Catch Can (Yep here is another thread on it)

[David Montgomery]

My question is different, though. The Mishimoto can is installed on the driver's side of the intake. Does that mean that only the blowby oil is being captured on that side of the engine only? Forgive my ignorance; I be but a humble old timer who has spent his life wrenching on an S130 L28T. As I like to say, being an old Datsun Z fan... Give it to me straight (anybody see what I did there)?

 

[FSUZ33]

From what I understand most of the crud gets blown through the driver's side. But you are correct, technically for best results you'd want one on both sides.

 

[Tranzor Z]

If catch cans worked I'd imagine a car manufacturer would install them. Calling total bullshit on this mod.

 

[chadgigachad]

If catch cans worked I'd imagine a car manufacturer would install them. Calling total bullshit on this mod.

The average joe can barely keep up with oil changes, and it takes 10s of thousands of miles for carbon deposits to become a problem. Not surprising that automakers won't install them.

 

[FSUZ33]

They do work, or they at least slow down the formation of deposits.

It’s bowing to the MPG gods and going all-in on DI, and ultimately not caring that the engine is going to gunk itself up, ultimately losing power and therefore MPG over time. Govt’s and manufacturers only care what MPG it produces when new. Probably impossible, but I’d like to see the same engine, one DI and the other PI, and their power and MPG new, then at 50K mile intervals. I assume the overall MPG will be better with the PI engine over time, annd ultimately better over the life of the car…assuming the norm, that the DI owner doesn’t get a multi-thousand dollar valve cleaning every 40K mikes.

Cars are throways now. The infatuation with EV’s proves it.

Edit: Through exhaustive research (i.e one google search) it appears walnut blasting runners/valves is supposedly $500-$800. I thought it was more than that.

 

[KrackaC8]

Solution looking for a problem...

 

[HWill]

I have always had catch cans on my vehicles. Definitely recommended for forced induction vehicles. And there are certain manufactures that make catch cans for their vehicles....FORD.
I used Ford on a Mustang and Bronco.

I did have a two can system and the second can was always empty for me on an NA Mustang, but they say you will pick up some oil in it with FI.

Wish there were better options for the Z.

 

[el mágico]

I saw this awhile back. (See YouTube link below). This guy installed a second catch can on his heritage.

 

[haohmaru]

For DIT motors like ours, I would say catch cans are very helpful in preventing carbon deposits. The oil I drain from the can is oil that doesn't end up in the intake manifold and valves.

 

[David Montgomery]

Thank you all for your posts. I love the spirited dialogue. Back to my original question. Does the Mishimoto catch can only capture oil on one side of the engine?

 

[KrackaC8]

Just a quick word on on catch cans and the "oil" they're "catching"...

Catch cans increase restriction on the crankcase ventilation side and often times create additional crankcase pressure, requiring more pumping force from the engine to overcome. This eats into horsepower. Back in the day I did some dyno testing on the Evo 8/9/X platforms and found it to be a 20whp difference on one particular setup that immediately comes to mind. A car I was working with was down on power and not making what it should... I disconnected the brand name catch can setup, reverted the PCV system back to stock, and the car immediately picked up 20whp and ran smoother.

Another thing to consider, most of this oil that the cans are catching normally remains in vapor state and burns through the engine without issue. The reason the cans are catching "oil" (actually a mixture of oil & water vapors) is because they slow down the ventilation process allowing time/restriction to cause cooling so the vapors reenter a liquid state.

Not trying to talk anyone out of something they view as beneficial, but just another perspective to consider. Happy modding!

 

[VR30Infection]

To answer the original question. Most of the catch can setups for us are only catching the PCV line. Connected to the PCV valve which is on the driver side valve cover and then is connected directly to the intake manifold. This only works during a vacuum state (meaning it does not work during boost as the PCV is a one way check valve setup) When the manifold sees boost, the PCV valve is closed otherwise you would be adding boost pressure to the crank case. This would be bad. The passenger side line is connected to the passenger side valve cover and then goes into the intake tubing PRE turbo. So as the turbo spools it is sucking air from the crank case. The higher the boost and therefore higher likeliness of positive crank case pressure, the harder the turbo is sucking on that line to keep things okay. This is why you would see some oil pooling on the passenger side turbo but not on the driver side. Technically speaking, you would want both sides done to mitigate the buildup on the back of the valves and whatnot. From a performance perspective on the vr30, if there were to be any performance loss of any kind it would be related to the passenger side system if the catch can setup was a restriction not allowing the suction to even out any positive crank case pressure. As far as the PCV side is concerned, there is no way for a catch can to hurt performance numbers due to the fact that you are not building power while the intake is under vacuum. This is only during idle and light cruising where the engine is not under any load whatever. (I hope this helps)

 

[TheRoyalStig]

If catch cans worked I'd imagine a car manufacturer would install them. Calling total bullshit on this mod.

So whether they work or not this is extremely flawed logic.

Manufacturers would install them if the cost to do so outweighed a cost it was solving.

And cost would be developing a system that held much more oil than aftermarket ones do. Which involves not only the cost of hardware x vehicles sold but the development time, reorganizing already cramped engine bay space and making sure it is as dummy proof as possible for the average person not paying attention.

The cost this would need to offset is the cost of stock engines that have an actual failure due to blow by within the warranty period.

And those are not the reasons anyone is installing them for.

Things can work and make sense for the aftermarket/enthusiast space and not make sense for manufacturers at the same time.

 

[FSUZ33]

There's also the angle that manufacturers don't want to add things to cars that are deemed another regular maintenance item. Not sure how much that factors in, if at all.

 

[Tranzor Z]

So whether they work or not this is extremely flawed logic.

Manufacturers would install then if the cost to do so outweighed a cost it was solving.

And cost would be developing a system that held much more oil than aftermarket ones do. Which involves not only the cost of hardware x vehicles sold but the development time, reorganizing already cramped engine bay space and making sure it is as dummy proof as possible for the average person not paying attention.

The cost this would need to offset is the cost of stock engines that have an actual failure due to blow by within the warranty period.

And those are not the reasons anyone is installing them for.

Things can work and make sense for the aftermarket/enthusiast space and not make sense for manufacturers at the same time.

I work with couriers all day. Most of these drivers have 200k miles or more and been reliable trucks and cars. I've seen some drivers with 500k miles. None of these people have ever used or probably even heard of a catch can. This is just my opinion but I think they were created and a trend followed, nothing more.