ok, ive had this issue for AWHILE now and its carried over 3 motors, and 3 different turbos. i dont have the stock catch can, but i do have an aftermarket one istalled between the valve cover and intake behind the MAF. if i stay out of boost or only hit light boost no matter the rpm, the catch can will have NO oil in it. 5-6 WOT pulls and the can is almost full. ive been beating my head for months and i cant figure it out. like i said multiple motors and turbos. the current motor has around 4k since i rebuilt it. compression is 165,165,168,164. i dont have a leak down tester, though i may invest in one soon. ive changed the pcv and the valve cover. i went over all the clearances over and over during the rebuild, everything was well within spec. Ideas???

Do you have any kind of air/oil separator between the block outlet and the T in the valve cover? The other side of the T has the catch can, but I'm talking about where the factory air/oil separator goes. If not, it's most likely not blow-by, but the fact that you aren't separating the oil from the air that is going to the catch can. S13 SRs are very poor at doing this in the first place, so you have to "do a little extra" to get it working properly, lol.

no i sure dont. that makes sense. i have an aftermaket manifold and didnt have room to put the stock can back. its just a hose from the block to the valve cover. ill dig out the old can and try to fit it up and see what happens. i did try moding the valve cover in a select few spots and have cut down on the amount of oil but its still blows a good bit out

I went to an S14 valve cover, and now everything is bone dry, with awesome ring seal, lol. I highly recommend going that route for cleanliness and how effective it is.

how did you make that work with the vtc spot on the valve cover?

i just looked it up....... i like that....

rustest86 wrote:i just looked it up....... i like that....

Lol, yup, you have to cut the S13 front off and weld it on. It works like a dream though, and looks nice as well, which is a nice bonus.

i really like the idea, but im a diy kinda guy. im gonna try and mod an s13 cover to do close to the same thing since i have 3 laying around

i just wanted to update this thread, i did fix my problem with a much cheaper solution than the s13.4 mod.

cost the right around $60 and havent had the first drop of oil in the catch can and looks much better!!!

Did you weld in a bung or tap some threads?

and can you take a closer pic of the side of it?

im thinking of during this

no problem,




i had 2 10an fittings welded on and my problem has been gone. ive probably put 5k on it since doing this and have had zero oil in my catch can.

Awesome man thankyou

Now you aren't pulling any pressure from the crank case though... That was the entire reason for the T in the first place.
It uses the vacuum to reduce crank case pressure.

He is still pulling pressure from the crankcase. There is a line between the VC and the crankcase, and a now separated line from the VC to vacuum. With the "T" they are just connected at the same point. This way, the oil from the crankcase goes to the valvetrain rather than directly into the vacuum source. It's essentially what the S14 VC does, but there's no baffling between the two ports. However, the valvetrain will act like baffling, lol.

You stole my idea!!! Lol, this is excactly what I've been planning on doing to mine. Glad to see that it actually works.

Yes it still pulls vac on the crank case, just all through the valve cover now kinda like a KA does. the valve cover has a built in oil separation system built into it under the riveted metal plate. i tore a junk cover apart to make sure and plan this out before doing it. lol idk about stole........ but your more than welcome to use the idea!!! that what these forums are for. it works great and looks great too! not to mention easier to work on. ZERO oil in the catch can now and im running a HKS gt2530 @17psi. its roughly a bit bigger turbo than a s15 unit. motor has around 7k on it now, and the turbo has unknown mileage but prob around 20k now. it gets beat on and sees 8k daily to and from work. being all that, im very happy with the results for $60!!!!

I already have my an fittings and spark plug tube seals, just haven't had the chance. Glad to hear you still have no oil! I'm planning on drilling out the exit larger though. Where the old t went, the exit hole isn't very big. I'm also going to turn the pcv exit into a catch can line (and very trickily keep yhe pcv) and shoot for some crazy psi. Lol. Next setup my goal is 40+ psi. :-)

Just wondering if you're getting any oil at all. Thinking about just skipping a catch can If its efficient enough setup.

still zero oil in my catch can, now even have a blown ringland/baked rings/or blown headgasket. i have 125, 125, 123, 79 compression. even with that, still zero oil. been very happy till a week ago. motor got badly overheated when a hose blew out under the manifold, fixed the hose and still driving it just not quite as hard. oh well. time to build my other block up.

Nice to know! And sorry to hear that. I think I'm just going to run no catch can then. Seams to be tested and proven. I may just run a breather but I'm kinda liking the idea of at least going back to the intake.