Catch Can Crankcase Ventilation

[krarks]

Frankiman's setup is pretty nice, his valve covers are way nicer then they used to be and they were nice in NUR gold.

Anyways if your engine is older then run it like Frankiman's, on a fresh rebuild vent the blow by gases to the atmosphere. It might smell a bit in traffic but at least that 93 or 94 octane that you pay extra for doesn't end up being 87 octane because its full of oil vapors. IMHO if your car is not a track whore then just leave the stock setup or get a Nismo Oil/Water Separator.

So if were aren't tracking our cars, you'd suggest not getting a catch can and get the separator? (and that Nismo separator is over $500 CDN lol while a catch can is under $200)

Just looking at doing a catch can or something at the moment and looking for more info as what to do. My skyline is just a DD but I don't want to worry that if I push it to hard about all the blow-by oil going back into my i/c, maf, etc...

[mitch32]

Nismo oil/water separator is the optimal thing but if you don't want to fork over the 500$, then go for a baffled catch can and plumb it back into the intake system.

You shouldn't have much blow-by if your just cruising or city driving. Its when you push the car that there will be blow-by but there should never be so much that it clogs up the intercooler. If you have a lot of oil in your piping means either you just never cleaned your piping ever, or something in the engine is failing or the turbo is finished.

[frankiman]

So if were aren't tracking our cars, you'd suggest not getting a catch can and get the separator? (and that Nismo separator is over $500 CDN lol while a catch can is under $200)

its the exact opposite

[krarks]

So get a catch can if just DD? To just be clear haha.

[frankiman]

yes

[GTRSOAR]

Hey guys, ive seen about 9 different ways to hook these things up. I hope I did mine proeprly. My mechanic who also owns many JDM cars including a R32 GTR has his hooked up like this. (This pic is of my car) This is one of the correct ways?




Both ends are capped but one is covered (The one that's right after the filters)

Thanks in advance!!

[GTRSOAR]

Sorry about the dust, shes hibernating for the winter :P

[DreadedFist]

Super Duper Dreaded Fist Catchcan Setup

What: How to set up a catchcan properly and legally (prevents harmful emissions going into the atmoshpere)

Why: Prevents oil from coating intake system. Oil reduces the octane rating of the fuel.

How: See picture + steps.



Above is a legal catchcan setup, that does not vent oil to the atmosphere. It also doesn't allow oil to coat the inside of your intake system. Pictured is an RB20, difference between the 20/25 and 26 is the location of the pcv and te location of the breather fittings on the valve covers.

You want some kind of suction in the can, or else it won't be doing much. To achieve this, we hook it up to the intake pipe after the filter and MAF. Depicted in the catchcan at the lower right is steel wool, which is held in a stocking. This seperates the oil from the air, allowing air to pass through, but not oil. The little wave at the bottom is, you guessed it, oil.

If you have a catchcan that has nothing in it, it's not doing anything. If you have an empty can plumbed back into the intake pipe, oil is still being sucked into the intake. The steel wool inside of the can prevents this (some oil will still probably get through, just not as much).

By recirculating the gases back into the system, you are still legal, as nothing is being vented to the atmosphere. By preventing the oil from being sucked back into the system, you are no longer shooting oil into the intake system. Depending on blowby levels in your engine, you may never find oil pooled in the bottom of the catchcan, or, if your engine is nearly dead, it might fill up quickly.

Since we're all about remaining legal and friendly to the enviornment, we make sure that the oil in the catchcan is properly disposed of at the appropriate locations (read: not in the storm drain).

Leave the PCV system alone with this setup.

If you disagree with this setup, you may tell me what an idiot I am.

[bellis_GTR]

Wow great write up mate. I will now know how to set up my catch can properly. Thanks for the short detailed How-to.

[GTRSOAR]

How long until I can expect to see some oil on the level indicator in the catch can? I know it depends on how often/hard you drive but on average. A few hours of driving? A few weeks of driving? Is my set up good? Thx for the help

[GTRSOAR]

Is the setup good in comment #36?

[GTRSOAR]

KK here's the new set up. SHOULD be the best way to filter fumes during boost AND during idle. The hose right after the air filters is capped too. Nice and simple too, Thoughts?