Oil Catch Can
- Thread starter Riderfan
- Start date
Absolutely a necessity on a LS engine in my opinion! I have one and swear by it. The amount of oil it catches from going into the intake is astonishing. I don't recall what make mine is, but they're all pretty similar. 
Yes, I put one on all of my cars. They do work and I empty at least at every oil change. It is not surprising to get an ounce or more of sludge that would have gone into the intake. There are various ones on the market. This video shows the Elite Engineering unit (which imho has the best mounting technique and easy to empty)
I opted to buy a less expensive one on eBay and will make my own mount.
I opted to buy a less expensive one on eBay and will make my own mount.
I've got a Mighty Mouse set up. It's very slick, installs quite easily, easy to drain and looks sharp. They aren't cheap but nothing worth owning is.
https://www.mightymousesolutions.com
https://www.mightymousesolutions.com
Yes, if you look at his past videos there are a few gems in there. I'm planning to change the cam in my 03 so I took note of what he did when he tore his engine apart.
Absolutely agree on the importance of a catch can. The PCV systems on modern engines are simply too short, and with the high compression and higher revving engines, it is inevitable that your engine is going to consume oil. I had to argue with the guys who built my engine because they insisted that a naturally-aspirated engine didn't need one, and I told 'em I don't care, I want one anyway. I went with the Elite, and after only two weeks on a brand-new engine, I found more than a quarter cup of oil in the can. Go ahead and tell me again that these things are not needed.
There are many different ones available on the market. Get one that has good screens, preferably two. Get the screw-type that allows you to empty the can yourself so that you can see how much it is catching, and dispose of it properly. I have another one that has a hose that comes off the bottom of the can and just empties itself underneath the car, and this is awful. Don't do this. It makes a mess of the bottom of the car, your garage floor or driveway, and it is environmentally irresponsible. I have blocked mine off, but it is a real pain to remove the can from the bracket just to empty it. I will replace it with another Elite.
For all you C7 guys reading this, and especially those of you with Z06s or ZR1s, you especially need a catch can. Two, even. Don't laugh. Don't shake your head. Don't bother asking your dealer, because they don't know. Ask anyone who has a catch can. Do they work? Yes. Yes, they sure do.
There are many different ones available on the market. Get one that has good screens, preferably two. Get the screw-type that allows you to empty the can yourself so that you can see how much it is catching, and dispose of it properly. I have another one that has a hose that comes off the bottom of the can and just empties itself underneath the car, and this is awful. Don't do this. It makes a mess of the bottom of the car, your garage floor or driveway, and it is environmentally irresponsible. I have blocked mine off, but it is a real pain to remove the can from the bracket just to empty it. I will replace it with another Elite.
For all you C7 guys reading this, and especially those of you with Z06s or ZR1s, you especially need a catch can. Two, even. Don't laugh. Don't shake your head. Don't bother asking your dealer, because they don't know. Ask anyone who has a catch can. Do they work? Yes. Yes, they sure do.
I installed a Mike Norris can two years ago. Black anodized, and the mounting bracket is beautifully executed. I log about 2 to 3k a season, so one oil change, at the end of each season. I get about 2 to 3 tablespoons of oil out of it. Say 1 tablespoon per 1000km's Better there, than in the intake. I empty it from the bottom. I cut the bottom off a plastic fruit drink container, and it slips in underneath, between the petcock and the frame. Drain it, pull it out, dispose of the oil, and clean it with some brake cleaner. See you next year.
BTW... the little filter pads in them are nothing more than die cut pieces of 3M Scotch Brite pad.
BTW... the little filter pads in them are nothing more than die cut pieces of 3M Scotch Brite pad.
Well crap, I thought because my C5 looks to use no oil, when I check the dipstick, I didn't need one. Now I am going to google Elite.
I believe the theory is that this oil vapor will just get burnt up along with the clean air coming from the throttle body. I first used a catch can on a super charged engine because I did not want that gunk messing with the rotors. I also have a GDI engine that is my daily driver and they recommend a catch can for those because with this type of fuel injection the intake valves don't get cleaned by the fuel (like port injection in our engines). I'm putting a catch can on my LS6 because I want to keep the intake internals as clean as I can even though it may be fine without it. I believe the factory does not install them is because that would be another maintenance item that would have to be checked/emptied. I care about my vehicles and do my own maintenance so I don't mind.
Whatever the engineering principles are behind the design of modern engines in general, the PCV systems are inefficient in most applications, typically because they want to use less materials and lower their costs. I personally think that every car needs a catch can, but performance cars need them even more.
I will try to explain the way this works in a simple way. It is not meant to be an engineer-type of explanation, so please forgive me for my simplicity.
We all know the basic premise of how our engine works, right? Suck, squeeze, bang, blow - that's what makes my engine go. So basically, when your piston draws air in, the underside of the piston also pushes air down. There is also varying levels of fuel and vapors that get sucked past the piston rings, and this creates pressure in the oilpan, which can push back on the pistons when you are trying to make power. In order to reduce this pressure, the PCV (positive crankcase ventilation) system is designed to let this pressure out of the engine, so that it doesn't interfere.
Now, there are a few ways to deal with the pressure that is coming through this PCV system. The simplest is to just allow it to vent to atmosphere. But this will cause oil stains and greasy bits all over your engine bay, and that is not cool.
You can do a simple filter plug in the valve cover, which is a very common solution on many small blocks of the 70's and 80's.
The way that modern cars have done it for many years is that they run a rubber hose from the valve cover back into the air intake, and that way the unburned fuel and vapors from the engine can get recirculated and burned again, essentially.
The trouble is, it isn't just gas and vapors that run through that rubber hose. It is anything that gets sucked into that pressure. And oil is a major factor. Oil is constantly thrashing about in your engine and particles of it are flying everywhere at any time that you engine is running. Therefore, it is reasonable to think that airflow is going to suck up some particles along the way. The more pressure (via the gas pedal), the more the chances that bigger particles of oil are going to get sucked up.
The idea of the system is pretty simple. It's a reverse-straw, really. If you put a straw at the top of the engine, it is reasonable to expect that the pressure will only push out air, because it is the lightest thing. But as any child who has ever finished a McDonald's milkshake and wanted more will know, if you suck harder, you will get a tiny bit more. This is what your engine is doing.
High compression and high revs mean that the pressure will push oil up into the PCV hose. It won't take long before your PCV valve or filter is saturated, and simply can't hold the oil any more, at which point it simply particulates into the air and goes right into your intake, where it gums up your airflow sensor, coats the inside of your intake manifold, your valve seals, and ultimately, into your combustion chamber where it burns and comes out of your exhaust as smoke. If your tailpipes are black, then this is happening to you.
A catch can is a pretty simple thing too. Instead of coming out of the valve cover and right back into the air inlet, they should be designed to be a bit uphill and a longer run to get to a can where the air comes in from the top, passes through a screen or two (to break up the oil and slow it down), and then exits back out the top on a separate line. The oil cannot make the 180 degree turn, but the air can.
If you have a forced induction car, please read again the part about the milkshake. If you suck harder, it will.... uh..... require two catch cans.
Seriously. Get one. At your next oil change you will see what I mean, and you will thank me.
I will try to explain the way this works in a simple way. It is not meant to be an engineer-type of explanation, so please forgive me for my simplicity.
We all know the basic premise of how our engine works, right? Suck, squeeze, bang, blow - that's what makes my engine go. So basically, when your piston draws air in, the underside of the piston also pushes air down. There is also varying levels of fuel and vapors that get sucked past the piston rings, and this creates pressure in the oilpan, which can push back on the pistons when you are trying to make power. In order to reduce this pressure, the PCV (positive crankcase ventilation) system is designed to let this pressure out of the engine, so that it doesn't interfere.
Now, there are a few ways to deal with the pressure that is coming through this PCV system. The simplest is to just allow it to vent to atmosphere. But this will cause oil stains and greasy bits all over your engine bay, and that is not cool.
You can do a simple filter plug in the valve cover, which is a very common solution on many small blocks of the 70's and 80's.
The way that modern cars have done it for many years is that they run a rubber hose from the valve cover back into the air intake, and that way the unburned fuel and vapors from the engine can get recirculated and burned again, essentially.
The trouble is, it isn't just gas and vapors that run through that rubber hose. It is anything that gets sucked into that pressure. And oil is a major factor. Oil is constantly thrashing about in your engine and particles of it are flying everywhere at any time that you engine is running. Therefore, it is reasonable to think that airflow is going to suck up some particles along the way. The more pressure (via the gas pedal), the more the chances that bigger particles of oil are going to get sucked up.
The idea of the system is pretty simple. It's a reverse-straw, really. If you put a straw at the top of the engine, it is reasonable to expect that the pressure will only push out air, because it is the lightest thing. But as any child who has ever finished a McDonald's milkshake and wanted more will know, if you suck harder, you will get a tiny bit more. This is what your engine is doing.
High compression and high revs mean that the pressure will push oil up into the PCV hose. It won't take long before your PCV valve or filter is saturated, and simply can't hold the oil any more, at which point it simply particulates into the air and goes right into your intake, where it gums up your airflow sensor, coats the inside of your intake manifold, your valve seals, and ultimately, into your combustion chamber where it burns and comes out of your exhaust as smoke. If your tailpipes are black, then this is happening to you.
A catch can is a pretty simple thing too. Instead of coming out of the valve cover and right back into the air inlet, they should be designed to be a bit uphill and a longer run to get to a can where the air comes in from the top, passes through a screen or two (to break up the oil and slow it down), and then exits back out the top on a separate line. The oil cannot make the 180 degree turn, but the air can.
If you have a forced induction car, please read again the part about the milkshake. If you suck harder, it will.... uh..... require two catch cans.
Seriously. Get one. At your next oil change you will see what I mean, and you will thank me.
Hell I’ll thank you now. 
That was a great explanation and I happened to have a very knowledgeable Auzzie mechanic sitting right beside me that gave your post a
Only problem is now I want a McDs milkshake and I’m way the hell offshore
That was a great explanation and I happened to have a very knowledgeable Auzzie mechanic sitting right beside me that gave your post a
Only problem is now I want a McDs milkshake and I’m way the hell offshore
Thanks for taking the time to spell it out for us. It has been a long time since I really thought about it all. Never been explained better than that. And the 'suck, squeeze ,bang, blow' part I will never forget. 
I checked out Elite and MightyMouse but they only sell kits for C5 &C6.
The Mike Norris site doesn't shows kits.
I guess I would need to buy the necessary hoses to incorporate the "Motorsports Billet PCV Oil Catch Can"?
Thanks for your advice!
Not that I know anything about catch cans, but I do remember an earlier post
By Dave at Race Ready Garage with his product. He is a forum sponsor with a good rep if you wanted to check him out. And he ships product.
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