Catch Can Thoughts

[TheRoyalStig]

Has anyone looked at the Catch Cans on Amazon? They are 1/10 the price of Mishimoto!!
https://www.amazon.com/AOCISKA-Aluminum-Reservoir-Separator-Universal/dp/B0BVB88RPZ/ref=sr_1_4?af=eyJ2ZWhpY2xlTmFtZSI6IjIwMjQgTmlzc2FuIFoiLCJ2ZWhpY2xlIjoiMjAyNC02Ny0yOTkyNy0tLS0tLS0tLS0tLTEifQ==&crid=359DXLLU9BNPC&dib=eyJ2IjoiMSJ9.o8GjI9YFdo64JwDDUH-rkfeJUaEwQB-L4i6IIJspqCv5t3O1d45oxz0dWtEf1_OPjgWRUcNnNLW1r8n_ftyNuO9JeSfcschvXLE-djhiBy9sFTDCU4feve6kyWekPTzCVhi733iQw5NN4ezLg1uRuw.qf0-Vb5ZXNBWSk716yEmZ4dKNXCzvLUy6j2_U1dOT4I&dib_tag=se&keywords=mishimoto+oil+catch+can&qid=1757992282&sprefix=Mishimoto,aps,120&sr=1-4&vehicle=2024-67-29927------------1&vehicleName=2024+Nissan+Z&th=1

The Mishimoto kit has all hardware for installs specific for the Z with all mounting brackets, pre-sized hoses and instructions.

At the very least with that one you will want to get better hoses as well. So yea, if you are ok figuring out your own mounting and hoses it should be ok based on reviews? Quality is lower. Will require some extra work and effort. If that is worth saving a few bucks that it may do the trick.

 

[Xylander]

Catch cans are BS nonsense. If you call me out on this, I have engineering degrees and would love to expand as to why this is in more detail. All you need to know is that 99.99999999999999% of the oil a catch can collects is because they put a catalyst in the dirty side of the PCV system and it's forcing what is normally aerosol-based oil vapors to condensate into liquid oil. That oil aerosol would normally pass unimpeded through the engine and get collected in the catalytic converters. Thus, catch cans only catch oil because they "fix" a problem only they create.

 

[5amp5on]

Catch cans are BS nonsense. If you call me out on this, I have engineering degrees and would love to expand as to why this is in more detail. All you need to know is that 99.99999999999999% of the oil a catch can collects is because they put a catalyst in the dirty side of the PCV system and it's forcing what is normally aerosol-based oil vapors to condensate into liquid oil. That oil aerosol would normally pass unimpeded through the engine and get collected in the catalytic converters. Thus, catch cans only catch oil because they "fix" a problem only they create.

So I have a 0.00000000000000001% cleaner combustion chamber (validated by an engineer), a cool looking Mishimoto catch can that gives me something else to play around with on my Z, I know how to take off my intercoolers now, and I get the satisfaction of dumping all the gunk every couple of thousand miles. Sweet.

 

[VR30Infection]

Catch cans are BS nonsense. If you call me out on this, I have engineering degrees and would love to expand as to why this is in more detail. All you need to know is that 99.99999999999999% of the oil a catch can collects is because they put a catalyst in the dirty side of the PCV system and it's forcing what is normally aerosol-based oil vapors to condensate into liquid oil. That oil aerosol would normally pass unimpeded through the engine and get collected in the catalytic converters. Thus, catch cans only catch oil because they "fix" a problem only they create.

Sorry buddy but the back of the intake valves on a direct injection engine as well as the intake runners completely disagree with you. It is absolutely in the form of vapor however it totally collects on the back of the valves and bakes on. Now, on a wet manifold system this is not the case because the atomized fuel washes everything off. On a DI engine however it gets pretty crusty. The catch cans do help keep the valves clean.

Oh, and this is not my attempt to “call you out”. If you do want to expand and give proof that would be great however I’m not here to get into a pissing match with anyone. Just here for fun, to gain knowledge and to hopefully help others. Be part of the community.

 

[T3R5Z]

I'm going to be installing a catch can my cars brand new have not even done the first service yet.

Obviously the catch can doesn't catch everything. From my understanding it doesn't work when the car is on boost? Not sure how that works.

I'm thinking of also using CRC valve cleaner every 10,000 KMs 6000 miles as another prevention method. Anyone else do this?

 

[VR30Infection]

I'm going to be installing a catch can my cars brand new have not even done the first service yet.

Obviously the catch can doesn't catch everything. From my understanding it doesn't work when the car is on boost? Not sure how that works.

I'm thinking of also using CRC valve cleaner every 10,000 KMs 6000 miles as another prevention method. Anyone else do this?

The PCV valve (positive crankcase ventilation)is a check valve. When there is vacuum in the intake manifold, the PCV is open and the manifold is drawing crank case “air” through and then combusting it. When the car is under boost the check valve is closed otherwise the crank case would be pressurized by the 16 lbs of boost that is in the intake manifold. This would be bad news.
The other piece of this puzzle is that there are other crank case vent lines that are connected to the intake pre turbo so as the turbos spool up they are sucking in this crap. Good for ring seal but bad because we have direct injection. This is a forever argued about situation (weather or not there are power benefits) A lot of the big power GTR guys vent all of this to atmosphere. There are GTR kits out there to do so. Some hot rod guys run a line into the exhaust pipes at an angle causing a Venturi effect, thus drawing out all of the gases and what not that are in the crank case and putting a vacuum on the crank case to help the rings seal better to help build more power. If I remember correctly we have 3 lines that pull from the valve covers to keep pressure from building in the crank case. In a perfect world we would keep all of this crap out by way of venting or catch cans. Again. Absolutely none of this would matter if there was port injection blasting the runners and back of the valves with atomized fuel. But. With direct injection it gets really bad over time.

 

[Xylander]

Sorry buddy but the back of the intake valves on a direct injection engine as well as the intake runners completely disagree with you. It is absolutely in the form of vapor however it totally collects on the back of the valves and bakes on. Now, on a wet manifold system this is not the case because the atomized fuel washes everything off. On a DI engine however it gets pretty crusty. The catch cans do help keep the valves clean.

Oh, and this is not my attempt to “call you out”. If you do want to expand and give proof that would be great however I’m not here to get into a pissing match with anyone. Just here for fun, to gain knowledge and to hopefully help others. Be part of the community.

And, I've had direct injection engines with >250,000 miles on them with crusty valves and they work just fine. I've worked on thousands and built hundreds of race engines (I have never worked on consumer grade cars... SCCA class builds mostly). Not once in over 20 years in business did I see an engine come in for service caused by oil deposits on valves... when there wasn't a mechanical failure further up in the chain that caused an actual problem. But, never in 20 years have I seen an engine fail caused by nothing more than a few microns of carbon buildup on a valve. It just doesn't happen.

Now, is it possible that it could happen? Sure... but not in 100,000 miles unless someone's doing something stupid like running a ghost cam tune. For a street rated performance car, I personally budget for an engine rebuild every 100,000 miles. My C8 only ended up with about 30k miles and I rebuilt it twice. Once for a blown ring on number 7 and again for a courtesy refresh when I sold the car. It ran somewhere around 200 laps under competition across 2 years of ownership. It too was a direct port injection engine. The valvetrain had some small buildup, but it was starting to show wear on 5 cylinders during leakdown testing. So, while the car started to show head gasket issues after 2 long years of competition, the catch can-less engine had no real signs of wear in the valvetrain caused by buildup... and the C8 has a dry sump system that's known for flooding the cats and O2 sensors with oil blow by under extreme conditions. Even that thing didn't wreck the valves.

Totally unrelated, but my Nismo Z here in total showroom spec turned a lap at Talladega Grand Prix last weekend that was 1.3s faster than my personal best in my old C8 Stingray 2LT. The C8 lapped that time on Goodyear Racing Eagles. The Z is a delightful car to sling around a tight course like that.

 

[VR30Infection]

I see your point about how you have not experienced an engine failure due to carbon buildup in the intake runners and back of the intake valves. I don’t think I was worried about engine failure as much as just cleanliness. I hadn’t really thought that far down the road. If a cheap catch can purchase will help, I don’t see the harm. That’s all man. Personally I’m not going to throw mine in the trash because of the examples you’ve given.
On the other note, I’m stoked to hear that your Z is happy on the track. That’s awesome.

 

[Hernandooo]

Catch cans are just a preventive measure, soo you don't have to end up cleaning the valves with crushed walnut and compressed air

 

[Stefanovich]

Catch cans are just a preventive measure, soo you don't have to end up cleaning the valves with crushed walnut and compressed air

Well said mate, totally agree, anything that helps cuts down the carbon build up is worth every cent. Too much BS on these forums.

 

[Xylander]

Well said mate, totally agree, anything that helps cuts down the carbon build up is worth every cent. Too much BS on these forums.

Well, just don't go looking into the oil return journals anytime soon