how many of you guys have oil catch cans?

Discuss the RB20, RB25 and RB26 series engines.
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ANVIL
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how many of you guys have oil catch cans?

Postby ANVIL » Mon Jan 07, 2008 7:50 pm

havent really heard much about them... is it worth it? which one do you have and how do you route the hoses? lets see some pics!


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Postby S12_hybrid » Mon Jan 07, 2008 10:16 pm

I've got one. They are easy to make. Ensure that you make the vacuum source NON-BOOSTED. By that I mean PRE turbo..

Hit up bings.ca, he's got them on for a good price.

-Dan

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Postby Bronze MFP » Tue Jan 08, 2008 3:49 am

I'd reccomend one as oil lowers the octane of your fuel if its getting sucked in the intake.I didn't have one and my intercooler ended up being my catch can. It had a good puddle in it after about a years worth of driving. I might have had a bad compressor side oil seal as well.

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Re: how many of you guys have oil catch cans? (ANVIL)

Postby Darius » Tue Jan 08, 2008 4:02 am

Search for catch can and you will find 50 threads.

With the obvious stated, I personally think they are good in theory, but don't know what percentage they actually trap out of vapor form during normal driving. However, after a day of street tuning, the catch can appears to accumulate some oil in it so it is probably doing its job.

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Postby gawdzilla » Tue Jan 08, 2008 5:46 am

just installed one last week, venting to atmosphere

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Re: (gawdzilla)

Postby bauchrb » Tue Jan 08, 2008 6:43 am

I've got a greddy 50mm or whatever size it is. Just put a slip in filter on the ex. side port, and you can reroute the tubing back into the intake after the MAF before the turbo, if you want to try and keep it smog... Or you can just vent it to atmosphere after the can.

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Postby Coolwhip » Tue Jan 08, 2008 7:41 am

I'm suprised Darius didn't say so, or even Karmin.

But from the sounds of it in this thread, the catch cans are being hooked up incorrectly without a proper vaccume source. By adding slip on filters and such.

For instance, think if you have one side of the T going to the intake behind the MAF, and the other side Venting to the atmosphere. So your not really creating a vaccume at all on the valve cover or the can rather just sucking in air after the MAF.

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midnightsliding
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Postby midnightsliding » Tue Jan 08, 2008 9:34 am

why don't RB people run them like this?

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Postby nizmo zilvia » Tue Jan 08, 2008 9:44 am

That pictures too shiny.

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Re: (Coolwhip)

Postby Darius » Tue Jan 08, 2008 10:23 am

Coolwhip wrote:I'm suprised Darius didn't say so, or even Karmin.

But from the sounds of it in this thread, the catch cans are being hooked up incorrectly without a proper vaccume source. By adding slip on filters and such.

For instance, think if you have one side of the T going to the intake behind the MAF, and the other side Venting to the atmosphere. So your not really creating a vaccume at all on the valve cover or the can rather just sucking in air after the MAF.
I haven't checked this thread for a while and am getting weary of repeating the same stuff over and over again, but yeah putting an inline filter from your dirty, oily catch can will only foul and plug. Then, it is even worse off than running it without a vacuum source. You can run it with a filter vented to atmosphere, but the filter will eventually clog and you'll be in the same boat. Mine plugged after one summer and started blowing blue smoke out the exhaust because it was causing my crankcase/valve covers to pressurize and cause oil to leak past valve seals and rings.

midnight - that is a good idea to run the valve covers through a couple check valves and directly into the exhaust. I've never even thought about doing it that way but it would definitely work and it wouldn't have to be routed through the engine at all. The only issues are getting materials/valves that can stand up to the high heat of the elbow and emissions if your state even cares.

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Re: (Coolwhip)

Postby bauchrb » Tue Jan 08, 2008 11:29 am

but doesn't the exhaust side vent just push air out whenever it needs to? I thought this was correct, if so then a filter on just that side should work...?I know people have been setting them up incorrectly alot, so I checked around to see, and was told by the guy at the dyno I had it plumbed correctly... I'll try to get a pic up.

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Postby Coolwhip » Tue Jan 08, 2008 12:07 pm

I've always been a fan of the 1 way check valve to the exhaust catch can setup. Supra guys pushing over 800whp find a HUGE jump in HP when setting up there crank case vent this way. When the turbo is pushing that much Air out the exhaust it creates a nice vaccume and seals the rings and valve seals so nicely.

How I plan on running mine is like this (sorry no picture yet since I'm at work):

Cross connection between rocker covers (might not though)

Run the T's to a catch can, with internal baffles and screening to knock oil from the vented vapor.

From the top/higher end of the catch can there will be a hose that routes to the exhaust with a 1-way check valve.

And at the bottom where all the Oil is colleting there will be a drain back to the sump to maintain proper oil management.

now people, thats a catch can set up.

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midnightsliding
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Postby midnightsliding » Tue Jan 08, 2008 12:59 pm

yea im goign to run the with like the pic i posted when i build my new car.

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Re: (midnightsliding)

Postby HxC_Nismo » Tue Jan 08, 2008 9:57 pm

that is funny i forgot about that using that setup instead of a normal catch can cause v8 drag cars have used that setup of alot of years and on our drag car we used that until we switch to a vacuum pump. only thing is i need to figure out the best way to do this on an rb26 with the stock twin turbos, cause i cant afford to switch to a big single right now cause im still paying off my credit cards that i used to complete my rb swap lmao

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Re: (Coolwhip)

Postby Darius » Wed Jan 09, 2008 3:11 am

bauchrb - It is okay to run a breather filter, but as coolwhip and others have said before, it is BEST to pull a vacuum on the crankcase for ring sealing and performance gains.

Coolwhip - It is a good setup with one exception. The oil drain line back to the sump is not going to work how you think. If it is valveless, then the exhaust will pull vacuum through the return line too. But if you have a valve on it, the catch can will accumulate oil and water vapor until you drain it. I personally would not drain it back to the sump because of the moisture content of it. Stock is setup so the water vapor from condensation inside the crankcase is burned in the engine so it does not accumulate. A catch can, however, will not allow this "purging" unless it happens to pass randomly into the exhaust. If anything, drain it into your exhaust

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Coolwhip
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Postby Coolwhip » Wed Jan 09, 2008 4:05 am

Hmmm, I'm still working on the specifics and the considering the physics of the described setup. We'll see

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Postby Bwana » Wed Jan 09, 2008 4:38 am

I'm going to run mine straight to the downpipe. There's 0 drawback to doing it ,it's extremely effective and no catch can needed.

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Re: (Bwana)

Postby Darius » Wed Jan 09, 2008 5:11 am

The only question I have with doing this is how will it affect tuning with a wideband O2 sensor? Will it even be enough to worry about affecting the reading or are we back to square one with installing a catch can?

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Postby Coolwhip » Wed Jan 09, 2008 7:35 am

another draw back to running it through the exhaust is that:

1. You will get blowby/oil in and out your exhaust.

(Not that its a major concern or problem but when you have oil coming out your exhaust you usually go straight to your turbo or compression test your motor.) With alot of blowby you wont' have the pleasure of figuring out a upcoming problem that exsist.

2. You don't know how much blow by your getting. Or how much oil your loosing though the exhaust. For instance, if your rings or something else is going bad and creating alot of oil blowby you usually can tell by your catch tank being full of oil (and of course a crappy performing motor, lol). If you just pull it out the exhuast you'll be clueless untill you check your dip stick. And that can tell you either your burning oil, leaking oil, or blowing it out the crank.

But I still like using that method! :P

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Re: (Coolwhip)

Postby sil_eightyRPS13 » Wed Jan 09, 2008 2:34 pm

Coolwhip wrote:another draw back to running it through the exhaust is that:

1. You will get blowby/oil in and out your exhaust.

(Not that its a major concern or problem but when you have oil coming out your exhaust you usually go straight to your turbo or compression test your motor.) With alot of blowby you wont' have the pleasure of figuring out a upcoming problem that exsist.

2. You don't know how much blow by your getting. Or how much oil your loosing though the exhaust. For instance, if your rings or something else is going bad and creating alot of oil blowby you usually can tell by your catch tank being full of oil (and of course a crappy performing motor, lol). If you just pull it out the exhuast you'll be clueless untill you check your dip stick. And that can tell you either your burning oil, leaking oil, or blowing it out the crank.

But I still like using that method! :P
the problem with that 2j u posted, is that the check valve has to be placed at the end of the downpipe, so it can built vaccumm...and u can run a line to a catch can and then to the downpipe, so u can see if u are infact blowing by...i am running it this way as it is the best way, and as stated above, u do gain Hp with 500+hp cars...


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