Is the Catch Can necessary
Pro
Joined: Nov 2013
Posts: 693
Likes: 158
From: Milwaukee WI
Talking about what other manufacturers do to keep oil out of the intake is completely relevant to this thread. God knows I don't want to turn this into yet another Porsche thread, which is why I mentioned three other manufacturers using air oil separators. There are more. Your opinion is yours, not necessarily mine. If your not interested in what other manufacturers are doing to address the problem, don't respond to those posts. I'd say it's more than a little amusing.
Thread Starter
Racer
Joined: Jul 2010
Posts: 392
Likes: 3
From: Palm Coast Florida
Talking about what other manufacturers do to keep oil out of the intake is completely relevant to this thread. God knows I don't want to turn this into yet another Porsche thread, which is why I mentioned three other manufacturers using air oil separators. There are more. Your opinion is yours, not necessarily mine. If your not interested in what other manufacturers are doing to address the problem, don't respond to those posts. I'd say it's more than a little amusing.
Race Director
Joined: Jul 2007
Posts: 10,961
Likes: 2,643
From: Texas Hill Country
Talking about what other manufacturers do to keep oil out of the intake is completely relevant to this thread. God knows I don't want to turn this into yet another Porsche thread, which is why I mentioned three other manufacturers using air oil separators. There are more. Your opinion is yours, not necessarily mine. If your not interested in what other manufacturers are doing to address the problem, don't respond to those posts. I'd say it's more than a little amusing.
you are saying that since porsche uses Method S instead of Method P then it makes sense to supplement Method P with Addendum C, which is of course, preposterous.
especially when the porsche system is not used to "address the problem" of oily intake valves, because it doesn't work, obviously. the porsche system is there to perform the same function as the chevy pcv system, which also isn't 100% oil proof. so the porsche system is no more effective than the chevy system and therefore cannot possibly be contributory to the catch can discussion.
Le Mans Master
Joined: Jul 2001
Posts: 8,071
Likes: 317
From: Central Florida
Thread Starter
Racer
Joined: Jul 2010
Posts: 392
Likes: 3
From: Palm Coast Florida
OP, Catch can or no catch can, I really don't care, but I don't want oil from the PVC entering the intake and coking my valves. If anyone has a better method I would sure like to know. This is not only a problem with GM, but every direct injection engine. If you think this condition doesn't exist you have the right to ignore it.
Race Director
Joined: Jul 2007
Posts: 10,961
Likes: 2,643
From: Texas Hill Country
OP, Catch can or no catch can, I really don't care, but I don't want oil from the PVC entering the intake and coking my valves. If anyone has a better method I would sure like to know. This is not only a problem with GM, but every direct injection engine. If you think this condition doesn't exist you have the right to ignore it.
Drifting
Joined: Jan 2005
Posts: 1,949
Likes: 1,336
From: Houston Tx
the condition exists and if I have said it once I've said it 4 times......the only way to keep the valves and intake clean is to remove the pcv system and vent to atmosphere through a filter which can cause condensation and poopy contamination in the crankcase or use a vacuum pump which will keep your crankcase squeaky clean and can give a 15-30 hp bump (no joke) except it costs way more and isn't available yet as a kit for the C7.
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Race Director
Joined: Jul 2007
Posts: 10,961
Likes: 2,643
From: Texas Hill Country
Which as I’ve said a couple of times is illegal, because it makes your car pollute as much as about 50 properly controlled cars. We really are getting redundant here, but at least this time I won’t make the error of saying you are advocating that move. You are simply saying that it’s possible. Now you can call me a weenie again for saying that move would be irresponsible, all in good fun of course.
so the real end of the discussion answer is there is no way to prevent oil from entering the intake manifold from the pcv system unless you illegally modify the system. you can waste money on band aids but they will only fall off in the pool and gross everyone out.
Melting Slicks
Joined: Jun 2005
Posts: 2,216
Likes: 1
St. Jude Donor '12-'13-'14, '16
OP, Catch can or no catch can, I really don't care, but I don't want oil from the PVC entering the intake and coking my valves. If anyone has a better method I would sure like to know. This is not only a problem with GM, but every direct injection engine. If you think this condition doesn't exist you have the right to ignore it.
...The 2015 Lamborghini Huracan uses direct injection plus port injection and an air oil separator..
..they say they are doing the duel injection for power and emissions but I wonder if will have the benefit of keeping the intake valves clean.http://r.search.yahoo.com/_ylt=A0SO8...zQyFyWe3EMPyA-
Thread Starter
Racer
Joined: Jul 2010
Posts: 392
Likes: 3
From: Palm Coast Florida
Your aware of the problem and I'll just bet you change your mind down the road. GM didn't invent the Direct injection theory they just ran with a great idea. That being said, I think they did a great job with this car. This is my 15th Corvette and it is the very best.
Thread Starter
Racer
Joined: Jul 2010
Posts: 392
Likes: 3
From: Palm Coast Florida
The only complete cure is to install a vacuum pump and a catch can. That will completely eliminate any oil entering the manifold. Eventually this will be G M cure and have the excess oil drain back into the oil pan or dry sump system. If the catch can manufacturers are reading this they know I am absolutely correct, make it they will come.
Le Mans Master
Joined: Jun 2000
Posts: 5,555
Likes: 9
From: Indiana
Seems like an oil separator could be used to extract the oil, but instead of passing it thru the intake valve, why not inject it with the fuel, directly into the cylinder .. so you still combust the crankcase vapors, but don't pass the oil over the intake valve?
Just trying to think outside the box ..
Just trying to think outside the box ..
Thread Starter
Racer
Joined: Jul 2010
Posts: 392
Likes: 3
From: Palm Coast Florida
Seems like an oil separator could be used to extract the oil, but instead of passing it thru the intake valve, why not inject it with the fuel, directly into the cylinder .. so you still combust the crankcase vapors, but don't pass the oil over the intake valve?
Just trying to think outside the box ..
Just trying to think outside the box ..
Safety Car
Joined: Sep 2000
Posts: 3,604
Likes: 396
From: Austin, TX
If you have a Z51 pull your air bridge and filter and see what is in there. You may be unpleasantly surprised. I had oil puddled in there at ~1500 miles with normal break in.
99% sure the sump tank is burping as that pcv hose is very oily.
We'll see what it looks like at the next oil change.
99% sure the sump tank is burping as that pcv hose is very oily.
We'll see what it looks like at the next oil change.
Team Owner
Joined: Jul 2006
Posts: 97,155
Likes: 1,471
From: Calgary, AB. There's a reason why white was the only color offered on every year Corvette. Proud Canadian German Jamaican!
St. Jude Donor '09, '12-'13-'14-'15-'16-'17
I'm thinking that if a catch can was really needed, an extra $100 cost of adding it while the engine was on the production line GM would've done it already. I'm not going to second guess the engine engineers at GM, I think they know what they're doing.
Race Director
Joined: Sep 2013
Posts: 11,825
Likes: 2,477
From: Ft Lauderdale
Tech Contributor
Yup...installed one, then got about a tsp per 1000 miles, read the criswell article, took it off and sold it. I think gm is not stupid in this regard.
Last edited by Glen e; Jan 29, 2015 at 11:38 AM.
