hey all

this wknd i'm going to do a proper oil catch can setup with return line to the sump. I'm off to Oran Park next wednesday for a track day so i dont want the same thing to happen to me that happened at our MM08 wakie day earlier in the year. Now i'm after suggestions on how to do it right, what i can and can't do etc.

The plan is to plumb the catch can into the sump, so sump off to install a dash 6 or 8 fitting. Also plan to plumb the s/c return line into the same line so it no longer drains into the rocker covers as per sprintex setup. I want to turf the line that joins the front a rear rocker covers and make individual lines to the oil can.
One question i do have is in regards to the PVC valve on the drives side of the car. Can i completly get rid of it and block the holes? is it needed? It does look like a pretty crappy platic item to hold back 10psi entering the rocker covers.

any suggestions on the best setup possible for my needs would be great.

Cheers, Jase :D

Why not just T piece that little one from the front into one of the main blowby lines with a magnaflow coupling?

Why not just T piece that little one from the front into one of the main blowby lines with a magnaflow coupling?
please explain?

please explain?

Well the way you explained it you are running hose from each of the rocker covers to the catch can correct? also the oil return line from the blower correct? so with the PCV valve from the front run that hose to the front rocker cover hose and T piece it there.

I know this won't help you Jason but for others who are contemplating an oil catch can, this is how mine is set up:

http://img.photobucket.com/albums/v124/mohit/Verada/catchcan01.jpg

Breather hose from rear rocker cover feeds into the can, and another hose goes back into the intake pipe. Since that pic was taken i've cleaned it up a bit by running the hoses below the MAF.

at the moment all im running is a pipe from the rear rocker cover to the can, but no return line just a little K&N filter. When heavy cornering and high revs combine, the can has been filling up hence the need for the sump return line.

I have my Catch can plumbed in the same as Mohit. Off the rocker into the can, then off the can into my induction pipe.

Will the oil actually return to the sump? Crank case pressure might be too high? If you're going to do it this way.. is there a need for the can itself? :s

Will the oil actually return to the sump? Crank case pressure might be too high? If you're going to do it this way.. is there a need for the can itself? :sits a place to collect and vent presure. Also the return line would be placed as high on the sump as possible so it should just drain back in. Note the charger and can lines will enter as one.

Will the oil actually return to the sump? Crank case pressure might be too high? If you're going to do it this way.. is there a need for the can itself? :s

Bingo. The name of the can gives it all away really. Is there provision for a drain hose in your catch can Jase?

The oil will drain back to the sump as proposed BUT the crankcase pressure wont go anywhere! That's the drama.

Bingo. The name of the can gives it all away really. Is there provision for a drain hose in your catch can Jase?

The oil will drain back to the sump as proposed BUT the crankcase pressure wont go anywhere! That's the drama.
yeah there is provision for a drain.

the s/c return line would return under presure, not sure if that would help the situation

The main function it to have the crank case at a normal pressure so it has a line running into the air intake, if you plumb this back into the sump the pressure will not be released.

after reading some of the posts you just need to remember guys that there isnt much oil going through the can.

a well maintained engine is lucky to put through 30ml in a 10,000km service period.

A drainback isnt really necessary but a line from the crankcase to the catch can is a good idea, since the catchcan will eventaully run into the inlet.

drainback and pressure can be accomodated through the same fitting in the sump, just make sure its above the level of the oil in the sump at all times.

The head and block share pressure through the internal oil drains anyways so a specific pressure line from the crankcase is not needed.

i would have large bore (10mm) fittings welded into each rocker cover. block off the pcv and remove it. have a drainfitting iin the sump mate up to the bottom of the catchcan and be of large size (20mm) with best posible gravity feed. Both lines from the rocker cover would go into the catchcan roughly 2/3 the way up the can and a single line from the top of the catch can (12mm) would do to the inlet just before the throttle.

Its a bit overkill, but you wont have any trouble with the breather system pressurising and pushing ya dipstick out while on the track. Your engine is only going to breathe more and mroe the harder and longer you drive it, so you wont need to be replacing it anytime soon.

Know what's funny? My work car, a 4x2 2008 3.5L V6 Triton has a factory catch can, only noticed it the other day when filling the wiper reservoir. It's plastic and black too, almost invisible with all the spaghetti under that bonnet.

the factory catch can you speek of NICK is not serving the same purpose as the aftermarket items people like to use. The 'catchcan' you speek of is in reverse use, in that its purpose is not to catch the oil blown out of the rockercovers when the engine is breathing heavily, its there to stop oil making its way from the crankcase to the inlet via a bad breather system/blown ring when the engine would be breathing heavily.

technically its a catchcan but more technically the aftermarket items are air/oil seperators but its much of a muchness.

the best specific difference is a stock catchcan will nigh on always be between the crankcase breather and the rockercover (if t-pieced like on most inline engines) or between the crankcase breather and the inlet. You would probably notice the stock catchcan you speek of sits between the crankcase vent and one of the rockercover breathers, and this breather then continues onto the inlet

aftermarket items are always best situated before the inlet, so there are no more sources of oil that can enter it before the air/breathe from the engine returns to the inlet.

I also forgot to mention before, i have no specific knowledge of superchargers, but like turbochargers i would bet the oil return from the supercharger is gravity drain and not under oil pump pressure.

i would have large bore (10mm) fittings welded into each rocker cover. block off the pcv and remove it. have a drainfitting iin the sump mate up to the bottom of the catchcan and be of large size (20mm) with best posible gravity feed. Both lines from the rocker cover would go into the catchcan roughly 2/3 the way up the can and a single line from the top of the catch can (12mm) would do to the inlet just before the throttle.

Its a bit overkill, but you wont have any trouble with the breather system pressurising and pushing ya dipstick out while on the track. Your engine is only going to breathe more and mroe the harder and longer you drive it, so you wont need to be replacing it anytime soon.
Thats exactly what i wanted to know thanks. Its the same as what i was thinking but just wanted to confirm it with someone else before going nuts with it.

the factory catch can you speek of NICK is not serving the same purpose as the aftermarket items people like to use. The 'catchcan' you speek of is in reverse use, in that its purpose is not to catch the oil blown out of the rockercovers when the engine is breathing heavily, its there to stop oil making its way from the crankcase to the inlet via a bad breather system/blown ring when the engine would be breathing heavily.

technically its a catchcan but more technically the aftermarket items are air/oil seperators but its much of a muchness.

the best specific difference is a stock catchcan will nigh on always be between the crankcase breather and the rockercover (if t-pieced like on most inline engines) or between the crankcase breather and the inlet. You would probably notice the stock catchcan you speek of sits between the crankcase vent and one of the rockercover breathers, and this breather then continues onto the inlet

aftermarket items are always best situated before the inlet, so there are no more sources of oil that can enter it before the air/breathe from the engine returns to the inlet.


Was just saying man..


I'm gonna go stick a nismo sticker on it or something.

i wasnt having a go NICK mate, just thought i would explain them all. These mods are trivial to a stock car, but there are always ill-informed persons who wish to undertake it and all they need is a little misunderstanding or misdirected info and it leads to another thread about the same topic and so forth... wanna see repetition, check out NS.com

Just pointing it out for the people mate, good to see you mention it, as now i think about it, my car had one aswell when it was stock (sr20 S13)