Oil Catch Cans Crankcase Pressure, Provent 200 vs Mishimoto vs Universal oil catch can

[@CensorshipGenesis]

Worth mention, never forget the "golden rule". Before doing ANY engine modification. Make sure the engine is performing to the best of it's own abilities. Meaning in this case. Make sure to PCV is working perfectly. And oil changes are up. All in all excelent video. Cheers

[@adrpals2324]

I've heard bad and good thing about catch cans, especially about the pressure in the engine. Your videos is great and a wealth of information.

[@hagridsbeardguy1399]

Logic is telling me that as the Mann paper filter gets saturated in oil completely, it'll probably increase the resistance. Great video thanks mate.

[@kevinoneill41]

Back in 1990 I saw a diesel engine generator with a 2qt paint can as a catch can filled a course fiber. The crankcase was vented straight to the center top of the can. The lid was perferated with what appeared to be knife stabing holes all over the top of the lid. The can was placed in a larger pan with an oil spill pad on the bottom. 😂😂 my guess is that this was better than venting straight to atmosphere. I had to open the can. What I found was amazing. It appeared to be working quite well. 😮

[@kevinm6283]

The best video and explanation I’ve ever seen. Very well done. And I’ve seen a lot of catch can videos. I run the brass micron filter and ordering the other can in the video right now. Thank you so much.

[@moremolecules]

Yeah, I was always concerned about crankcase pressure and if something will happen using them, hence the video. Basically for my own peace of mind.

[@stugillis]

You think the pressure wouldn’t increase so much in a petrol engine? Thanks

[@seanbrennan4447]

Great to find a channel that has the same car and age as mine :) thanks

[@moremolecules]

Hahaha, I know what you mean. Hope the videos are useful.

[@Thinkforyourselvz]

Thanks mate, as this is something I have been thinking about when I installed a catch can on my 6L LS. This clears it all up for me now.

[@KingZoneOne]

I have the Provent 200 on my petrol Audi A4, and I LOVE it! It's actually an oil/air separator (not a "catch can"), and it has both a pressure release valve, AND an active pressure regulating valve along with two different types of filter materials (nylon screen and sponge), a plastic coalescence screen, and room for an added wad of steel wool to increase coalescence. The type of filter element is really what matters. I'd never use a "catch can". They are overpriced, are nowhere near as efficient as an actual oil/air separator, and having TWO pressure regulators makes the comparison moot. .

[@stefanogallotta316]

Hi mate. Where did you buy the Provent 200? It is original ? I agree with you catch cans are useless. Thank you

[@owenhill-vf7ko]

As a 3rd generation mechanic and engine builder I don't use catch cans on my Ecoboost or DI engines. They aren't necessary. Use a good synthetic Oil, change every 5k miles,Tier 1 gasoline, replace pcv valve and coolant at 50k miles and zero problems!!

[@proobuio]

This is nicely done sir. I was wondering why mishimoto added those fancy bronze filters knowing that it would be add more restriction to the air flow. And im glad this answers it

[@BettaharMostafa]

Best Chanel for 1.6 hdi

[@jplunkett3647]

nice testing and explanation ..... due diligence / research is critical in ANY subject matter ,,, thank you ,,, i am now a subscriber based on this video

[@JRgarage1]

Fantastic video. Seriusly congratulation for make this test.

[@ahmedalhakimi7251]

Best video of catch can comparison

[@armandomolina8758]

Great information i run that universal can with steel wool. It catches 1oz in 1000miles

[@littlefishinggoat5409]

I just purchased a MH provent 200 for my vehicle. I'm glad to see I made the right choice.

[@fahdismalek7729]

thank you so much for exceptional information. i've remove the bronze filter.now car feel better

[@robh8131]

Really useful comparisons. I'm erring on a system for my UK 2 litre diesel that incorporates relief valves to allow 'through flow / bypass' if a filter becomes clogged. But put off by the silly prices of Genuine Mann 200 Pro Vent CC and the Flash Lube CC replacement filters. Many thanks for your informative test.

[@diylife1688]

very good test important to note that when the provent paper filter is dirty, it blocks considerably, i had this happen on my diesel. My oil was being forced out of my oil filler cap on rocker cover. So much!!!.the metal one not so mucj so if you've got all of these still i would recommend a second vid3o of them all dirty.

[@moremolecules]

Yes, I bet them all dirty will be quite a substantial increase in pressure.

[@offroaddst9747]

This is gold. Thank you very much sir

[@acaborneo5335]

I was used oct mishimito on my captiva diesel, its make engine seal cover leaks.thanks for make this video very very good

[@802Garage]

That's definitely why! Especially under boost, you crankcase pressures are going to be much too high. Lucky it was only your valve cover seal.

[@cmartin240]

Excellent research. I knew those damn 40 micron bronze filters would ramp up the back pressure. Great way to blow oil past the seal or worse, the seal itself is damaged.

[@enriquep4857]

Very nice video. Waiting for your "How to replace the trasmission of your Peugeot". I really need this video haha, my car is asking me urgently.

[@moremolecules]

Hahaha, luckily for me it is good for the moment.

[@steiljeds]

thank you. benchmark data is always best for breaking theories and myths

[@johnmcmullen456]

Thank you for all your efforts, found it very helpful.

[@802Garage]

Great test. Wow! That eBay catch can could create a lot of problems. That can cause the turbo oil return to be pressurized and back up. That will make the turbo smoke like crazy and can obviously make people think there are all kinds of issues. Not to mention other potential harm from high crankcase pressure. The ProVent 200 setup is impressive as demonstrated many times now. This was all done at idle? Under boost I imagine all of these numbers could change, but the eBay catch can would clearly become the most problematic. Good info to have!

[@moremolecules]

Yes, all was done under idle. I also tried to match the temperature of the engine, i.e. had a quick go around the block to bring the engine to operating temperature if I was fiddling for too long. Yes, the numbers would change under boost, but because there is more suction (turbo spool) the crankcase pressure is the highest at idle.

[@802Garage]

@@moremolecules I guess that would depend on how much blow by there is and perhaps it's different with diesel vs gas, but a lot of gas vehicles see the highest amount of PCV flow under high boost, but not necessarily pressure so I see what you mean. Yeah the turbo will be sucking the most as well, but if you were using a restrictive catch can like that, the flow could be far too much and the pressure would back up causing a massive PCV pressure spike. That's my concern. With a good flowing system yes pressure should be lower. :) Again awesome vid.

[@moremolecules]

@@802Garage Thank you very much indeed, much appreciated. Diesels are a bit different as compared to gas/petrol, they need their turbo, although naturally aspirated exist. Their max crankcase pressure is always at idle. I tested under boost and with any blip of the throttle, you get lowe crankcase pressure.

[@kevinoneill41]

I like the double catch can system. But that is just a play on emotions. After say 5000km how much oil. I will call it engine sewage that I do not want in my combustion chamber not ever. How much was collected in the cans. Did adding the second can help?

[@moremolecules]

Yeah, it was only an experiment, I did not run it with two oil catch cans for long. Nevertheless, how much oil is rather difficult to answer. I had quite a few videos about how much it collects. In all honesty it depends on how worn the engine is of course. Most surprising was that the oil catch can pretty much most of the time collects water. Mixed with oil it becomes a bit milky substance. Depends on the weather of course, here in the UK it is more often than not humid or raining, so I collected a lot of water, but say California or here in the summer it collects mainly oil. Not too much to be honest, but that depends on the engine.

[@deeproller]

Every time I change the Mann Hummel catch can filter with clean I notice the engine response is much better for a few weeks then drops off again, I am switching to stainless steel filter with scours added that would be much less restriction that an oil soaked Mann Hummel paper filter.

[@Hoster987]

very informative...as for In / Out, I also installed mine opposite of what's on the can and wasn't catching much. When I installed per instruction, it caught more oil / water - also just put fine mesh screens (2) in the baffle. I think either way is fine as you either catch the oil / water from PCV or catch before the air re-enters the intake. I also put a steel wool in there..not sure changing to copper scrubber makes any difference (Mishimoto's have "bronze" filter so.. :- )

[@cumshot247]

Why would you think think either way is fine, when you just said you installed the opposite of what's on the can and wasn't catching much.🤦‍♂

[@barniboy9336]

Thank you, thank you for a very nice, well documented and scientific approach ! I have also done my part of experiments and come to the same conclusion wrt. the sintered bronze filter. The pressure drop across those is rather high. In your example the filter looked kind of dry. But when this type of filter is wetted by oil droplets over (a short) time, the pressure drop will increase even more. These filters are simply too small in terms of filter area for an application like this, where just a few millibars matter. It is interesting to note, that only the Mann & Hummel filter takes advantage of the cyclone effect, by having a TANGENTIAL inlet. By this, the incoming fumes, with oil-droplets, will be whirling along the insides of the canister, splashing off most of the droplets (being heavier than fumes) at practically no pressure drop. An old trick from the process industry. There is another issue that I have not seen mentioned in the many Oil-Catch-Can videos: The intercooler ! Let me explain: A turbo-charged engine will have an intercooler. This is due to the fact that air is heated when compressed. When air is heated it expands and thus, less air/fuel will go into the engine and nothing is gained from the turbo. Unless you cool the air after the turbo. The intercooler is normally fitted under the radiator and is thus the lowest point in the air-intake system. Where do you think the oil-droplets and oil residues inside the air intake system is gonna end up ? Right ! Over time, must oil films deposited on the insides of tubes and hoses in the intake system is slowly, but steadily seeping down to the intercooler, filling it up. In fact, the intercooler is a perfect oil-catch can, being nice and cool, condensing oil-droplets in passing. Of course, the turbo outlet itself will provide a substantial pressure (thats what they do :-) and so some air is still gobbeling thru, but with limited, or no cooling action. My guess is that most intercoolers dont work. But then again: Its a good thing we never need those 250+ HP just by gurgling around town, so we havent noticed :-/

[@moremolecules]

Thank you very much indeed for the really detailed comment, more than appreciated. I would say it is somewhat scientific, as there are still a few variables unaccounted for, but still better than nothing I guess. Yes, the bronze filter has way too limited surface area. I think Mishimoto realised this as the huge Ford Cummins engine (6.5L) was throwing some errors and they produced a new oil catch can for this engine, much larger surface area and not 50 microns, but rather coarse mesh. Yes, the cyclone effect is pretty good actually. There was a scientific paper on that and it was the most efficient way without increasing/hampering the restriction/flow. I have thought about the intercooler, it is basically an oil catch can in its own right. I have already bought a second hand one to have some tests with it and will post a video someday. I am thinking of a semi-scientific way to test oil catch can efficiency and have some ideas, it is just time that is not enough. All the best.

[@802Garage]

Great insights, but one thing. Intercoolers absolutely work. The difference is massive. I highly recommend looking up the article "How intercooler design can changer the performance, efficiency and power of your engine" on Engine Basics as well as "Drop Intake Temperatures. Drop Track Times. Drop Jaws. The Ultimate Guide for Intercooler Selection!" by Mishimoto. The latter is much less data dense, but still demonstrates what a difference intercoolers make. Intercoolers are also a trade off between restriction, cooling, and efficiency.

[@craigdoherty2974]

Have used a few of the cheap ones and have been worried about the flow/ pressure. I extend the baffle or air / oil seperator with tube of alum, you can also use Plastic pipe. Keep it off the bottom about 3/4 of an inch and that is where I put the steel scubbing pad small amount . Wanted more time for the air/oil to drop separate by giving it a path and for it not for to just go in and out since they are beside each other. Will know next oil change if it sucks more oil than last time. Also like these for smaller motors as they produce less volumes of pressure. Bigger cubes more air. Got this on my Honda element and put the larger K1 on my Chevy G10 van . Seemed to smooth idle out somewhat to and I guess acts as a vac can storing it up for braking etc. You mention neg vac with turbo under load

[@moremolecules]

Hi craig, absolutely agree with the alum tube down. I should do that, it's been on my list, it would certainly help. I think there was also a modification, where this tube is with holes, so it does not restrict too much. Yeah, the air will find the shortest path, i.e. from one hole to the other.

[@craigdoherty2974]

@@moremolecules wondered about the holes but spoke with my flow bench guy and meh. Can cause turbulence i use a tube the size of the screen so no flow loss. Also as air hits the side drilled tube holes the oil which will be dripping down them to be sprayed doing just the opposite of what you want. Rather it go down tube then through the media/scrubber and find it's way out. Idea is oil drops in droplets/like fuel . Let the oil drop and air up . Not sure how to post a pic of mine on here maybe i will do a video. You can email me. If your still worried about bubbles try farting in the bath tub and tell me what happens ?

[@moremolecules]

@@craigdoherty2974 Yes, I'm worried about the pressure that needs to push the air through the oil/water that will have collected down there. If one blows through a straw in water, there is resistance. The holes in the sides are only for that purpose, the general flow will still go down. Yes, if oil/water accumulates down, the flow will go through the holes.

[@kevinoneill41]

I did something similar. A DIY "can" made out of 4" PVC a cleanout access with a end cap makes a 7"X4" can with a top screw on access lid, a 1" ID heater hose to the Can. Is fitted with a 90 % elbow or coupler at the upper end of the can facing down on the inside of the can with 1/4" holes perforating 1/2" tube or baffle 1" from the bottom of the can. The glued-on end cap is fitted with a 3/8" ball valve for drainage. The inside bottom of the can is raised 1.5" with an X pattern of 3/8" holes perforating PVC and then topped with a sink drain screen. From there to the top of the can and the 1" exit port is filled with copper pot scrub pads the last pad next to the 1" exit port is an SS pot scrubby pad. This is vented to the atmosphere with a one-way check valve and a valve cover CCV filter. As this can is mounted on the frame of my F350 4X4 6.4 diesel. The possibility of going through some water is low but still quite possible. I tested the exhaust out of the can with a little tissue paper. It appeared to be working great. We will see. I will check it at 500km then 1000km and last at 5000km for regular Oil and filters servicing and of course, undercarriage inspection.👍😊❤️🇨🇦

[@theseoldhands532]

the oil catch can at 12:00 it isnt backwards that isnt a baffle to stop oil sloshing and being drawn in its a baffle to help oil vaporize and stay in the can and not in the air it sis supposed to be on that side :)

[@moremolecules]

Did not quite get that, sorry.

[@etubrutus3501]

Once the filter media gets oil saturated I’m afraid that will restrict airflow causing case pressure to increase.

[@bobreese4807]

Yep, one of the reasons I am leaning to ADD w1 vs UPR.. ADD w1 is on sale for $109 for its V3

[@RockAndRollFirebird]

perfect work my friend! thank you for this valuable measurement... 👍

[@MrAcc45]

I suspected the bronze filter would increase pressure. imagine when it gets clogged up, the pressure would be even more I reckon.

[@moremolecules]

Hi Nizar, yes I was also suprised how much the pressure is with the bronze filter. It really depends on what pressure can the engine reasonable sustain. Overall there will be an increased pressure, but how much this will impact the engine is another question.

[@MrAcc45]

@@moremolecules Thx for the reply. I was worried abt this pressure. My engine has a lot of blowby and the pcv valve would get pretty oily and restrict flow. I keep hvg to clean it with brake clean very often. I have a replica mishimoto with the bronze filter, but this problem u highlighted was a big worry for me. thx for this video, it confirmed my fears. good thing the bronze filter is removable. I plan on removing the bronze filter and just keeping on the round baffle plate. currently im awaiting for some fittings via mail before install. in place of the removed bronze filter, i plan to screw in a barbed connector so that the blowby would have to travel down the can and up through the baffle and finally travel through the barb connector and out the can. hopefully it can capture the oils at the bottom without creating too much pressure. once i have setup I'll do a video and put a link. maybe provide updates occasionally.

[@moremolecules]

@@MrAcc45 That would be really good. Let me know if you do any videos, I'll post it on my community page.

[@phiksit]

Then throw in some cold winter weather and frozen water vapor will clog it up even more.

[@CrawldaBeast]

I feel like this could be very good information but done in a skewed way. Why would you leave the first catch can in series with the other two? The additional hose length plus the extra can all contribute to restriction. Not to mention, there ended up being a slight kink in the hose going to the last "universal" can. The other thing to consider with the filters is running a new filter (bronze or mesh) will flow far better than one with a thousand miles on it. So technically the second and third cans could be starting to see some filter restrictions caused by the first one starting to saturate.

[@jacovandenheever4318]

To test seperate will be more true test as all that beding and hose lenth will cause extra restrictions. Hope we can se can tests performing appart.

[@moremolecules]

It is a relative test at the end of the day. In addition, the bronze one is compared to another one with the same length hoses, so you get relative restriction compared to each other. The "fake" Mann-hummel does not add anything to the crankcase pressure, so leaving it there does not change the pressure.

[@gheorghinacov6008]

There is also difference in diameter of hose and connector. Mann-Hummel and your OEM setup got very large hose. Mishimoto and the unknown catch cans had very small diameters compared to the other setups. You can make the test again with the Mishimoto and unknown cans on cars with smaller vent hose diameter. That’s my guess

[@moremolecules]

Yes, I completely agree. It is rather difficult to detemine is the increased crankcase pressure comes from the catch can itself or the smaller hoses. I suspect it is from the hoses. Very good suggestion to testing the same with the smaller hoses for the Mishimoto and the other one. This should show if these increases come purely from the hoses. The problem is that the maximum hose intake is pretty small on the mishimoto. I think I have a smaller-sized port for the mishimoto so I can try it. Thank you!

[@gheorghinacov6008]

@@moremolecules And thank you for your videos! I wait for your next one

[@jasonhumphry5836]

@@moremolecules I'd like to see a hose size comparison as well as I have a dorman oil catch can on a 2012 chevy malibu running small hoses I've thought about changing to large hoses but I also don't want vacuum leaks and it's working perfectly awesome peace and much respect to you 👍 JASON awesome video 😀 👍 👏

[@moremolecules]

@@jasonhumphry5836 Smaller diameter hoses will add a little bit of pressure, but not that much. If you look at the video with the comparison of the cheap universal oil catch can had only little pressure above the mann hummel, despite the hoses being much smaller diameter. So, it will add a little bit of pressure, but not very substantial.

[@jasonhumphry5836]

@@moremolecules thanks for the added information

[@13adrian]

I have been looking at the mishimoto mmbcc-hf that has been mentioned as it hasn't got the brass filter it also has larger inlet and outlet I think 27mm

[@ericsson980]

Very informative. Great video sir. This is exactly what I'm looking for. I'm planning to install Oil Catch Can myself soon but wasn't sure if it's good because some video said not to install it because it will increase the crankcase pressure. Now I know it's the internal design of the Oil Catch Can that effect the crankcase pressure. Got the 'cheap' Oil Catch Can exactly like in your video in our local store. Will get those soon. Thanks again for this video.

[@ericsson980]

Also my car is Mitsubishi triton 2.4 mivec. Has over 100k km on it. Do you think it's too late for installing Oil Catch Can? Thanks.

[@moremolecules]

@@ericsson980 Never too late really. 100k is not that much anyway, so perfect time to put one.

[@ericsson980]

@@moremoleculesthank you sir

[@ozstriker4075]

Excellent video with great testing methods. So I've got the numbers right, the actual pressure with the mishomoto + bronze filter was 4.62mbar? (6.20 - 1.58 as it was connected with the man Hummel)

[@moremolecules]

Almost correct. The Mann Hummel 1.58 was 0.01 or so different from the natural crankcase pressure of the engine. So, leaving it there does not add more crankcase pressure, thus no need to do 6.20-1.58, it is 6.20. Hope that makes sense.

[@Refertech101]

Yes you can have some thing that filters good with small delta P, but like any thing, you pay for it, and size is larger, the Parker CCV systems are very efficient

[@deanword6500]

Very well instrumented testing and thanks for the suggestion on electronics. However, only looking at idle conditions is not a good analysis. The engine spends most of its time at engine speeds far above idle and under varying crankcase pressure/vacuum levels.

[@moremolecules]

I completely agree. The test I wanted to do is: "is there an increase in crankcase pressure with different oil catch cans". The highest crankcase pressure will be under idle, so that is why I did it under idle. Of course, there will be different vacuum/pressure levels under load, but very difficult to test under normal road conditions. I would not be able to replicate the same journey. If there is a dyno or rolling road, then it can be done, but I have not got access to these. It can be done with driving on normal roads, but then again one needs to repeat it several times, then averages, distributions, standard errors, etc., and it will become a statistical test. Most people will switch off and not follow in order for the test to be accurate and representative.

[@xabizar]

Great work! Is it possible that the actual mishimoto catch can's bronze filter is less restrictive than the cheap copy's filter?

[@moremolecules]

It is possible, but unlikely. I linked a video (in the description of the video)) of a comparison of the original mishimoto and the "fake" one and they are identical. I suspect it might be just the same factory producing them, but does not label them mishimoto

[@GCS88]

I've read in a forum before that its pretty restrictive, Mishimoto has then redesigned and replaced the bronze filter with some kind of big pore sponge type filter that covers the whole ceiling area of the can.

[@NZbluesky]

Thank you for displaying your benchmark research. I have just fitted a Provent 200 to a diesel JK wrangler 2.8 Turbo intercooler model 2008 mileage done 200k. The kit from Germany came with quite a few right angled 90 degree connectors. AND THAT is my question. These connections are all internal to the main hoses? So would that push the pressure up? Like a water blaster effect? When I put my figure or white paper over the output of the Provent onto those small right angled connectors there seems to be no pressure at all? What do you think? I thought maybe I would change the position so it just uses the larger [and shorter] rubber pipes as suppled? Any thoughts? Interestingly to myself.... My jeep seems to have picked up power since fitting this Provent?

[@moremolecules]

Yeah, I always thought that many right angles will lead to a little bit of pressure going up, not proably a lot less than one thinks. Restrictions (narrowing of pipes) are are probably the biggest pressure increase, although also not by much. As far as I have learnt, main pressure increase is likely to come where the air/gasses are stopped or are hitting something, like a mesh or even finer filters. It is just a guestimate of course.

[@marioroque3768]

Thanks very much for sharing this! Very useful

[@armandomolina8758]

I was also worried about the pressure on that bronze screen choosing im ordering the plastic can im sold

[@jasonyoung5960]

I have one of thoes ones with the brass filter. I drilled 4 small holes in the filter and then filled the can with steel wool. I thought it looked restricted. Cheers

[@bobreese4807]

Good idea

[@boxpimp]

I’d be interested in seeing what vent to atmosphere pressures look like. I can’t find any info online. It might not apply to your vehicle but plenty of people run breather cans

[@moremolecules]

Hi Jason, I do not quite remember if I did this test, but might do a quick test and compare the crankcase pressure with venting to the atmosphere.

[@mrmotorvator5151]

I run mine to atmosphere using 19mm id hose..seems to work well and can only benefit engine internals..no brainer

[@AndoniFV]

@@moremoleculesllegaste a probar que presión tenías a la atmósfera? Un saludo?

[@moremolecules]

@@AndoniFV Unfortunately I never did venting to the atmosphere test. I did not have at the time a filter that vented to the atmosphere, otherwise I would have tested it.

[@bogdanelgiu7822]

Hi man , thanks a lot for making and sharing the video, it has really good information and data comparison , has helped me understand how such a system works. I have installed a no name catch can with brass baffle ,drove about 6000 km and concluded that the engine has burned/leaked about 2-2.5 litres of oil . Now , I took the system out to see if the engine itself is defective or if my catch can system was somehow fault. I have the car only 5 months so I don't know yet if the engine burns oil or not, no blue smoke whatsoever and no puddel under the car.I must mention that out of the 6000 km , I drove about 4000 only on the motorway and up to almost 3000 rpm. Now the questions taking in consideration all the above, if it was the catch can's fault and was too much of a pressure in the engine, have I done damage to all the seals and o-rings inside ? Do you think it will still "burn" the same amount of oil without the catch can system? I would be glad to hear your opinion on this, thank you and keep up the good work !

[@moremolecules]

Hi bogdan, I completely understand your concern/question, but really difficult to answer conclusively. The bronze oil catch can does add to the crankcase pressure, but it should not be enough to cause oil leakage from the seals. It could be, but difficult to say with certainty. Depends what your engine is and what the current crankcase pressure is. If the oil catch can was enough to cause seals leaking, it would have happened anyway. The other thing is that depends on the hoses and your CCV/PCV valve. If the hoses collapse under pressure/vacuum, then that could have contributed rather than the oil catch can. It could be that the CCV or PCV (depends on what is in your engine) could be blocked or not working, that would certainly lead to oil seals leaking. You may need to investigate where oil is leaking from, as it may well be say be the sump plug.

[@hemakalpoo5686]

@@moremolecules Good day sir, I don’t know much on these things and oil catch cans. I have a Holden Colorado with a 2.8 Diesel engine and recently bought a mishimoto oil catch can with the Bronze filter and baffle. Would it be ok for that engine or should I remove the bronze filter?

[@moremolecules]

@@hemakalpoo5686 It really depends on the condition of the car. If it is in a good condition, it should be alright. I mean how much of a breather is the car, if it is not too heavy breather then the increase in the crankcase pressure will probably be OK with the bronze filter inside.

[@carlosbah4623]

Gran trabajo.¡Gracias por compartir!

[@CONFUCIUS-f2x]

How about making more tiny holes on the disk baffle for more air flow and removing the bronze filter and adding the scrub pad?

[@moremolecules]

Yes, that would work, but then again it will not be too different than the cheap one with the larger holes and the scrub pads. I guess that the bronze filter with a few larger holes will reduce the increase in the crankcase pressure.

[@CONFUCIUS-f2x]

That sounds like a good idea. Weekend project. Thanks Molecule.

[@jacovandenheever4318]

Think a better test to test fist can, is to let it run first for a while to get soaked with oil. As it soaks up all the oil first than drain to bottom. Than restriction will be more. Want to agree with Joshua Gracias with turbo engines its sucking air through more, that the cans a better option

[@moremolecules]

I agree that getting an oil catch can soaked with oil will increase the crankcase pressure, as they become more restrictive. It does not matter if there is suction from the catch can or not, there will always be suction there, at the end of the day it is connected to the turbo. It just matters how much restrictive are the passages.

[@ViruZHUN]

Recently built a new 2.0hdi engine with the mishimoto knockoff with bronze filter. The oil was coming out of the rtv sealed places, getting rid of that shit.

[@north4961]

Congrats on a job well done! Excellent video explanation! Exactly the info I was looking for my 2014 3.0 liter Ecodiesel. Im going with Provent with stainless like yours, but before I put on I am going to run HoTShot Stiction oil treatment. If I do before, Hot Shot Stication will not reach the turbo through the vapours , which it relies on. LOL - I might end up putting 2 Y's so when I want to run oil treatments I just turn the 2 valves? your thoughts?

[@moremolecules]

Thank you for the good words. Not familiar with the HoTShot oil tratment, but in any respect any oil catch can is not 100% efficient. Various percentages thrown around on the web, so in any case something will pass through. I have to pass annual inspection every year and my oil catch can is deemed an emissions modification, despite that it helps rather than produce more emissions. I simply remove my oil catch can system and put in the stock. You could use similar way to run your treatment. I know it is a faff.

[@davidwarren4569]

I don’t think those metal catch cans are meant for diesel engines, just petrol engines. But a nice analysis. Well done

[@moremolecules]

Yes, could well be, although in the description of these they always put diesels as well. Overall there is a bit more crankcase pressure in the diesels as compared to petrols.

[@FixItWithJon]

Love your videos. Did you buy a hose & mounting kit for your Provent 200 or did you have to buy separately / make up a kit?

[@moremolecules]

I made my own kit with the hoses and the mounting stuff. Unfortunately, for my car there were not any mounting kits and space was quite tight.

[@nespokesman]

Excellent information. Those bronze filters are crap, the makers aren't even standing behind them. 4 times the pressure, what the hell....

[@moremolecules]

I was also surprised that the pressure was that high with the bronze filter. Although, it will probably filter quite well due to the really fine holes inside, allegedly 50 microns.

[@nespokesman]

@@moremolecules I noticed an orange cast on my spark plugs months after installing the bronze filter type. It appears that the pressure in the engine was forcing oil through the valve seals and that orange cast was oil additives. The bronze filter becomes clogged.

[@moremolecules]

@@nespokesman Thank you for sharing this. Because of this increase in pressure I decided not to use the catch can with the bronze filter. If they invent the same catch can, but with some sort of a by-pass relief valve, like the Mann Hummel one, I would definitely consider it.

[@gregnixon1296]

What kind of hose is necessary for catch can back to intake? The 3/4" heater hose that I used collapses. Heat from the engine makes the hose pliable, and the intake's vacuum pressure causes it to collapse.

[@moremolecules]

Hi Greg, yes the usual hoses that are supplied with catch cans are too weak. I use fuel hose 25mm. It is a bit on the thick side, but it will not collapse, it is too rigid. The other option is to get reinforced silicone hose, but it has to be fuel safe, otherwise it will disintegrate eventually.

[@CarminesRCTipsandTricks]

Teflon lined Fuel Hose is actually the best. More expensive, a little harder to work with - but VERY stable and durable. It's impervious to Chemicals, which is why it's popular to use with E-85 Ethanol Fuel Systems.

[@moremolecules]

@@CarminesRCTipsandTricks Great advice and many thanks indeed. I will have to investigate this to see if I can purchase and replace my own hoses.

[@franabad]

Awesome video, wished I found it a couple of weeks earliers! Just installed a Mishimoto on a diesel Mercedes ML270, definitely not comfortable with those values. Nevertheless, the main problem I've been having is that I'm getting oil from the "out" port. Tried it the other way around, the "in" port throught the bronze mesh, and was getting better results, any ideas why? Anyway after watching your video, i think i will remove it completely

[@moremolecules]

Well, not too sure why it is gathering oil on the out port. THe oil catch cans are not 100% efficient for separating the oil, so you will always get some on th eout port.

[@allahasan6631]

I just bought a mashimotto repleca oil cath can same as yours with the bronze mesh . I have a civic with r18 na engine 1.8 lit and i want to put this oil cath can in but after what i saw maybe i wont i thinking about take off this bronze filter and put the stanless steal mesh that yo put bittwen the top cap and the steel plate (that with hules in it ) it will be alot of filtering mass and a better air flow can you check that out 😉

[@moremolecules]

Hi Far, yes, I was really surprised as well that it increased crankcase pressure quite a bit, I would say significantly more. Nevertheless, it's only 6mbars, so not that much. Then again, depends on what the engine can sustain. I suspect that this bronze filter will really filter oil rather well, apart from the crankcase pressure.

[@allahasan6631]

@@moremolecules i think its a good design to but if that pressure can blow gasget like between the engine and gear one its gone be lot of mess work and money its not like leaking from valve cover gasket

[@moremolecules]

@@allahasan6631 Yes, but that is the problem with oil catch cans, it is somewhat a trade-off between efficiency (fine filters) and blowing gaskets. So far I have not seen anyone investigating how much pressure is needed for a gasket to be blown and start leaking. If an engine is a heavy breather, then an oil catch can will add to that, so making matters slightly worse. The leak most likely will be between the block and the rocker cover, rather than anywhere else, but that is only a guess.

[@bengleckl1877]

So what is the safest way to hook up a catch can system?? Mine is a gasoline non turbo. Do I need two catch cans or is one good enough??? Just one catch can with no bronze filter would be best??? I assume id want it to be the same pressure it was before I installed anything?

[@moremolecules]

Hi Ben, apologies, I probably made it to look more complicated than it is. Only one catch can is enough, preferably the non-bronze one. If you engine is not too worn (not much blow-by) then even the bronze one will be quite good. If you have an older engine, then I would not recommend the bronze one. Yes, you want the pressure to stay as low as possible. I only used the two, as it was easier and I had them hooked up already.

[@kumara5492]

Well detailed video. I followed your video and installed OCC successfully. I ran my Toyota Prius hybrid on maintenance mode for almost an hour ( to check if it's still overheating intermittently due to weak water pump that I replaced with new water pump and that's been fixed ) but I noticed the hose that I connected from outlet of Oil catch can ( universal OCC) that goes into the intake manifold was completely flat due to high pressure. Do you think OCC might not be functioning as it supposed to or should I replace the hose with the heavy duty hose ( thicker one) , like the one I got that connects from PCV valve to inlet of OCC. Do you think I need to get a fuel line hose which is thicker than the one I installed ( maybe I got radiator hose ) .I subscribed. Thank you for you reply

[@moremolecules]

Yes, replace the hoses with heavy duty ones that would not collapse under pressure/vacuum. I would get something that is fuel safe hose, but such that it would not collapse under pressure.

[@araboharabedian]

Interesting video and it got me thinking about my car and how I have the catch can Installed. In a gasoline naturally aspirated inline six cylinder engine would there be much concern for increased crankcase pressure if I decided to use the mishimoto type bronze filter cans? I’m only asking the question since I can really benefit from the decrease of blow by into my intake manifold but not at the cost of raising crank case pressure and blowing out all my seals and causing leaks I do not wish to have 🤷🏼‍♂️

[@moremolecules]

Good question. I would always thread on the cautious side of things and get a bigger (if there is space to fit) oil catch can, for example the Provent200 or bigger.

[@mohmadJO]

Hello my friend I installed a cheap type oil catch can and it comes with a small filter on top Note that I bought the car three months ago Diesel engine 2500 A month after installation I found a little oil around the manfold casket and inside the intercooler The engine is good, there is no black or white smoke, and there is no oil loss after traveling 3000 km I really don't know if the reason is old or the cause is the oil catch can do it Another question Should the installation be done away from the engine, away from heat? Does it need to be installed a little higher than the engine level? Finally, sorry for my many questions and sorry for my English

[@moremolecules]

Not too sure what the problem is, but ideally you need to place the oil catch can as far away as possible from the heat. At the end of the day the oil catch can is a condensing thing and the bigger temperature differential really helps with condensing oil/water, etc. So, if you can cool the oil catch can really well, say with ice or cold water then the efficacy will be really good. Unfortunately, this is not practical in engines. I would not install an oil catch can higher from the crankcase breather, as the condensing fluid will come back and plug the hole. Ideally you need to put it lower than the crankcase breather so any fuild/oil to go into the oil catch can.

[@ragheedhamdan]

Great video. i have been looking to install an Oil catch can on my gasoline engine for a while now. After watching your video, i got concerned about the positive crankcase pressure problem. Do you think installing an OCC with brass filter a bad idea?.

[@bobreese4807]

Yep, one of the reasons I am leaning to ADD w1 or UPR.. ADD w1 is on sale for $109 for its V3. There is a YT video where a guy uses a cheap $20 OCC and removes the brass filter. I would always advise that.

[@hulong0205]

I would like to know if oil catch can will create damage to gas engines. 3.8L V6. Do yo have a test for gas engines? Thank you.

[@moremolecules]

Hi there, I really like your question, but very difficult to answer without having your particular engine at hand to do tests. No, I do not have a test with a gas/petrol engine. Nevertheless, the crankcase pressure increase will be the same. The issue is that this is relative. So, if you add a glass of water to another glass of water that is a lot, but if you add that same glass of water to a lake, not that much of an increase. What I want to say is that it depends on how much pressure your 3.8L V6 can sustain or what is normal for that engine. My tiny 1.6L (4 cyls) can only sustain max ~40-50mbars without oil leaking from the seals. Now, pressure in the gas/petrol engine is normally a lot lower than a diesel, so difficult to say without experimentation, unless you know your normal crankcase pressure for you engine.

[@hulong0205]

@@moremolecules thank you for your answer. This answered a lot of my questions. Like pressure difference of diesel vs gas. Appreciate your time and help.

[@moremolecules]

@@hulong0205 No worries, unfortunately I cannot provide more info on that, but that is the general kind of way these things work. Very difficult to get this data (normal crankcase pressure) from the manufacturer, unless one bought the car from new and measured at the very beginning of ownership.

[@thegreatfixer]

thank you excellent demo

[@moremolecules]

Thank you for the comment and encouragement

[@johnnystoka6625]

What steel scourer material did you insert in the steel mesh Provent filter ?

[@moremolecules]

I do not remember the actual brand, but some generic stainless steel household scourers. They have to be stainless steel, but any that are that should do.

[@johnnystoka6625]

@@moremolecules Thanks . Do you also know if the Provent 200 mark IV has an aftermarket stainless steel filter that will fit as I have seen there might be fitting issues with certain models .

[@glenncivale6824]

Excellent Information, TY.

[@DominicLeung87]

Sorry if I'm being stupid but your pressure numbers are "delta to atmosphere" right? 6mbar is 4 times 1.5mbar sure... but we're taking about less than 0.1psi, surely that can't really make a difference for the sesls in the engine...

[@moremolecules]

Hi Dominic, yes it does not need much pressure to do damage to the seals. I know it is tiny pressure, but the maximum for these engines and a few others is ~35mbars. The original Mann-Hummel Provent 200 has a pressure relief valve on top that opens at 50mbars, so this is really the maximum that they think is quite high.

[@DominicLeung87]

@@moremolecules that's quite interesting I haven't really heard of this being an issue before but it does make sense upon thinking about it further Thanks for the hard work putting all this to the test!! If you don't mind discussing a bit further though, do you think the situation /issue you described is the same for turbo- gasoline engines? I just ordered this unit from mishimoto(www.mishimoto.com/mishimoto-baffled-oil-catch-can.html) that has a removable bronze filter which seems to have bigger surface area (which should reduce pressure drop), what do you think of the design? Should I run the catch can with the filter removed? At the end of the day the catch can add a device is facing an engineering challenge with two conflicting conditions. Like any filter it needs to flow well, and to filter well. Certainly there can be "bad" designs which do both poorly or performs very well in one area at great expense to the other. What design elements do you think are indicative of a system which can do both things well? To me it would be : Size - a large can would allow the crankcase gasses to slow down (atleast a bit) making it easier for the oil droplets to come out of suspension Flow characteristics - designing the can in such a way that the crankcase air "fully utilizes" the space in the can so it can achieve the effect described above Filtration - something to "actively" encourage separation between air and oil vapor, you're could be a fibrous element, or bronze "sponge" or centrifugal vortex (like Dyson vacuum). Obviously it is case dependent but which area should we prioritize, the filtration or impediment to flow?

[@moremolecules]

@@DominicLeung87 Thank you very much indeed for the really thorough and good comment. I absolutely agree that it is a trade-off between efficiency and flow (increase in pressure). There os very little amount of actual academic research on this subject. I think I found one single paper that talks about the components in an oil catch can. The paper mainly looked into how the air needs to swirl around in order to maximise the amount of time the droplets/air are in contact with the oil catch can surface in order for them to coalesce. The research showed that circular motion of the air is the most efficient, that is the same design as the Mann-Hummel. Unfortunately, they did not go further into this. The problem is that how much is too much pressure. There are too many factors to account for here. How old/worn is the engine will determine the amount of breathing the engine does, the more worn it is the heavier the breathing and the same amount of restriction (oil catch can mesh) will give you different crankcase pressure. For some engines this will result in leakage from the seal, others would not. As far as I am aware almost all catch cans are the same design with variations here and there. Nevertheless, mishimoto noticed that in diesel engines, albeit the really big 6.7L ford cummins, their oil catch cans creates too much crankcase pressure. So, they designed a new more permissive oil catch can. When I say permissive, I mean bigger surface area, as you mentioned in your comment. www.mishimoto.co.uk/ford-67-powerstroke-catch-can-install-2017.html If that oil catch can was available for a reasonable price, I would definitely buy it, IMHO seems like a very good compromise of everything. The overall problem is how much crankcase pressure is OK for the engine. Very difficult to answer and very little information anywhere. I managed to find only one single source for a mini petrol engine and the maximum there was ~20-30mbar, which is not that much actually. I could go on about this forever, but my reply would turn into a blog post :-). Hope that is somewhat helpful.

[@DominicLeung87]

@@moremolecules awesome man Yea there really isn’t much research on the topic other than those done by the amateur grease monkey I’ve been scouring the internet the past 24h after I saw your video My catch can just arrived in the mail today and I’ll probably just install it. I’ve got a bmw 2.0 turbo which shares the same pcv hose diameter as bmw’s 3.0l turbos used in the M2 M3 and M4. Given blow by is largely a function of engine airflow (i.e power), I figure that even if the Mishimoto catch can I bought comes with some restriction, atleast I have a lot of headroom given the stock tubing is massively overbuilt. Super finger in the air approach 😀

[@moremolecules]

@@DominicLeung87 Good luck with the catch can. It should be OK. I have an idea of how to test different oil catch cans, but I will see if I can do it. Most of the grease monkeys just say, "ohh, this oil catch can is the best", etc. There is no comparison whatsoever, as long as there is something collected in the oil catch can. The problem of course is to emulate the size of the droplets, as the function of the oil catch can will depend on the size of the droplets. No easy way for me to test their size, apart from a sophisticated scientific equipment.

[@tracylewisperformance1328]

Why not use an actual air/oil separating crankcase evacuation system that provides full time vacuum on the crankcase? Pressure is never good, and all shown is only using intake manifold for vacuum source.

[@moremolecules]

Hmm, many thanks indeed for the comment, but I am a bit confused. What would that system be? Where would one take the full time vacuum? I suspect of course I can use the car's vacuum, but I simply used the current setup, only extending the path with an oil catch can.

[@scoupemaster]

thanks for the info veru good explanation and test!!!!!

[@MatkoJun]

@moremolecules I'm wondering - could increased pressure for mishimoto/universal catch cans be due to much smaller in/out ports? ProVent has 24mm internal diameter input/output ports whereas mishimoto and other cheap copies are usually around 10-12mm and the biggest I saw were 19mm outer (16mm inner diameter). It would be interesting to see what would be the pressure if one would make ports for mishimoto/universal bigger - say 22mm (which is original hdi hose connector inner diameter)

[@moremolecules]

Most of the increase in pressure does not come from the hoses or the smaller in/ou. I did try the Mishimoto/KKmoon without the bronze filter to see how much this adds. It was relatively substantual increase in pressure, so not just the hoses. But they all add to the increase in pressure. Basically, the bronze filter is the biggest contributer to the pressure increase. At the end of the day it is a balance between complete efficiency and permissive. If you have complete efficiency or close to that, it is to create resistance as the gasses need to pass through something where they have to coalesce, hence the increase in pressure as too big holes and you have little efficiency. Gas molecules, even laden with oil/water are still pretty small molecules.

[@keepitathousand420]

Great test! i was wondering if you can do the reading tests again but after 10-15 minute to be more accurate. Again thanks for the helpful video

[@moremolecules]

I wanted the same condition for all catch cans, so the engine was always in operating temperature. I can wait for the engine to be cold on all catch cans, but I cannot control how cold the engine will be, but I can always keep the engine in operating temperature, so more consistent test across the catch cans. Is that what you meant for the 10-15min wait?

[@keepitathousand420]

@@moremolecules yeah of course it does give more accuracy doing the tests while engine is in operating temperature although you could try test while its cold it won’t hurt to see those numbers before warm up, but what i meant is could you repeat the test after idiling or driving for 10-15 min?

[@moremolecules]

@@keepitathousand420 Yes, the cold ones will be quite big, depends on how cold of course it is outside. Before doing the video I did quite a few runs on this to see what works and is the most representative. Generally, once the engine is relatively hot, the crankcase pressure does not change too much. Say if I drive for a bit and measure then will be almost exactly the same as if I had stopped for 10min to change the catch cans. I can probably do it anyway and see what comes out.

[@moremolecules]

@@keepitathousand420 I probably could, it would not hurt, but the difference is very little between these.

[@Pacobravo16]

The question is a open to atmosphere can reduce pressure???

[@moremolecules]

Yeah, I have not done that, but I doubt it, unless it is not a turbo version. With the turbo version, the pressure gets reduced by pulling the air. So, pretty much when the turbo is spinning the pressure is reduced. With the atmospheric one, there is nothing to pull the pressure out of the crankcase. That is my opinion and can stand corrected of course.

[@ΒΑΣΙΛΗΣΚΥΡΕΖΗΣ]

On the cheap catch can the intake and outtake inner diameter of threads how is it?? At man hummel is about 25-26mm and at i believe is around 10mm so that's probably why is a little more pressure.

[@moremolecules]

Yes, could well be. As far as I remember the diameter of these were ~8-10mm, so twice smaller and the size of the can is smaller.

[@smartbidshop1]

Did you seal the valves on the prevent catch can

[@2525miche]

If the Universal Aluminium Engine Oil Catch Can ahave a breather on top, is it still good?

[@moremolecules]

Yeah, it is still good. You can either block the breather or put a filter on it.

[@Mark_182]

Hi!! excellent video! cool!!! So would the kkmoon's copper filter be a good system for gasoline engines? Or would you recommend the Provent for a gasoline engine?

[@moremolecules]

If you can afford it I would still use the Provent, although the kkmoon is also alright. The only negative of the provent is that you need to replace the filter every so often, probably something like 20k miles.

[@Mark_182]

@@moremolecules ok!! Actually, the issue of changing the filter doesn't bother me, if it helps the engine, it's fine for me, thanks for the help!!! 🤘

[@moremolecules]

@@Mark_182 I am always penny watching, so that is why I mentioned it. If you have not probelm with cnahging every so often it is a good system.

[@Mark_182]

@@moremolecules excellent thank you very much!!! 😃

[@smailberrani2914]

Malheureusement je ne comprends pas très bien l'anglais, mais vraiment ça me semble exactement c'est qu'il faut pour ma 308 1.6 hdi, je ne sait s'il existe un version française, ce serait idéale et intéressant pour beaucoup de monde.

[@moremolecules]

Hi smail, merci beaucoup. I do not speak French, but there is auto translate in youtube. That in theory should work ok.

[@rachidsinno2487]

So this test is for dieael engines. Any test on petrol engines, will the bronze filter increase the crankcase pressure as well...

[@moremolecules]

Yes, this is for a diesel engine, but it will be the same with a petrol engine wih respect to the increase in crankcase pressure

[@kev48]

good morning friends, I am at the stage of diagnosing this engine and spitting oil from the oil pneumothorax onto the entire intake system. I started by replacing the valve covers, like probably each of you. there was peace for a moment. Next came the turbocharger. Of course, while doing this, I changed the oil and cleaned the entire intake system through the intercooler throttles, ending with the intake manifold. This brought only temporary relief until the entire system was filled with oil from the pneumothorax again. I started the next work on this engine by dismantling everything so far, this time a step further on the head. after replacing valve seals, cleaning new camshafts, new valve levers, I assembled this engine, although I know that I will start it again in a moment. I deliberately did not remove the pistons to confirm that the problem was not in the head. For now, it's just a guess, but I think that blow-by in the crankcase that blows oil through the exhaust valve is caused by worn piston rings/cylinders. so if you have a symptom like blowing oil cap, you have a long way to go home. Regards

[@Lebanese_housos1983]

It would be good to compare a cheap catch can with a breather on top for pressure value

[@moremolecules]

Yes, that would probably be interesting, although I am not entirely sure about it. Say if you are running the car in gear down a hill, the pressure in the crankcase will be negative, but if the breather on top will negate this.

[@Lebanese_housos1983]

more molecules found out that breather are illegal in Australia 🇦🇺 not allow to let fume oil out into atmosphere

[@moremolecules]

@@Lebanese_housos1983 Due to emissions that might be illegal in most conutries. The oil catch can system is a close one, so nothing is vented in the atmosphere. Most likely reduces the emissions, as it reduces the amount of oil burned.

[@kayakwesty]

Thank you for this video. I will be buying a knock off Provent 200

[@JohnNorris411]

So what is the difference when using these on a gas engine?

[@moremolecules]

Less oil vapor going through the engine, so it keeps the air intake clean, so the overall volume can be kept quite large.

[@francescocarulli2401]

Ciao complimenti per il video. Hai mai provato il decanter con l'altro filtro sopra?

[@moremolecules]

I tried translating the comment, but was not too sure what it exactly meant about the decanter with filter on top. Sorry.

[@marchiegalorio5751]

Hi, do you have tutorial on how you set up all that pipes? i want that idea to avoild damage of turbo charger. Because in normal pipes even there is no leak i saw black oil in the turbo.

[@moremolecules]

Not too sure what tutorial, but I have a tutorial how I installed the oil catch can in my 1.6HDi, a whole plalist here with 2 videos how to do it: kzbin.info/aero/PLx5YM-qLHn7wtOnyXn0MohIjAVivvG_nw And how to replace the turbo in the 1.6HDi: kzbin.info/aero/PLx5YM-qLHn7ycuP79oti5D19COwGLmIhe

[@marchiegalorio5751]

@@moremolecules thank you

[@ptownhoopsquad]

Hey, great channel, loads of very good info. Just wondering if you have replaced the plastic inlet manifold? I just got a 1.6 hdi 145k miles. The inlet is really blocket up with carbon and goop. I dont think i will be able to clean it out of the plastic inlet. So i want to buy a new one. I am looking on ebay and all are aftermarket, just wondering if they are any good quality

[@moremolecules]

Thanks for the encouragement. Which plastic inlet manifold is that? Is it the PCV valve one?

[@exoc1]

Hello. Since the normal air pressure at sea level is roughly 1000 mbar I fail too see why i sould worry about 6mbar over pressure that's not even 1%. I can't imagine that is going to pop any seals or so.

[@moremolecules]

A normal engine will have a limit of the internal pressure for the seals. I cannot quite find you the reference at the moment, but the limit is ~30-35mbars above atmospheric. So, it is not 6mbar out of 1,000, but 6 out of the 30-35mbars, that is significant. Different engines will have different limits, I think I am quoting the mini petrol engine, cannot quite remember which version.

[@exoc1]

@@moremolecules oh really, as little as 30-35? I assumed the seals would withstand more, thx for the info. I just ordered one of those catch cans with that bronze filter for my Sea-Doo. Maybe i should consider changing the sintered filter for some steel wool.

[@moremolecules]

@@exoc1 I can probably find the reference for the mini engine, I think it was a naturally asirated 1.6 petrol. It is the only engine pressure I have ever found. As far as I remember it was 50mbars max and normal pressure 30-35mbars. That is above atmospheric of course.

[@Neema1135514]

Hi nice video, Do you think that leaving the return pipe to the turbo disconnected will change anything apart from emissions ? or there is another reason for the return pipe to go back to the turbo !

[@moremolecules]

Hi Jaber, it has dual purpose. One is the emissions and the other is that the air pull from the turbo brings the crankcase pressure in the engine down, up to a degree of course (the PCV closes to stop the oil being sucked from the engine). I have it on a graph in this video: kzbin.info/www/bejne/nmW3gmCOi7yIaZI. When you press hard the acceleration, the turbo kicks in and the pressure in the engine is negative, with respect to atmospheric of course. This really helps the gasses being drawn out. If it is left out, not connected, then the pressure in the engine is always high, long-term is probably not a good thing.

[@Neema1135514]

@@moremolecules Thanks for the reply. It would be fun to run the car as you did in the linked video, but with the return pipe disconnected and see what the graph looks like, if it will be constant all the time like in idle or if we see some difference.

[@moremolecules]

@@Neema1135514 Yes, I have not done that, but it will be interesting to see what the pressure is.

[@bobreese4807]

Very helpful video!!!!!

[@Wigwhom86]

How much pressure is too much?? 6 milibar is only 0.87 psi.

[@moremolecules]

I have answered that before and always gets asked. These engines max permissible pressure is 30-35mbar, so you can calculate how much is 6mbar out of that. The original Mann Hummel Provent 200 has a relief valve at the top that opens at 50mbar. So, 6mbar, if you engine is a bit on the worn side of things will get you quite high.

[@GrainGrown]

6 millibars is 0,087 PSI.

[@francisleonetti1120]

Diesels have higher pressures so does the Mishimoto standard can cause issues with non diesel engines?

[@moremolecules]

Well, not too sure, I suspect with the lower pressure petrol engines it woul be fine. It really depends on the blow-by of the engine. The higher the bow-by relative to a new engine, the more problems it will cause.

[@dieseltips]

Excellent work my friend. When you take out the oil filler cap do you see smoke and pressure coming out?

[@moremolecules]

Hi DieselTips, there is not much smoke and pressure coming out, of course there is some.

[@ZanSunstrider]

Nice video but im surprised you didnt test catch can with a breather on top if it :)

[@moremolecules]

Yes, good question. Simple reason I do not have one to test unfortunately.

[@YouTube--Video]

Danke super erklärt habe 👍 vielleicht habt ihr auch auf meine Frage eine Antwort??? es geht um den zwei Liter TDI..Macht es da Sinn eine Öl catch can zu montieren? Bitte um eine detaillierte Antwort. Danke schön

[@moremolecules]

It is worth it. At the end of the day, these direct injection diesel engines are designed the same way. You get some oily vapour coming from the breather/PCV/CCV valves to the turbo and air intake, which combines into pretty hard stuff with the carbon from the EGR valve. You also get some carbon deposits on the back on the intake valves. An oil catch catch should minimise the oil, so you only get carbon from the EGR. All in all is worth it. WHat is the efficiency is difficult to tell, do you get 15% of the oil in the oil catch can or say 80%? I do not know, difficult to tell. Probably somewhere ~20-30%, maybe less. So, does it make a difference, also difficult to tell, but probably it does. I saw that some people have fitted the 1.9TDI with oil catch cans, so I suspect the 2.0TDI is probably not too difficult to put an oil catch can to it. If you want to keep you car for longer, probably worth it, if not, then probably not worth it.

[@joshuagracias6354]

Thank you for an informative video, I have one question: I have a catch can with the bronze filter. The catch can is routed from my PCV to an intake vacuum line. The catch can also has a drain valve at the bottom. When the engine is running I have opened the drain valve and i can feel the strong suction. As long as there is suction is it safe to assume that there is no build up in the crank case pressure?

[@moremolecules]

Hi Joshua, no necessarily though. It only restricts slightly. In other words, if you did not have the oil catch can, the one with the bronze filter, the vacuum/suction will have been stronger. I assume your engine is petrol as diesels under idle will not have strong suction, but pressure. It is tough to say if the restriction is enough to cause problems, e.g. oil leaking past seals.

[@joshuagracias6354]

@@moremolecules I do have a petrol engine and yes agree, suction could be stronger without the bronze filter, but as long as there is suction the crank case is being vented, which shouldnt cause any pressure build up, do you agree?

[@moremolecules]

@@joshuagracias6354 Yes, the crankcase gasses get sucked out and pressure relieved.

[@michaelvanna8982]

Wow..very good info

[@jimsgaragetoys]

So from what I gather you are saying that the Mishimoto design is bad for diesels but for a gasoline engine it's not a problem? I have the Mishimoto on 3 of my cars and haven't seen any issues. My 2009 Corolla S is turbocharged and the crankcase is also vented with a filter so I would guess there is no problem at all with that set up. Did you also test a vented oil catch can? I also heard you say that this is an issue at idle and not at speed. Is that also true for a gasoline engine?

[@moremolecules]

Yes, the petrol/gasoline comment was a slip of the tongue. It would be similar to both. I did not quite say it is bad for diesels, only that compared to the others it increases crankcase pressure more substantially. Now it depends on the condition of the engine, if the engine is not a heavy breather then the slight increase in pressure is not that much of a problem. For some engines this increase in crankcase pressure could tip it to leaking from the seals. Unfortunately I did not test the venting to the atmosphere, it is illegal around here and I did not bother, maybe I should have. I have not tested the gasoline engines to check when is the highest crankcase pressure, but for diesels and I suspect petrol engines both would have the highest crankcase pressure at idle. It is just that under load the air flow (turbo or not) helps evacuate the gasses from the crankcase. I have not tested it but if venting to the atmosphere, you do not get this evacuation of gasses and it is kind of like constantly under idle or consistently under higher pressure, but might be wrong about that.

[@jimsgaragetoys]

@@moremolecules It would be interesting to see for sure in very controlled testing. I've seen a lot of people use the Mishimoto design and Ive not seen any people mention any problems. If there was a huge issue it would seem that this would be a known and highly talked about issue. I've seen information about using a vented system on pre-PVC car and a closed system on cars with a PVC valve. Your video make me have more questions than answers since I've never heard of this being a problem.

[@moremolecules]

@@jimsgaragetoys Many thanks indeed for the interesting discussion, much appreciate it. I only made that video because I did not know the difference between the different oil catch cans in terms of crankcase pressure. I really searched a lot for what is normal or usual crankcase pressure for my engine or any engine, because that is important in terms of how much more can you increase it with say the mishimoto oil catch can. I only found one single website for a mini cooper petrol engine and the reference value was ~30mbar. So, if this is anything to go by, the Mishimoto oil catch should not lead to any problems, as the overall increase in crankcase pressure if not that much as compared to the max 30mbar. The only problem can arise if the overall crankcase pressure of the engine is really high, say worn engine and it is close to the maximum. Then adding the Mishimoto could tip it over and lead to leaking seals. Now if an engine is that worn, I suspect that people will either recondition it or throw it away anyway. So, I suspect that most people just have relatively good engines and the Mishimoto would not cause leaking seals. Now an interesting question is, will the higher crankcase pressure cause any problems down the line. Maybe, but it is only a guess and it might not lead to anything overall.

[@jimsgaragetoys]

@@moremolecules Thanks, for your reply. I'm guessing that I haven't found issues with the OCC because the pressures were higher at idle and not while driving. I think of how little time my cars spend at idle so I'm not too worried. Thanks for your time and information.

[@moremolecules]

@@jimsgaragetoys No worries and thank you for the interesting conversation. I guess it will also depend on how worn the engine is. All the best