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Just bought a z06 and the catch can line is going from the dry sump to the catch can and from the port under the intake to the catch can..from all the other diagrams and pictures I've seen the way the guy ran it is wrong..will it hurt anything to run it like this?
Normally hose should come from valley cover vent to catch can and from catch can to intake nipple post tb.this is a kinda lower horsepower setup(more than stock thou).for higher horsepower bigger hose comes from valve cover fill cap to catch can and then to nipple post tb.plug off valley nipple.On my first example,the catch can is usually mounted on the passenger head.second example,the catch can is mounted by the dry sump tank.are you getting oil in catch can as it is?
Last edited by angeldog; Jul 10, 2020 at 10:41 PM.
Mostly condensation..real milky but the guy who had it only drove it 1500 miles in 4 years..the container was full
On a normal street driven C6 your catch can should have a couple tablespoons of oil at most after 1500 miles, and that would be excessive. If more then that you have issues. I've also never seen milky. YMMV
Need to know more about the can, and if the top filter section has a one way valve that is preventing vacuum from coming back into the can from the filter.
If top filter does have a check valve that only allows extra can air pressure to come out, system will work as is, but will not have a vacuum at WOT to draw the vapors into the can then.
Hence during WOT, intake manifold does not have a vacuum, and the oil tank on the clean side of the PVC system is normally piped to the air filter hose section just in front of the TB that does have a vacuum at WOT instead.
As for the milk in the can, with what little the car was driven, was normal humidity in the oil that collected, and just vapored out to the can once you did start driving the car enough to bring the motor oil up to temp to start vaping the water out of the oil. Hence should have changed the oil when you got the car, since will bank that is was not being changed out yearling.
There wasn't a one way valve..I'm going to remove the can and run the lines the way it came from the factory until I get my mighty mouse can.. Is there any chance putting it back to factory will cause it to run lean or rich? I'm sure it was tuned with the catch can on.
There wasn't a one way valve..I'm going to remove the can and run the lines the way it came from the factory until I get my mighty mouse can.. Is there any chance putting it back to factory will cause it to run lean or rich? I'm sure it was tuned with the catch can on.
Without one way check vavle on the cans filter, car was tuned for a lot of un-metered air that was being sucked in from the filter back to the intake manifold as a constant. So without this air, motor is going to run on the richer side at WOT when the motor is running in open loop. So with luck, the filter was in a oil soaked state to begin with during the tune, while may have acted at some sort of check valve to begin with.
Also to point out, without a filter check valve so the can could go into a vaccum state from the intake vacuum at less than WOT, surprised that the catch can was working at all. So since can was on the fuller side, would bank that the filter got oil soaked quickly to reduce the amount of air flow through it, which allowed the can to build up a vacuum to draw vapor out of the motors oil cavity areas to begin with.
Hence the only time you should need a filter on a catch can (and needs back check valve), is when running boost. This is because of the piston blow by under hard boost that will over whelm the oil void area in the motor/PCV system, and allows that boost pressure to just blow out of the can via the filter, isntead of blowing a hose off isntead. Any other times, can should not be able to such air back through the filter, which allows the can to be in a vacuum state to vacuum draw vapors out of the motor via the dirty and clean sides of the PCV system, to keep the motor oil cleaner.
Again, at less than WOT, can is drying this vaccum from the intake manifold port. At WOT, the vaccum draw is from the air filter piping just in front of the TB instead.
So since this is a Dry sump motor, would run with the elite catch systems.
Hence single catch can between the intake port and valley port to catch the dirty side with a sealed can. This puts the catch can in an areas that make is easy to unscrew the bottom section to dump it during oil changes.
On the oil pump tank, plug the front vent port, then change out the tank cap to an oil separator cap, than vents to the port in front of the TB at WOT only.
Hence oil vapor from the tank/valve covers with baffles are is on the cleaner side, and instead of trapping the cleaner oil vapors to loose that oil, it just catch and dropped back down to the tank isntead.
So again, at less than WOT, intake manifold port is creating all the vacuum to trap the oil from the dirty side valley cover with baffle. At WOT, air filter piping in front of the TB is creating a vacuum, and that is where the tank vent is getting it vacuum during WOT instead. When not at WOT, tank is getting it vacuum from the valve cover lines, that the intake manifold port that has the valley cover/rest of the motor under vacuum to keep the motor oil cleaner instead.
Where does the other tube go? You need to use the valley pan as one as there is an air restricter in there of .100 (see photo) (hidden inside of the tube) the other goes to the intake. I agree with guy above about all the unmetered air if you had line going from manifold to dry sump tank with no restriction. The little .100 hole only allows 3 cfm at 18 inches of vacuum to go through there which is not much but is enough to PCV. By going to the non restricted 3/8 line (no matter where it is going/coming from) you are opening it up 10+ times which is not good - basically big vacuum leak. Now if you have a blower it will be different this is for the NA guys.
Last edited by double06; Jul 11, 2020 at 01:28 PM.
Reason: adding stuff
Well since the intake is capped and the air bridge is capped and the valley venting to the can with a line from the sump tank you basically had no PCV and you were pressure venting out the air filter there under hard load. The PCV only comes with suction so with the manifold and the air bridge capped all you got is vents. The valley is not too much of a vent as it has that restricter in there most of the vent is coming from the sump tank with the valley covers venting to the tank and then out the catch can air filter. I would convert the hole system back to stock and add the catch can like Dano in post 11. The vent one you have is not a good choice for that mode as it defeats the purpose of cleaning out the bad air in the engine as it will take path of least resistance and suck fresh air in through the air filter thus no providing evacuation of the crankcase air.
That is not a catch, but is a vent can is is plumbed correctly. The way it is plumbed does not allow any oil into the intake manifold- this is a good thing. Any excess crankcase pressure is now relieved by exiting the filter on top. Will it catch oil, yes and yes will need to empty it from time to time based on how the car is driven. Although I prefer to vent each rocker cover with a -10 hose on each and a -12, preferably a -16, hose on the dry sump tank, this way it is should be fine for a street car.
That is not a catch, but is a vent can is is plumbed correctly. The way it is plumbed does not allow any oil into the intake manifold- this is a good thing. Any excess crankcase pressure is now relieved by exiting the filter on top. Will it catch oil, yes and yes will need to empty it from time to time based on how the car is driven. Although I prefer to vent each rocker cover with a -10 hose on each and a -12, preferably a -16, hose on the dry sump tank, this way it is should be fine for a street car.
Problem is a vent can does not draw out what is boiling out of the motor oil (keeps the motor oil gallery at a vacuum to vapor dray out), so motor oil become dirty/ stays contaminated more than normal instead.
Problem is a vent can does not draw out what is boiling out of the motor oil (keeps the motor oil gallery at a vacuum to vapor dray out), so motor oil become dirty/ stays contaminated more than normal instead.
Whatever is boiling out is in the hoses to the vent can where in condenses back to liquid when it cools. All a catch does is put oil into the intake manifold where it is sucked in and detonation occurs. This leads to ring flutter and broken pistons.There comes a time when that little hose to and from a catch can is overwhelmed and the little hose from the tank top to pre throttle body starts pushing oil into the air intake tract, coating the maf and skewing its' readings. With that much crankcase pressure, most likely the rear main seal will leak. I've seen this many times. All the track day and race cars we build utilize a breather can, usually a Peterson 08-0400.
Z06 catch can installed wrong
