two lines from the intake to a puke tank with breather.
cnddodgehead
Well-Known Member
ok sounds good thanks guys
cnddodgehead
Well-Known Member
Hey Rat patrol ! you were running the modman . I have the pvc off the intake to the back of the carb. there are two spots on the intake to run the breather . is this how you did it? buy the way how is your new intake working?
Buschi340
Well-Known Member
intake to catch tank to rear right of intake? so engine sucks out of the catch can ( which has a breather on top )?
i do currently not much. just a hose where the engine is breathing out ( and IN probably too ) to a catch tank with breather.
Do I need a breather on the oil filler side ( opposite side ) too?
Rat Patrol
Well-Known Member
Lets put aside PCV for a minute – there are three ways you can go about evacuating crankcase vapours (gases).
Remember – the crankcase generates POSITIVE pressure – so gases are always looking to get out of the crankcase. This process CAN can create a re-cycling of air through the crank case..but it’s a relatively weak vacuum effect and the purging effect always takes precedence in a non-vacuum assisted system.
1 – Two lines from the crank case direct to a puke tank with a small air filter. The filter allows for the passage of gas but not moisture out of the bottle – Almost NO air gets drawn back into the crankcase through the bottle as the outward pressure is always greater due to the heating of the crankcase and the displacement of air by oil vapour in the crankcase.
Downsides:
– This system can create a smelly engine bay in excessive oil use situations because of the gases escaping the bottle.
– At low rpm, there is a build up of condensation in the crankcase which can cause premature bearing corrosion
NOTE - Running an oil breather in addition to this system is not advised – as you will purge oil vapour directly into the engine bay – there is NO ‘better route’ for the vapour to take – only to the bottle which is the same pressure bias as outside.
2 – This is a primitive vacuum assisted system. Two lines are run to the headers or exhaust and the exhaust gasses draw the oil vapour out from the crank case.
The issue with this type of system is that crankcase vapours are not constantly pressurised – at low RPM they are less disturbed and there is less oil vapour to displace the air -
Downsides
– Creates more pollution and only works better than a bottle when the exhaust gases are able to create enough pulse to such the gases from the crank case.
– At low rpm, there is a build up of condensation which can cause premature corrosion of bearings.
3 –PCV
This system uses MANOFOLD vacuum to help extract vapours at cruise and low rpm. The vacuum draws ope the valve and sucks gases into the combustion chambers. At high rpm, the crankcase vapours push past the PCV to find their own way to be re-burnt.
Downside – Re-burning of crankcase vapours pollutes the AF mixture to some extent. While this can be ‘tuned for’…in high performance motors which have some oil bypass, or older motors with excessive oil use, it can cause ignition issues such as detonation or fouled plugs.
4 – PCV + Puke tank
Some sustems use the PCV but put a puke tank in the system to condense out moisture before it enters the combustion system.
Others run a separate ‘catch can’, to capture vapours that escape when the motor is shut down – again protecting bearings and providing for the ‘recycling’ of fresh air through the crankcase.
In this case – air CAN enter the crank case because of the suction effect caused by the PCV line. This is the most efficient system.
Remember – the crankcase generates POSITIVE pressure – so gases are always looking to get out of the crankcase. This process CAN can create a re-cycling of air through the crank case..but it’s a relatively weak vacuum effect and the purging effect always takes precedence in a non-vacuum assisted system.
1 – Two lines from the crank case direct to a puke tank with a small air filter. The filter allows for the passage of gas but not moisture out of the bottle – Almost NO air gets drawn back into the crankcase through the bottle as the outward pressure is always greater due to the heating of the crankcase and the displacement of air by oil vapour in the crankcase.
Downsides:
– This system can create a smelly engine bay in excessive oil use situations because of the gases escaping the bottle.
– At low rpm, there is a build up of condensation in the crankcase which can cause premature bearing corrosion
NOTE - Running an oil breather in addition to this system is not advised – as you will purge oil vapour directly into the engine bay – there is NO ‘better route’ for the vapour to take – only to the bottle which is the same pressure bias as outside.
2 – This is a primitive vacuum assisted system. Two lines are run to the headers or exhaust and the exhaust gasses draw the oil vapour out from the crank case.
The issue with this type of system is that crankcase vapours are not constantly pressurised – at low RPM they are less disturbed and there is less oil vapour to displace the air -
Downsides
– Creates more pollution and only works better than a bottle when the exhaust gases are able to create enough pulse to such the gases from the crank case.
– At low rpm, there is a build up of condensation which can cause premature corrosion of bearings.
3 –PCV
This system uses MANOFOLD vacuum to help extract vapours at cruise and low rpm. The vacuum draws ope the valve and sucks gases into the combustion chambers. At high rpm, the crankcase vapours push past the PCV to find their own way to be re-burnt.
Downside – Re-burning of crankcase vapours pollutes the AF mixture to some extent. While this can be ‘tuned for’…in high performance motors which have some oil bypass, or older motors with excessive oil use, it can cause ignition issues such as detonation or fouled plugs.
4 – PCV + Puke tank
Some sustems use the PCV but put a puke tank in the system to condense out moisture before it enters the combustion system.
Others run a separate ‘catch can’, to capture vapours that escape when the motor is shut down – again protecting bearings and providing for the ‘recycling’ of fresh air through the crankcase.
In this case – air CAN enter the crank case because of the suction effect caused by the PCV line. This is the most efficient system.
Rat Patrol
Well-Known Member
Almost forgot....mine is #1 
Buschi340
Well-Known Member
#1.
your 2 lines are routed how? I have a line from rear right in the head where the xv manifold left a port. same kind of port llike in the left front for oil filling. so this passage is going straigth into the crankcase. this line from rear right goes into a standard puke tank with breather. do i need a breather left front? or is there your second line connected? the catch tank has 2 ports. i plugged one but was wandering for what it is good for...
your 2 lines are routed how? I have a line from rear right in the head where the xv manifold left a port. same kind of port llike in the left front for oil filling. so this passage is going straigth into the crankcase. this line from rear right goes into a standard puke tank with breather. do i need a breather left front? or is there your second line connected? the catch tank has 2 ports. i plugged one but was wandering for what it is good for...
Rat Patrol
Well-Known Member
Each head has an oil galleries that provide a direct route to the crankcase.
These are rear right and front left (oil fill) from inside the car.
My intake has port provisions for both these galleries...and I run hoses from both ports to the puke bottle.
If you want to run two separate bottles...ideally you should have a filter on each to assist the oil vapour in passing through the lines into the bottles.....IF neither are vac assisted.
OR
you can run A BREATHER on the front left....and run a PCV on the rear right port with a line to Your bottle....and a second line from the bottle to the carb vac port.
The carb vac will draw air through the PCV, into the bottle, mousture will condense out, while oil fumes pass through the bottle back into the carb port
The breather will assist in circulating fresh air through the crankcase.
This
These are rear right and front left (oil fill) from inside the car.
My intake has port provisions for both these galleries...and I run hoses from both ports to the puke bottle.
If you want to run two separate bottles...ideally you should have a filter on each to assist the oil vapour in passing through the lines into the bottles.....IF neither are vac assisted.
OR
you can run A BREATHER on the front left....and run a PCV on the rear right port with a line to Your bottle....and a second line from the bottle to the carb vac port.
The carb vac will draw air through the PCV, into the bottle, mousture will condense out, while oil fumes pass through the bottle back into the carb port
The breather will assist in circulating fresh air through the crankcase.
This
Buschi340
Well-Known Member
one bottle with two lines to each port. no valve. Sounds best ( and easiest ) to me.
don't want the oil fumes back into the carb.
in the moment the front port is plugged and rear to a puke bottle.
don't want the oil fumes back into the carb.
in the moment the front port is plugged and rear to a puke bottle.
Rat Patrol
Well-Known Member
That Arrington link is a good read..... Theres lots of different options...depends on how much trouble you want to go to...
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