Help me solve my oil consumption!
Run a sealed catch can from the valley cover to the intake manifold and run the valve covers to a breather can or install breathers on the covers. I believe the valley cover should have a built in PCV if not a PCV in the line from the valley cover to the catch can and then to the intake manifold. If breathers are out of the question Mighty Mouse or Saikou Michi dual catch cans are good choices.
If you do this on a Mass Air tuned car like these all are stock you will have unmetered air and a tuning issue, as the air the PCV system draws in to filter the crankcase no longer is measured by the sensor.
What David said...
"if you are connecting the can to the valley plate either you need to have a valley plate with the built in pcv or you need to have a pcv in-line. check your part numbers"..
Like the catch can he makes w/ a pcv in it.
"if you are connecting the can to the valley plate either you need to have a valley plate with the built in pcv or you need to have a pcv in-line. check your part numbers"..
Like the catch can he makes w/ a pcv in it.
TECH Senior Member
Joined: Jan 2004
Posts: 5,798
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From: St.Charles MO
Other than a catch can what can you do with keeping the whole PCV system intact? Does someone make a different valley cover and valve cover for better pcv flow or something?
About a week ago a Z06 pull into a gas station and I noticed he had a decent cam in the engine. Asked if I could check out his set up and he was running a sealed catch can from the valley cover to the intake and breathers on each valve cover. Are you saying a MAF tuned vehicle cannot be set up like this?
TECH Senior Member
Joined: Jan 2004
Posts: 5,798
Likes: 16
From: St.Charles MO
About a week ago a Z06 pull into a gas station and I noticed he had a decent cam in the engine. Asked if I could check out his set up and he was running a sealed catch can from the valley cover to the intake and breathers on each valve cover. Are you saying a MAF tuned vehicle cannot be set up like this?
The intake creates vacuum on the crankcase through the dirty line of the pcv system. That crankcase then pulls the air from above through the clean line of the PCV system that is hooked to the throttle body. This is a closed loop, all of the air that goes into the engine is read through the MAF.
So again with the cycle, the intake creates vacuum, creating vacuum in the crankcase and if there is an open breather on the engine the crankcase will pull the air through the breather, and the intake will suck up that unmetered air from the crankcase. This is why you want a one-way check valve on the breather if you want to run a breather, that way it only lets air out (revealing any excess pressure, like blow by) but not letting any unmetered air go back into the engine. Then you can put another check valve on the clean line to let air be pulled in but not have oil come back out.
What about just running 10 AN lines of your valve covers to a breather can then capping off the throttle body, valley cover and intake manifold ports? This way you will not have the problems of oil getting into the intake to alter the air/fuel mixture and reducing your octane points, not to mention coating your valves, fuel injectors and combustion chambers with cooked on oil and eventually making its way down to clog up your O2's and your catalyst.
I was running a sealed catch can from the valley cover to the intake with the valve covers going to the throttle body port. But the problem I ran into was oil pooling up in the back of the intake and being sucked into the back runners then onto the backside of the intake valves so every time the intake valves opened the oil dumped down into the back cylinders soaking the back plugs with oil and eventually causing them to foul. Still not 100% sure which direction I will go but am certainly leaning towards venting to atmosphere. If PCV is that critical and I'm still a skeptic on the issue I suppose I could run a vac pump to pull from the valley cover to another breather can and still keep the oil vapors out of my combustion chambers!
I was running a sealed catch can from the valley cover to the intake with the valve covers going to the throttle body port. But the problem I ran into was oil pooling up in the back of the intake and being sucked into the back runners then onto the backside of the intake valves so every time the intake valves opened the oil dumped down into the back cylinders soaking the back plugs with oil and eventually causing them to foul. Still not 100% sure which direction I will go but am certainly leaning towards venting to atmosphere. If PCV is that critical and I'm still a skeptic on the issue I suppose I could run a vac pump to pull from the valley cover to another breather can and still keep the oil vapors out of my combustion chambers!
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Verdad Gallardo TECH Senior Member
Joined: Jan 2004
Posts: 5,798
Likes: 16
From: St.Charles MO
With that setup the crankcase has no vacuum then to pull the old air out and bring new fresh air in, that is a problem with an engine that isn't strictly a race engine with often oil changes.
I was running a sealed catch can from the valley cover to the intake with the valve covers going to the throttle body port. But the problem I ran into was oil pooling up in the back of the intake and being sucked into the back runners then onto the backside of the intake valves so every time the intake valves opened the oil dumped down into the back cylinders soaking the back plugs with oil and eventually causing them to foul. Still not 100% sure which direction I will go but am certainly leaning towards venting to atmosphere. If PCV is that critical and I'm still a skeptic on the issue I suppose I could run a vac pump to pull from the valley cover to another breather can and still keep the oil vapors out of my combustion chambers!
Why run a catch can at all with that setup, and not just put breathers on the valve covers?
With that setup the crankcase has no vacuum then to pull the old air out and bring new fresh air in, that is a problem with an engine that isn't strictly a race engine with often oil changes.
This is because either the catch can you had was not good enough (cheap ebay ones can catch some oil but not all of it, so don't think that because the catch can has some oil it in that its 100% doing its job, some may be getting through). Or because oil vapor is coming back up through the clean line that attaches to the throttle body. Check the throttle top hole that the line connects to an see if its coated in oil. If it is you can either run an addition catch can for that line or you can do what I said earlier and put a one-way out (only letting air go into the crankcase and not back up that line) check valve on that line and use a one way out check valve breather on the oil cap (only letting air out and not back in, this will release any excess pressure.)
With that setup the crankcase has no vacuum then to pull the old air out and bring new fresh air in, that is a problem with an engine that isn't strictly a race engine with often oil changes.
This is because either the catch can you had was not good enough (cheap ebay ones can catch some oil but not all of it, so don't think that because the catch can has some oil it in that its 100% doing its job, some may be getting through). Or because oil vapor is coming back up through the clean line that attaches to the throttle body. Check the throttle top hole that the line connects to an see if its coated in oil. If it is you can either run an addition catch can for that line or you can do what I said earlier and put a one-way out (only letting air go into the crankcase and not back up that line) check valve on that line and use a one way out check valve breather on the oil cap (only letting air out and not back in, this will release any excess pressure.)
Sir go to you tube and look up the fastest 5th Gen. Camaro with twin turbos by NRE. Also do a search titled "crankcase breathers" from Snakebite and then get back with me on the old PCV debate. Good enough for forced induction then good enough for us old N/A motors too...
TECH Senior Member
Joined: Jan 2004
Posts: 5,798
Likes: 16
From: St.Charles MO
Was running a Norris Motorsports sealed catch can connected from the valley cover to the intake manifold port. The two valve covers connected to the throttle body port by way of a T. Your saying to keep the sealed catch can as installed and run either an additional catch can or a one way valve connected from the line on the valve covers to the throttle body and then have two ways for oil vapors to make their way into the intake manifold and to do what? Let me hear it!
Keep the catch can the way it is. Remove the T-fitting on the clean line, its not needed. Run the clean line like it is in the stock location, from the passenger side valve cover to the throttle body, only this time with a one-way check valve in it. The check valve will let air come from the throttle body into the valve cover but not let air/oil vapor come from the valve cover to throttle body - that is likely where you are getting oil from. Then you replace your oil cap with a specific breather, one that has a check valve built in to let air out of the valve cover but not back in. This way any excess pressure that would normally shoot up the clean line into your throttle body is now being stopped by the check valve in the clean line and being released through the breather instead. But the breather will not let any air back into the system that would cause a vacuum leak condition on a MAF car. If the car doesn't run a MAF then that is a different story and things can be setup differently.
Sir go to you tube and look up the fastest 5th Gen. Camaro with twin turbos by NRE. Also do a search titled "crankcase breathers" from Snakebite and then get back with me on the old PCV debate. Good enough for forced induction then good enough for us old N/A motors too...
Is the NRE 5th gen running a MAF?
You don't have a NRE 5th gen, you have an N/A LS1, the PCV WILL BE DIFFERENT, big power FI builds require different systems ideally than NA engines. RACE engines are different from STREET engines. Would you run a cam made for big power FI build on an NA engine? But its good enough for high hp FI it should be good enough for NA right? - same logic as you.
You can remove the PCV system all together if you want, but your oil will need to be changed more frequently as it will get dirty much quicker - the whole point of the PCV system is to keep the crankcase more clean.
Ill try to explain again, try to read carefully.
Keep the catch can the way it is. Remove the T-fitting on the clean line, its not needed. Run the clean line like it is in the stock location, from the passenger side valve cover to the throttle body, only this time with a one-way check valve in it. The check valve will let air come from the throttle body into the valve cover but not let air/oil vapor come from the valve cover to throttle body - that is likely where you are getting oil from. Then you replace your oil cap with a specific breather, one that has a check valve built in to let air out of the valve cover but not back in. This way any excess pressure that would normally shoot up the clean line into your throttle body is now being stopped by the check valve in the clean line and being released through the breather instead. But the breather will not let any air back into the system that would cause a vacuum leak condition on a MAF car. If the car doesn't run a MAF then that is a different story and things can be setup differently.
JD,
Thanks for clearing this up for me and it sounds like a solid solution to my oiling problem. I've seen first hand and I'm sure you have also as to the affects of running a "STREET LEGAL" pcv system which introduces oil vapor back into the air/fuel mixture to be reignited and pushed out the exhaust pipes.
Lets get some things straight here.
Is the NRE 5th gen running a MAF?
You don't have a NRE 5th gen, you have an N/A LS1, the PCV WILL BE DIFFERENT, big power FI builds require different systems ideally than NA engines. RACE engines are different from STREET engines. Would you run a cam made for big power FI build on an NA engine? But its good enough for high hp FI it should be good enough for NA right? - same logic as you.
You can remove the PCV system all together if you want, but your oil will need to be changed more frequently as it will get dirty much quicker - the whole point of the PCV system is to keep the crankcase more clean.
Keep the catch can the way it is. Remove the T-fitting on the clean line, its not needed. Run the clean line like it is in the stock location, from the passenger side valve cover to the throttle body, only this time with a one-way check valve in it. The check valve will let air come from the throttle body into the valve cover but not let air/oil vapor come from the valve cover to throttle body - that is likely where you are getting oil from. Then you replace your oil cap with a specific breather, one that has a check valve built in to let air out of the valve cover but not back in. This way any excess pressure that would normally shoot up the clean line into your throttle body is now being stopped by the check valve in the clean line and being released through the breather instead. But the breather will not let any air back into the system that would cause a vacuum leak condition on a MAF car. If the car doesn't run a MAF then that is a different story and things can be setup differently.
JD,
Thanks for clearing this up for me and it sounds like a solid solution to my oiling problem. I've seen first hand and I'm sure you have also as to the affects of running a "STREET LEGAL" pcv system which introduces oil vapor back into the air/fuel mixture to be reignited and pushed out the exhaust pipes.
Lets get some things straight here.
Is the NRE 5th gen running a MAF?
You don't have a NRE 5th gen, you have an N/A LS1, the PCV WILL BE DIFFERENT, big power FI builds require different systems ideally than NA engines. RACE engines are different from STREET engines. Would you run a cam made for big power FI build on an NA engine? But its good enough for high hp FI it should be good enough for NA right? - same logic as you.
You can remove the PCV system all together if you want, but your oil will need to be changed more frequently as it will get dirty much quicker - the whole point of the PCV system is to keep the crankcase more clean.