Did I do this right? If so then I don't understand where the blow by goes? I mean if I block off the bottom nipple and have the hose running from the tid to the oil filler nipple then where does the it go? Also as long as I've been on this forum I've never seen anyone else running this same setup from the tid to the nipple or am I just blind. I have no emmissions so my pcv valve is completely gone. Thanks for any help. Here are some pics to show yall what I did.

 

I've never done the removal, but had this information. Also not certain as to the amount of oil that would be sent into the can. Looks like the vent line is into a catch can:
PCV SYSTEM - This is the Positive Crankcase Ventilation System, which is there because the oiling system generates pressure which needs to be bled off - it can't be a sealed system. Stock, the system is fed back into the intake, and some residual oil is pulled into the intake, dirtying intercoolers and throttle bodies . On the TurboII, the nipples to be concerned with are just below the oil fill cap, and where the oil fill neck meets the block. This HAS to be vented - if you cap it up, you will pressurize the crankcase, which can lead to smoking and all kinds of weird problems. Venting it to atmosphere is the easiest solution, but will over time make a mess, as excess oil comes out of the nipple. The right way is to use a catch can that has a filter on it to catch the excess blow-by. Jaz makes a tiny catchcan that works great - Jeg's carries it.

 

so I shouldn't hook the line from the tid to the upper oil filler neck nipple? or should I? And like I said I capped the bottom nipple as well.

 

I'm in work and it's difficult at times, but if this helps, Sure Shot wrote the following which does come from the top nipple to the canister which he's using as a catch can. As it fills, he just replaces the canister.

"I am using the old charcoal canister with some of the origonal hose & pipe directly from the top oil filler neck nipple".

 

you know I've heard of people doing that. I may give that a shot however my charcoal canister and lines are long gone I might as well just get a catch can. I just kind of need to know if the way I have it will work temporarely or not? So I don't mess up anything, lol.

 

thats the same way i did mine but i didn't route mine back to the tid though. just let the hose drop by the spark plugs

 

see thats what I did before however some people where telling me to do it like this for better ventalation???

 

anyone?

 

What you've done is fine, except that you've only done one of the two crankcase vent nipples. The other one is on the center housing under the oil filler neck. This won't work as well as the stock system though, because the vacuum in the TID is only far less that the partial manifold vacuum used in the stock system.

However most people try to avoid putting this blow-by back into the engine. It is done by the factory purely because it is illegal to vent blow-by to the atmosphere, but it has obvious downsides for performance. An oil/air seperator should be used in a set-up like yours, so that only air gets sucked into the intake. Or you can just run two hoses from those nipples under the car and leave them open-vented.

 

https://www.rx7club.com/forum/showth...39#post2138239

Wouldn't that cause the white foam on the oil cap?

 

thanks nz for the help. The only reason I'm hooking it up like this is because it is supposedly "better" for crankcase ventalation however the old way I did this was exactly like you said I had both nipples running to vac lines that where running to the side of the engine ...... as a matter of fact I believe you where the one that told me to set it up like that in the first place I will probably set it up like that again instead of the way I have it if it is better than I have it now. Thanks again!

Edit: oh just reread what you said and do you think I shouldn't black off that nipple but actually run a line from the tid to the upper oil filler neck and then the bottom nipple? THanks.

 

I have a diagram that shows the oil filler neck vac line going to the metal line to the charcoal canister and the intake line going to a oil catch can then to the charcoal canister, could I just hook it to the charcoal canister??? I also have a diagram showing the intake line caped??

 

It is, because there's always a little bit of vacuum applied to the crankcase.

How did that work for you?

This is what I'd do. I posted this pic a while back.



My idea was to make the oil/air seperator ("catch can") from a short legth of PVC pipe with end caps and brass nipples screwed into it, filled with steel wool to act as the seperating medium. You can utilise the stock hard line to run across the top of the engine. You don't need to leave the check valve in place.

If you don't have an oil/air seperator you can tee the two lines together and run them to the TID in the same manner. But avoiding dumping blow-by oil into the intake is a good idea.

 

I knew that line had some thing to do with recirculating some thing into the intake duct, but i thought i was just reading the schematic wrong since one valve was going into the engine, and the other was going into the oil filler neck. i was like, "why the hell would you want to do that..." now that i read this thread...okay, so, i JUST got my rx running really well without the wb o2 and the air fuel controller. it idles great with the a/c on, and i can go at it as long as i want without fear of engine failure as retribution. However, the only thing i question is not necessarily your technique, but how does the steel wool act as a separating medium? is it just because the oil will just sit at the bottom of the catch-can, and the air is forced to the top through that nipple you put in the can due to the fact of volume restriction?? anyway, you say you can use the stock lines, and it looks like the line that goes to the tid SHOULD, for all intents and purposes, be at the top. so, this other question remains, how big of a catch-can should one expect to purchase?? yes, i plan on making it out of pvc, but, what are the approximate dimenions (assuming Diameter and height?) for the proposed can? nz, youve helped me before and youre the ****. also, i still owe you those intercooler piping pics which should be up tomorrow some time. i am just so proud of myself that i got my car running the BEST its run since ive owned it. just minor electrical glitches are all that remains. so, i am particularly proud. just wanted to let you forum members know that i appreciate your help immensely. if it werent for you, i would still be a bumbling fool about everything. now, i am just a bumbling fool with about 95% of what is going on with this mysterio of a car.

Ryan Shannon.

 

ok, so now that i *think* i understand the concept of this contraption, how much steel wool should i use? too much or not enough (meaning fill it half-way with the wool, or just pile it all up in there? should it be packed in tightly, or relatively loose)???? questions questions questions. Sorry for being a nuisance, but i very much appreciate your suggestions!

Ryan Shannon.

 

When the air and oil vapour pass through the steel wool the oil vapour hits it and sticks to it, forming much bigger drops that can't get pulled back into suspension. It then drips down to the bottom of the can.

Since I wrote that I read an article about a company that makes aftermarket catch cans, and refined my design after seeing how they do it.



The inlet is on the side and the outet connects to the central tube on top. If/when I do this I'm going to try copying this idea. Interestingly, these guys use oil-resistant foam in their seperators.

Look at aftermarket designs for clues. Rotaries don't have as much blow-by as piston engines, so they don't need a huge can. I'll probably use 4" pipe and make it ~6" long, which is how big the one in the pic is.

Fill it up!

 

I am still routed from the top oil filler nipple to the old charcoal canister with an overboard vent.
The original fuel tank vent is still connected to the canister also.

I like the above idea of the purge line to the TID.

I expected the canister to get saturated sooner, but after a year & 15,000 miles it's less than 1/2 full.
No engine oil leaks at all.

 

hey NZ thanks for the reply a long *** time ago For some reason I forgot about this thread. Looks like I'm going to be saving another one of your incredibly simple to read diagrams, man I love your diagrams, haha. The way you told me to run the vac lines first to the side of the engine worked perfect but with my bnr stage III I get a lot of smoke after I've ran it hard and then come to an idle. Once I do this the turbo starts blowing alot of smoke out of the back so it looks like I need vacuum to the upper and lower nipples just like you have in your diagram. Thanks again for the info. My car is going down for a rebuild pretty soon and I'll just hook it up this way while I'm at it. Again thanks a bunch!

 

Okay, i just want to know why theres a hollow central pipe in that redesigned catch can. I see the outlet hole that connects to the tid in the picture near the top of the can on the other side. The only thing i dont see are the inlets from the engine block/oil filler neck. so, i dare to ask, whats the problem with routing the line that goes from the oil filler neck and sticking it in the top to where it trickles into that central steel pipe with the holes in it, filling the larger cylinder with steel wool, then having the other line from the engine block itself (i am ***-U-ME-ING) that line just gives air pressure, and not any oil (if it does transport oil, cant you just tie the two lines together and have them both trickle into the central pole in the pic?) and make another plug in the exterior of the larger pipe to have that air circulate into the outlet hole on the other side of the pipe? am i just confusing myself?

Thanks in advance,
Ryan Shannon.

 

You are confusing yourself. You must've missed what I said. The inlet is on the side and the outet connects to the central tube on top. Here's a pic of the completed can.



The air/oil mix enters the through the side connection and passes through the foam, which seperates the oil from the air. The air passes into the central tube through the holes on the bottom and passes out through the filter at the top.

Since you're making this yourself, you can add another inlet to the side and put a hose connction at the top.

 

Okay, so, since i am TRYING to make this myself, you are saying i could just add an inlet bung in both sides of this canister, have the central tubes with holes near the bottom (why are there holes at the bottom and not top??? is it because the inlets are positioned in the upper area all ready? wouldnt the oil sink causing the air to not circulate as it properly should?). actually...now that i think about it and ask the questions to myself...i THINK (dare i say THINK) i know what is going on. i am going to take an educated guess here;

The inlet in that catch-can in the picture has a single inlet, the steel wool will collect whatever oil there is within the air/oil mixture. since the holes are on the other side of that inlet, the oil droplets will collect to that, before the air fully circulates throughout the catch-can, thusly finely separating the medium from each other. When that happens (within little time i am sure) the air naturally wants to escape as internal pressure increases, thusly going into the 3 holes bored into the central tube that sticks out of the top-center of the catch can (which is why there is a filter there...if i WERENT recirculating it....right?! i feel like a lost puppy, but i am trying dammnit!). so, let me conclude my psycho-babble. since i want to recirculate it (i have the line all ready in the intake right now anyway) then i just make two separate inlets, lets say right on top of eachother...then keep the central tube as is. keep it full with steel wool. say, "screw it" with the filter on top, and just run a return line from the catch-can to the intake.

is that at all REMOTELY close????? please say yes, even if it is a lie...well, not really, but i just want to see if i am a little dumb, or a whole lot of dumb.

Thanks in advance,
Ryan Shannon.

 

I think you've pretty much got it, well done.

I'd probably drill a few more holes in the central tube to improve flow and so as it fills up there;s still a path for the air. It would probably be a good idea to put a drain of some kind in the bottom like asome aftermarket ones have. I've even seen some with a clear tube running up the outside so you can see how much oil is in it.

Hmm, the more i think about this, the more motivated I get...