[95TA - The Beast]

Hey guys, I ended up buying a set of the Mishimoto catch cans for the ATS. Test fit them on my 2014 CTS and they fit nicely.

Now, before I go mounting them permanently and plumbing everything in, I am wondering if anyone considered an "auto-drain" setup for these cans?

The cans themselves have a NPT port on the bottom that is plugged. I know Mishimoto sells a setup with a hose nipple, hose, drain valve with barbed connections and drain hose that you can run under the car and just open them up when you change the oil to drain the cans.

Now, for most people that is fine, but honestly, why not put in an auto-drain back to the oil pan?

For that setup it would take a bung at the oil pan or into the crankcase. Does anyone know if the LTG has a plug in the block anywhere that a return bung could be installed into?

The other side would be a set of solenoids that are open with no power going to them and closed when they are powered. Hook them to the accessory or ignition power and the system is automatic. When you are running the car they would be closed and allow oil to accumulate in the catch can, but as soon as you shut the car off they would open and drain everything in the catch can back into the oil pan.

Side-Note: Before anyone gets upset about draining the catch can oil back into the crankcase, that is exactly where the oil is supposed to be, so it is just fine to do that. Quite frankly on race car setup as well as production external catch can setups form OEMs it is done exactly that way, they all drain back to the crankcase. Any water (actually condensation) that is in the oil will boil off during the regular running of the engine.

This way the catch can setup becomes zero-maintenance.

Looks-wise I wish it were a little more appealing, but it is what it is. I will be adding firesleeving to the hoses that run near the turbo, just to be safe, and for longevity.

[oemtech]

This is not going to be what you want to hear.
I tested the TRS Fab and the RX versions of the catch can system before I did the original testing of the Mishimoto system. All of them were a waste of money and time. I spent untold hours testing and $$$ only to find out that a $5 check valve in the fresh air intake line eliminated 90+% of the oil in the intake.

[Elite Engineering]

Well, first off is that Catch Can design will do little to benefit the engine due to it only trapping app. 15% of what enters it and allows the rest to be pulled through and still ingested.


Next is understanding what your PCV does to keep your engine alive. It constantly flushes the contaminant laden vapors from the crankcase so the engine does not wear out in 30-40k miles. What is caught in a good effective system is as follows:





70% is water and acids, 23% is raw fuel with a GDI engine, and only 7% is oil, and it is saturated with abrasive particulate matter. So if returned to the crankcase, your engine would not be long for this World. Most look to install a proper system to benefit the engine, not harm it.


We share these technical facts all the time and much more.


Below is how our top system impacts the oil over time as we improve the removal of the combustion byproducts substantially so the oil stays clean longer. This example is from a tech that challenged that claim about our E2-X systems designed for the GDI engines and he tested himself proving it. This is NOT from us. As we always share independent test data so our bias is not present:





Hope that helps you to understand this is not as simple as bolting on what is basically a beer can with fittings as most catchcans are not much more than that. And knowledge of what the PCV system does to keep your engine alive when several defeat the systems functions with breathers, etc.


Cheers!


More technical questions? Email us direct at: Tech@EliteEngineeringUSA.com

[wookwook]

a guy on here from the northeast used to catch can a lot of water in the winter. and probably more like what he said.

[95TA - The Beast]

Well, I definitely know what a catch can is, what it catches and its intended purpose.

Most of what they catch vapor-wise is a non-issue. You just don't want liquid going into your intake and coking the back of the intake valves. Routing ALL of that it catches back to the oil pan is a NON-ISSUE. The water vapor will boil off, the rest condenses and is recycled back into the oil.

Again, the purpose is to keep that stuff from coking the back of the intake valves. That only happens because of too much flow-through from the fresh air side to the PVC side in the "proper case" and in the "improper case" from the PVC side to the fresh air side (which is the big concern with forced induction systems as they create a massive suction on the fresh air side compared to a naturally aspirated system).

OEMTech, thanks for the input, I have read your posts in regards to the PVC/Fresh air systems and even though a check valve will reduce the amount of oil ingested from the fresh air inlet hose before the turbo, the big concern is a lack of ventilation under boost that occurs with a check valve as you stated. Ie, too much crankcase pressure is allowed to build (anything above atmospheric is bad) because of the checkvalve (ie, under boost the PCV system is inoperable because there is no vacuum present, thus vacuum from the fresh air line is needed to make up for the evacuation. Again, you cannot get away from the fact that the vapors/pressure have to vent somewhere, and that ultimately is back to the intake.

So, it is well known that catch cans do have their place in forced induction systems, jsut that most high-end systems that are low-maintenance end up routing back into the oil pan. Again, not a big deal since at operating temp the water will boil off quickly and honestly not much will accumulate per run cycle.

It is only preventative maintenance to want to prevent as much of that to go into the intake in a liquid form as possible. You will always have some vapor that will make it back to the intake and get burned, you just want to condense out as much liquid as possible. Ultimately you only want to burn off the bypass gases and allow the oil and stuff to go back to the oil pan, all while creating as much of a vacuum inside the crankcase as you can to prevent leakage and allow all the seals to do their job, which is keep oil in under vacuum. Those seals are not designed and intended to operate under pressure, so you can never allow pressure to buildup in a crankcase, thus a checkvalve is an improper solution.

[oemtech]

Originally Posted by 95TA - The Beast

snip
OEMTech, thanks for the input, I have read your posts in regards to the PVC/Fresh air systems and even though a check valve will reduce the amount of oil ingested from the fresh air inlet hose before the turbo, the big concern is a lack of ventilation under boost that occurs with a check valve as you stated. Ie, too much crankcase pressure is allowed to build (anything above atmospheric is bad) because of the check valve (ie, under boost the PCV system is inoperable because there is no vacuum present, thus vacuum from the fresh airline is needed to make up for the evacuation. Again, you cannot get away from the fact that the vapors/pressure has to vent somewhere, and that ultimately is back to the intake.
snip

Remember, there is a 3rd PCV valve on the valve cover that goes directly to the turbo. I tested that with a DIY filter. Not very scientific but it did show very little oil and I suspect it may have relieved the crankcase pressure under boost.

I ran the check valve setup at the Texas Mile and clicked off 144 mph.

[Evil-Bee-NH]

Originally Posted by wookwook

a guy on here from the northeast used to catch can a lot of water in the winter. and probably more like what he said.

Honest answer the catch cans are not worth it on these cars if your in the northern united states where cold winters happen. just get the upper induction cleaning done every 50k. You'll run into more problems then solutions with them on these cars if you intend to mod and tune and actually race more then twice a year. Do they work sure but they have alot of possible drawbacks that oemtech alluded to.