Girly Catch Can Mounted
#85
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Ok, so... Thinking about the catch can thing, I've never really come up with something I like.
I assume, idealy,
1) the valve cover always has flow through it.
2) the best place for those fumes is the intake manifold
3) a catch can is needed between valve cover and "vent to atmosphere"
And two things I'd like to see, but am not so sure on:
4) A catch can on BOTH manifold vents is best
5) venting to the air cleaner is better than to the atmosphere
Anyway, here's a couple things I was looking for:
![](http://abefm.smugmug.com/photos/335866155_sXAkz-XL.png)
From 4) above I think two cans is what I want. And the problem with Method #1 is that it doesn't follow 1) above.
Anyway... I'm curious about people's thoughts.
I assume, idealy,
1) the valve cover always has flow through it.
2) the best place for those fumes is the intake manifold
3) a catch can is needed between valve cover and "vent to atmosphere"
And two things I'd like to see, but am not so sure on:
4) A catch can on BOTH manifold vents is best
5) venting to the air cleaner is better than to the atmosphere
Anyway, here's a couple things I was looking for:
![](http://abefm.smugmug.com/photos/335866155_sXAkz-XL.png)
From 4) above I think two cans is what I want. And the problem with Method #1 is that it doesn't follow 1) above.
Anyway... I'm curious about people's thoughts.
#88
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Abe, based upon your ideas/contributions, I made this beauty (I think it's like your first example):![](http://i258.photobucket.com/albums/hh273/henarot/vent.jpg)
If manifold vacuum is present, then we'd see crankcase gas evacuation. Win.
In boost, the manifold would be safely sealed AND crankcase gasses would have the ability to VTA. Win and Win.
However, one problem I see right away (in boost) is that the crankcase gases must overcome the resistance in check valve #2, which, depending on check valve design, would possibly result in "high" pressure in the crankcase.
![](http://i258.photobucket.com/albums/hh273/henarot/vent.jpg)
If manifold vacuum is present, then we'd see crankcase gas evacuation. Win.
In boost, the manifold would be safely sealed AND crankcase gasses would have the ability to VTA. Win and Win.
However, one problem I see right away (in boost) is that the crankcase gases must overcome the resistance in check valve #2, which, depending on check valve design, would possibly result in "high" pressure in the crankcase.
#90
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i fail to see the need for two check valves....
youll still want the pcv.... or straight up **** anythign running to the IM.
try this. gut your PCV and try to idle the car, **** will run like ******* with the big as vacuum leak you've created.
so a pcv like normal will prevent that, and allow the fumes to be burnt off like a good boy. the check valve will prevent any boost from entering the catch can or crankcase....meanwhile to crankcase will be open to atmosphere through two ports....
youll still want the pcv.... or straight up **** anythign running to the IM.
try this. gut your PCV and try to idle the car, **** will run like ******* with the big as vacuum leak you've created.
so a pcv like normal will prevent that, and allow the fumes to be burnt off like a good boy. the check valve will prevent any boost from entering the catch can or crankcase....meanwhile to crankcase will be open to atmosphere through two ports....
#91
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i fail to see the need for two check valves....
youll still want the pcv.... or straight up **** anythign running to the IM.
try this. gut your PCV and try to idle the car, **** will run like ******* with the big as vacuum leak you've created.
so a pcv like normal will prevent that, and allow the fumes to be burnt off like a good boy. the check valve will prevent any boost from entering the catch can or crankcase....meanwhile to crankcase will be open to atmosphere through two ports....
youll still want the pcv.... or straight up **** anythign running to the IM.
try this. gut your PCV and try to idle the car, **** will run like ******* with the big as vacuum leak you've created.
so a pcv like normal will prevent that, and allow the fumes to be burnt off like a good boy. the check valve will prevent any boost from entering the catch can or crankcase....meanwhile to crankcase will be open to atmosphere through two ports....
Anyway, to the actual point, yes, you'll have a vacuum leak if you just let the mani see the atmosphere through the catch can and the crankcase. Is it enough to be a problem? I dunno. But that's why I have the checkvalve, so that under vacuum there's no leak.
I'm just hoping the check valve to atmosphere doens't have a lot of resistance... And I'm hoping that not flowing air through the valve cover is ok.
I think the issue with no cross flow is you're not really flushing out all the moisture you could be, which translates to oil that doesn't last as long. So far all my best ideas involve way too many catch cans. :-) I guess under boost you can live without cross flow.
#93
Boost Czar
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Anyway, to the actual point, yes, you'll have a vacuum leak if you just let the mani see the atmosphere through the catch can and the crankcase. Is it enough to be a problem? I dunno. But that's why I have the checkvalve, so that under vacuum there's no leak.
#94
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Um, are you claiming there's some difference between a "PCV" and a check valve?
The idea is so the manifold can suck on the catch can (and therefor the valve cover) but not suck from atmosphere (which I'm undecided if it's a good idea), nor can boost pressure blow into the crank case. Hence the two check valves.
The idea is so the manifold can suck on the catch can (and therefor the valve cover) but not suck from atmosphere (which I'm undecided if it's a good idea), nor can boost pressure blow into the crank case. Hence the two check valves.
#97
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hmm. i'm following this thread a bit more closely now. went out for a spirited run with a lot of high end cars on saturday, and it involved a lot of running at high rpm and a couple extra pounds of boost. by the end of a couple hours drive, i was producing a good amount of oil smoke from my tailpipe (at least half a dozen people made sure to mention the car was smoking pretty good...).
when i finally popped the hood after getting home, there was oil everywhere that it could possibly get to from the breather on the driver's side of the motor. popped the hose off the PCV and there was oil all in and around that as well...
question is, think running a double vented catch can like the original post, and plugging the IM port solve my issue for now (assuming i haven't done the rings in?) while i wait for a couple of those fancy check valves to come in the mail?
when i finally popped the hood after getting home, there was oil everywhere that it could possibly get to from the breather on the driver's side of the motor. popped the hose off the PCV and there was oil all in and around that as well...
question is, think running a double vented catch can like the original post, and plugging the IM port solve my issue for now (assuming i haven't done the rings in?) while i wait for a couple of those fancy check valves to come in the mail?
#98
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I doubt you harmed the rings, at least, not from the oil directly, but I guess potentially from detonation if the oil coated the intercooler and/or diluted your octane rating significantly.