So...you don't feel a Catch Can is necessary in a Wet Sump car?!? Check this out
02-07-2015, 10:52 PM
#41
Le Mans Master
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St. Jude Donor '13-'14-'15
I was told by a very reputable shop not to run valve cover breathers.All I can tell you is looking at the photos of the intake valves on a STOCK LT1 looks horrible---The oil intrusion is terrible--Moving the vent closer and restriction free will only aid in reducing oil injestion via
the PCV system by increasing crankcase vacuum----A catch can is also mandatory to compliment the beathers----
02-08-2015, 12:20 AM
#42
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Unmetered air ?? Where ?? NO there is No unmetered air coming into the engine anywhere !! If you looked at the photos the stock PCV inlet tubes are capped off--- There is NO WAY unmetered air is getting into the intake---Using atmospheric valve cover breathers totally isolates the PCV system from the air box---makes no sense what you are saying---
You said " you are just pulling air through the crankcase into your intake manifold from the filters. bad idea."
Show me where I am introducing unmetered air into the intake manifold---All that valve cover breathers do is re- locate the breather location from the captured air box to atmosphere --where there is NO restriction---Even in the stock location there cannot be any unmetered air so there cannot be by relocating the breathers anywhere----
Maybe in previous C5 or C6 engines where the PCV was vented to the "T-Body" post MAF -- YES you could get unmetered air by running breathers---But the LT1 has moved the PCV vent from the T-Body ( post MAF) to the air box ( Pre MAF)---There is NO change in metered air when the vent is in the air box OR anywhwere's else other than the T-Body as in the C5 or C6--- Main reason GM moved the vent from the T-Body to the air box---However this may have eliminated injestion of unmetered air--it also added more restriction to the vent side of the PCV system---
You said " you are just pulling air through the crankcase into your intake manifold from the filters. bad idea."
Show me where I am introducing unmetered air into the intake manifold---All that valve cover breathers do is re- locate the breather location from the captured air box to atmosphere --where there is NO restriction---Even in the stock location there cannot be any unmetered air so there cannot be by relocating the breathers anywhere----
Maybe in previous C5 or C6 engines where the PCV was vented to the "T-Body" post MAF -- YES you could get unmetered air by running breathers---But the LT1 has moved the PCV vent from the T-Body ( post MAF) to the air box ( Pre MAF)---There is NO change in metered air when the vent is in the air box OR anywhwere's else other than the T-Body as in the C5 or C6--- Main reason GM moved the vent from the T-Body to the air box---However this may have eliminated injestion of unmetered air--it also added more restriction to the vent side of the PCV system---
On a C5 or C6 where the PCV was vented to the T-body--YES you would have to make a slight change in your MAF table to compensate for the relocation of the PCV vent----HOWEVER the LT1 GM moved the PCV vent from the T-body to the air box----This totally isolates the PVC system from the engine airflow---So valve cover breathers have NO affect on engine metered airflow----
All I can tell you is looking at the photos of the intake valves on a STOCK LT1 looks horrible---The oil intrusion is terrible--Moving the vent closer and restriction free will only aid in reducing oil injestion via
the PCV system by increasing crankcase vacuum----A catch can is also mandatory to compliment the beathers----
All I can tell you is looking at the photos of the intake valves on a STOCK LT1 looks horrible---The oil intrusion is terrible--Moving the vent closer and restriction free will only aid in reducing oil injestion via
the PCV system by increasing crankcase vacuum----A catch can is also mandatory to compliment the beathers----
I don't think you know how a PCV system works at all.....Look where your MAF sensor is located, down near the air filter housing. Now look where the PCV fresh air lines are located on your intake tube. AFTER THE MAF.
The intake manifold vacuum pulls air into the inlet behind the throttle body from the valley outlet under the manifold which is the same body of air as the crankcase/oil drains/valve cover/oil fill hole, etc.
When this air is removed from the crankcase it must be replaced with fresh air or else it will just create a vacuum in the crankcase and flow will cease.
Where does this air come from? From the INLET on the valve covers, which gets its air FROM the tubes connecting to the airbox (that you have capped off and replaced with open filters).
The nipples on the airbox (air inlet tube actually) are POST MAF in every car on the planet and has nothing to do with a T-line.
Therefore, replacing your METERED FRESH CRANKCASE PCV AIR with open filters mean you are indeed using unmetered air to replace your crankcase air that is being pulled through the PCV system into the intake manifold which then goes through the combustion process.
The only time your breather filters are used as vents in the opposite direction are when you go WOT and there is no vacuum in the intake manifold to pull crankcase air through but the WOT condition creates enough crankcase pressure to push backwards through the filters.
And THAT is why you should STOP POSTING about anything other than "what wax should I use on my car" threads. You DO NOT have a clue (once again).
I cant even imagine what it must be like to be wrong every time you post (remember, you asked for it).
02-08-2015, 09:58 AM
#43
Burning Brakes
Not sure if I mentioned it earlier but luckily my intake tube, filter, and throttle body were dry. The inside of the manifold and heads/valves were the only things that were gunked up. These are very interesting videos. I do wonder how safe it is to try and clean the valves with a wire brush on a drill though. One bristle comes off and get into the engine and that'll be all she wrote. Also this was done on a dry sump but I assume the premise is all the same either way. Either way though I need to do something here. So what can we do as more of a permanent solution to the PCV issue? Is capping off the valley cover and intake manifold ports a possibility? Or at that point would you basically be redirecting the same issue elsewhere..?
I'm curious. How many miles were on your C7 before you installed your Catch Can?
02-08-2015, 10:08 AM
#44
Melting Slicks
Fyreant, looking back in the first picture of your catch can seems it is completely full you may have tricked yourself a little bit in this case on the intake manifold inspection still being wet with oil. once the can is full or as it approaches full it's going to be doing a worse and worse job of catching the oil, until it completely bypasses. I think you would have better results on the visual inspection if you had more recently dumped the can. Maybe a larger catch can next time?
02-08-2015, 10:19 AM
#45
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I've seen video's of a wire brush attachment for a drill (could be a special wire brush specifically made for this purpose?) to clean the intake area and also heard some use a tool that air blasts an abrasive material (such as crushed walnut shells) to clean the intake port area. Rx Performance Products at (941) 721-1826 should be able to steer you to the right tool.
I'm curious. How many miles were on your C7 before you installed your Catch Can?
I'm curious. How many miles were on your C7 before you installed your Catch Can?
Fyreant, looking back in the first picture of your catch can seems it is completely full you may have tricked yourself a little bit in this case on the intake manifold inspection still being wet with oil. once the can is full or as it approaches full it's going to be doing a worse and worse job of catching the oil, until it completely bypasses. I think you would have better results on the visual inspection if you had more recently dumped the can. Maybe a larger catch can next time?
Any thoughts guys on how to clean the oily film from the inside of the intake manifold? Am I ok to use non-chlorinated brakleen or could that eat into the plastic?
02-08-2015, 11:19 AM
#46
Heel & Toe
What is in the can?
Pour it out into a glass container and see what it looks like. I got 6 ounces in mine (see picture below) after 3500 miles but it wasn't oil really, maybe some oil, but not "just" oil. I put the Elite Engineering best on at 1200 miles after the first oil change and I'm going to empty mine every 5000 miles as if I go much longer than that it might fill up completely. I'm surely not sorry I got one as I don't want that stuff going through my engine.
Last edited by ntonkin; 02-09-2015 at 08:17 PM. Reason: Add photo
02-09-2015, 12:23 AM
#47
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ok so I decided that I wasn't going to let my time go to waste after taking the intake manifold off, so I went ahead and did a valve cleaning just like in the video Rave posted on page 2. here is a before and after shot of one of the valves (all the rest look pretty similar to the second image now). I also sprayed a boatload of brake cleaner into the intake manifold, and let all the oily residue drain out. I've already got the car back together and she seems to be running fine again at this point..
Ant
Ant
02-09-2015, 01:48 AM
#48
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Wow looks a lot better. But let me tell you.. I'm a race type of guy and in any race I may lose because of this/airflow. Anyone wants to think different that's ok. The build up on those valves is NOT good for any kind of racing.. Over time.. A problem or 2 for sure.
I'm
Not putting down anything including buying a C7. I bought one 2 months ago for my wife and I'm 3 days buying another and having two !
I'm
Not putting down anything including buying a C7. I bought one 2 months ago for my wife and I'm 3 days buying another and having two !
02-10-2015, 11:12 PM
#49
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Wow looks a lot better. But let me tell you.. I'm a race type of guy and in any race I may lose because of this/airflow. Anyone wants to think different that's ok. The build up on those valves is NOT good for any kind of racing.. Over time.. A problem or 2 for sure.
I'm
Not putting down anything including buying a C7. I bought one 2 months ago for my wife and I'm 3 days buying another and having two !
I'm
Not putting down anything including buying a C7. I bought one 2 months ago for my wife and I'm 3 days buying another and having two !
02-11-2015, 07:14 AM
#50
Melting Slicks
I pulled my air cleaner assembly ahead of the throttle body off last night. No oil residue on the throttle body or intake tube. None.
I have 8300 miles and drive it fairly hard on the street.
I pulled it at 3000 miles and there was a puddle of oil where the PCV tube connects and goes back to the dry sump tank. The oil was overfilled and likely burped into the intake tube. Maybe it was also due to the anti foaming additive issue and the new requirement to change the oil after the first 500 miles. I changed mine for the first time after 2800.
As to the OP issue, its not normal.
I have 8300 miles and drive it fairly hard on the street.
I pulled it at 3000 miles and there was a puddle of oil where the PCV tube connects and goes back to the dry sump tank. The oil was overfilled and likely burped into the intake tube. Maybe it was also due to the anti foaming additive issue and the new requirement to change the oil after the first 500 miles. I changed mine for the first time after 2800.
As to the OP issue, its not normal.
02-11-2015, 02:16 PM
#53
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drink from your swimming pool with a 4 inch diameter pipe....not easy.
02-12-2015, 11:50 AM
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i have seen no oil pushed through the intake tube on a wet sump (the dry sump has the overfill burp issue but that is not the same thing). the C5s and C6s would push oil into the intake tube at wot through the valve covers. they would suck oil into the intake manifold at part throttle from the valley.
02-12-2015, 12:04 PM
#56
You can make the tube on the valve cover as big as the cover its self. When you put the factory quick disconnect fitting on it the orifice in the fitting is the size of a small straw. Also if the engine really needs to vent the check ***** they have in those fittings can close completely forcing all the venting through the valley pan on a wet sump car and also through the port on the PS valve cover if its a dry sump car. This is likely the situation that causes some cars dump the dry sump tank into the air inlet plenum besides the fact that the pump occasionally pumps air along with oil into the tank.
This is as I have said before is an industry wide problem that is not just a GM issue let alone a C7 one. Domestic and foreign are having issues also. An on going problem that has not gotten necessarily worse but is much more critical since engines have gone to direct injection.
This is as I have said before is an industry wide problem that is not just a GM issue let alone a C7 one. Domestic and foreign are having issues also. An on going problem that has not gotten necessarily worse but is much more critical since engines have gone to direct injection.
02-12-2015, 12:06 PM
#57
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You can make the tube on the valve cover as big as the cover its self. When you put the factory quick disconnect fitting on it the orifice in the fitting is the size of a small straw. Also if the engine really needs to vent the check ***** they have in those fittings can close completely forcing all the venting through the valley pan on a wet sump car and also through the port on the PS valve cover if its a dry sump car. This is likely the situation that causes some cars dump the dry sump tank into the air inlet plenum besides the fact that the pump occasionally pumps air along with oil into the tank.
This is as I have said before is an industry wide problem that is not just a GM issue let alone a C7 one. Domestic and foreign are having issues also. An on going problem that has not gotten necessarily worse but is much more critical since engines have gone to direct injection.
This is as I have said before is an industry wide problem that is not just a GM issue let alone a C7 one. Domestic and foreign are having issues also. An on going problem that has not gotten necessarily worse but is much more critical since engines have gone to direct injection.
02-12-2015, 02:27 PM
#58
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How can I check the PCV lines to ensure if the check ***** are stuck or not? Do I just use my mouth and blow through the line and see if it's stuck or is there a better method to test. Also, what about removing the check ***** altogether? Is that a possibility?
02-12-2015, 02:48 PM
#59
Page 40 shows how to remove them and I would suggest that. There is one on each side
02-21-2015, 06:27 PM
#60
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Ok so I took my car in for the routine oil change and decided that it would be best to do another oil consumption test. I'm going to keep close tabs on my oil level to see if indeed we can prove excess oil consumption is occurring.