General Motors has just patented a passive two-stage oil separation assembly for crankcase ventilation, GM Authority has uncovered.
Assigned serial number 10,151,225 at the United States Patent and Trademark Office (USPTO), the GM patent was filed on October 26th, 2016 and granted on December 11th, 2018. Titled “integrated oil separator assembly for crankcase ventilation”, the patent lists Ko-Jen Wu and Jason C. Melecosky as its inventors.
The patent is comprised of two primary parts – an explanation of the claims made in regard to the oil separator assembly’s abilities, and a collection of six images that illustrate the actual parts as well as their locations on a hypothetical engine.
The Engineering
The proposed two-stage oil separation system is comprised of the first oil separator, which is mounted to the wall of the crankcase, and a second oil separator mounted to the first oil separator. This second separator provides further filtration.
The location of the first oil separator is dependent on the location of the first blow-by flow passage of the crankcase ventilation system as well as the first drain passage. The first oil separator’s internal baffling acts as a second blow-by flow and third drain passage, with the third drain passage flowing to the second drain passage of the crankcase ventilation system. A second oil separator is then mounted to the first oil separator, aligning with the third drain passage. The design of the second oil passage can then be altered to include a plurality of internal baffles or a filter.
In Plain English
If all that engineering jargon is too much, here’s an explanation in simpler terms: the crankcase ventilation system will vent air out through a first oil separator, and – through the use of check-valves – it may continue to a second oil separator. The direction of the air is dictated by blow-by flow passages, and the separated oil is returned through drain passages.
The air vented from the crankcase can go to one or more openings, including an air intake system which can include a turbocharger. The second oil separator can include a pressure regulator valve that can regulate the system’s pressure via check-valves.
The Benefits
An improved oil separation process can alleviate pre-ignition due to oil in the combustion chamber, which is a common symptom of small-displacement, turbo-charged engines.
In addition, the presence of oil in the combustion chamber can lead to particulates in the exhaust as a byproduct, which raises health concerns.
Where To From Here?
As emissions regulations continue to become ever more stringent, General Motors will be forced to deliver innovative ways to deliver cleaner and more efficient engines for its vehicles. In that regard, this two-stage oil separation system can certainly assist in doing so. The idea makes even more sense when one considers the fact that GM is beginning to use a highly-boosted, four-cylinder engine in full-size pickup truck applications – as it’s doing with the 2.7L I4 L3B engine in the 2019 Chevrolet Silverado 1500 and 2019 GMC Sierra 1500.
Considering the patent was originally filed over two years ago (in October of 2016), we believe that GM is looking to implement the proposed oil separation technology on a production engine at some point in the near future. In short, we expect to see a system like this one implemented in the near future as GM continues to improve and refine its technology while also meeting the demands of emissions regulations.
Current Uses
We have confirmed with Tom Read of GM Powertrain that the 3.6L LGX, 3.6L LGZ and 2.0L Turbo LSY engines are equipped with an integrated two-stage oil passive oil separation system. As such, it would seem that these engines are using the technology described in the patent.
To note, most GM engines use a passive system, but only the HFV6 and 2.0-liter LSY engines feature a two-stage system.
Patent Document
Check out the complete patent application in its nine-page glory right here (PDF file format).
Comments
GM has used this since 2016-17 on the latest LGZ and LGX 3.6 engines.
The separator system is in the valley area bolted to the block under the intake manifold.
Part number is 12668439.
Several companies were going to make catch cans till they found out they already had this system in place.
Yup exactly. The some LGZ guys have installed high end oil catch cans just to see, and after a good trial period confirmed that the in-crankcase baffles/channels are doing the trick, the aftermarket OCC has zero collected liquids
I have an OCC on all my engines, drain in once a month in the winter and on every, and between every, oil change in the summer.
I just sat back and watched as I saw what GM did and stated in the 3.6 upgrade but no one paid attention.
I expected the system to be I’m most all DI engines.
There is some type of baffling system in the valve covers of the ECOTEC3 L83 5.3L engines that separates the air/fumes from the oil. Best I can tell there are no PCV valves on the L83 engines, just a hose from each valve cover going to the air intake.
Yup ; knew this was coming ; coking of the intake valves on DI engines.
The L 83 in my Silverado has baffling in valve covers but they still say it needs a catch can.
The wife’s camaro 3.6 LFX I put a RX catch can on and every oil change I get 3 oz of oil in it.
I switched to valvolane modern engine which is suppose to have low vapors.
Can’t wait to see next oil change if the valve reduced the oil amount in catch can.
This is General Motors CEO Mary Barra demonstrating where the company is sweating out the details to increase performance and reliabiity.. hopefully Ms Barra can tell how this integrated oil separator would be used in GM’s upcoming all electric vehicle fleet.
Actually it is things like this under the skin that will be why these engines will be running years from now when the others will cost more to repair than they are worth.
FYI the all electric this is going to take time. The marketing of it is to boost the stock. Last look it appears to be working.
So this tech is NOT being used on the latest GM 4cyl. Turbo. ? Can’t remember the the engine code, LGY ?
So it sounds like a really complex, really expensive catch can.
Can someone explain why this is a good thing?
Read the Benefits above, as well as the comments referring to aftermarket catch cans requiring draining to capture oil that would have otherwise gone into the combustion chamber, and increased intake valve deposits on Direct Injection engines, increasing maintenance while decreasing efficiency.
I stopped using valvoline modern engine oil . Found no difference in the catch can results. 3 ounces after 5000 mi.
I am switching back to Mobil one synthetic after article claim it’s better and Mobil one 40 years and the first on synthetic oil .
I was trying to figure out the PCV System on my 2018 Cadillac XT5 3.6 L GDI engine.
Mounted on top of the intake manifold is a chamber that is connected to the inlet to the throttle body. This chamber also has hoses from both cam covers via a PCV hose assembly .
This chamber also has a hose called an overflow hose that I assume is piped back to the crankcase .
I also assume that any pressure in the cam covers will vent into this chamber . Does anyone know if there is any kind of pressure control valve in the chamber that would allow the control of venting into the port that connects to the throttle body .
did you ever get an answer on this? I have a 2017 lacrosse with the same weird system under the engine cover. I am looking to change the intake but am confused on rerouting this.
Is there an integrated oil separator being used on GM’s 2.7 L3B engine as suggested in this article?
I have a old can of empty Superior for sale if interested please email me back and I will send you pics
Can someone tell me if the water vapor from the crankcase goes back into the crankcase with the oil that is collected? Thank you