TrentO

I did something a little different. I built a square catch can out of aluminum which sits behind the filler neck and basically becomes the filler. It has an AN-16 fitting at the bottom and it goes straight into a friction fit AN-16 fitting into the filler opening in the block. The box is 7" wide, 6" high and 5" deep. I have a breather installed into a tube which opens right in the middle top of the catch can. I have yet to test it, but oil drains quickly into the engine when poured into the catch can. This is on an FC and I had to "customize" the intake elbow. I'll try to post some pictures at some point. A pic before the elbow and catch can are installed is at www.rxracing.com

-Trent

CrispyRX7

iTrader: (139)

I'm interested in seeing this Trent. Can you take a pic please?
TIA
Crispy

Asleep

Weather is warm, re-built the oil drain, no 45's but still AN-10. Re-did the oil supply retaining the oil restrictor. As long as I keep it below 19.5psi, no problems. Above that I have blow-by.

4CN Air

iTrader: (7)

Where would be a good place for us FD owners to tap?

It's too bad the passenger side rear position (unused oil drain) didn't work out. Is this because upon acceleration the oil sloshes to the back enough to cover the drain?

At least something has been found that definetly works, but It'd be nice if I didn't have to remove the front cover for the fix

SPICcnmGT

I haven't read this whole thread or kept up with it, but here is how I fixed my oil blow by/catch can problem, without using a catch can.

I took the filler neck off, at least the plastic part, and pretty much made a new one out of metal. Basically the same shape and everything except at the square part, the horizontal part between where you put the oil in and where it goes into the engine, I placed some baffles. ex. |/ \ / \ /| They are just metal plates so the air can still get though easily, but the oil has to change direction 4-5 times(left and right) before it can make it all the way through. Even if it makes it partially through it will drain back down on the straights. I've had this on my car for the past year and I have had no problems at all as well as no oil in my turbos/IC/piping. The only down side is it takes a little longer to fill it up with oil because it drains slowly.

BTW this idea basically came from a very knowledgable car guy who has been around cars/racing a very very long time, and actually made one for his RX-3 that he had on it for many years before selling it.

4CN Air

iTrader: (7)

my problem isn't so much the oil slosh (as I don't track my car yet), but I can't seem to vent pressure off quickly enough, which is causing oil leaks around my oil drain (single turbo) and possibly leaking inside the turbo (BB). I currently have two -6 lines running from the stock filler neck. I'll be modifying an aluminum oil cap to accept -10 or -12 line very soon. I'm holding off on the custom filler neck until I go with the JayTech intake setup .

I don't have a restrictor because Turbonetics does not recommned it, but I may go with a .06 one soon if the problem persists.

Asleep

I have not had done enough road racing for an oil slosh problem. Crispeed's comments were on the money (you have got to see his video of his near 700hp car!) The vent lines need to as big as possible. And, using a large or custom can seems to be the ticket too. Something I would like to try. If you can set it up to have the oil drain back or sump back into the engine that sounds ideal.

Running the restrictor for my GT40R made a difference. How much oil pressure are you seeing above 3500rpm? Tell Turbonetics about that and ask what maximum pressure their turbo likes best.

TobiasRX

Before reading alot from this thread(but not all), i thought my rpoblem would be solved from the rob robinette site about the PCV valve.

So i took everything apart and saw oil from the first turbo inlet but no oil from the small vaccuum line on the pipe, in wich i thought would be filled with oil, infact it was completely dry.

Am i missing something here? it's easy to miss something when reading all the difficult english words here

rexset

I find a hole in the OMP that I'm not using so , I gone conect a hose to it to install properly the oil cach can , as soon as I get it ready I will send you pics

I think that it gone look very nice and with a OEM look , and I can use the OEM hose conection to contec it to the oil cach can.

rexset

sorry but they R telephone pictures for the moment

4CN Air

iTrader: (7)

you're venting from where the OMP used to be? Did you take the front cover off and totally remove the shaft inside? The shaft is still in mine, i wonder if it would vent with the shaft in place?

rexset

There is a hole just at the side of the shaft that I conect the oil cach can. it is small but by my consern big enouth to take the oil gas out the oil pan.

I have another front cover where I notice that hole.

I attach a pic of it

4CN Air

iTrader: (7)

for those needing a large catch can, and it's made of super trick CF

https://www.rx7club.com/showthread.php?t=570054

DRAGON_PERFORMANCE

Sorry for the thread resurection.
But has anyone tried a single turbo oil return going into the rear oil return, and using the primary turbo return as a crankcase vent?
I would use the front plate, but dont want to take it off at the moment.

ptrhahn

iTrader: (9)

Honestly,
Have you guys ever really looked at the contents of the catch can? It's foamy, milky, mayonaise-y, fuel-contaminated crap. Even if you let it sit, it never returns to looking like the oil that you drain out of the pan—even used.

Are you sure you really want to recirculate it into the motor?

I just pour it out, and replace w/ fresh oil.

gracer7-rx7

iTrader: (16)

You make a very good point there. The stuff in the catch can is indeed nasty and does not in any way resemble oil. I certainly wouldn't want to mix it with my clean and expensive oil. Now that I'm running a larger 1 quart can, mine doesn't fill. Granted I'm not running R comps but...

Flynbryn

First off I'd like to say that I was battling this same problem with Turbo FC Track Car. after reading this thread I decided to go the OMP route. I removed the block off plate (shaft & gear already removed) drilled a hole in the block off plate that lined up with the hole the shaft went through and tapped and threaded a 3/8" pipe x -8 male flare adapter and ran a -8 line up to the upper portion of my catch can. Also plumbed into the upper portion is a -8 from the upper portion of the filler neck. According to the theory of this thread now both sides of the engine are vented. so right and left G forces are counteracted by each vent. Well the real test was at Willow Springs a week ago. Willow for those not familiar with it has three high G right handers (both over 100 mph) these were filling my catch can (that only vented from the filler) up after one 20 min session that is 1 qt of Mobil I (6 bux) !. After this new configuration I've done 20 track sessions 8 at Willow. and not one drop of Oil, Foam, or Milky Spooge (technical term). My third gen buddy vents from the rear turbo drain, you can do this but be careful not to run the hose too close to the downpipe. He just emptied his fire extinguisher from a burnt vent hose that was too close.
Problem Solved! Thanks everyone that contributed to this thread in my oppinion it should be sticky!

Dave McLaughlin

Very informative thread! I recently experienced the oil problem at VIR. Oil all over the plug wires and oil filler side of motor, not to mention, the drivers side under-belly of the car to oil on the rear bumper. Made for some greasy rear tires...I was able to get ahold of Fritz and he made me aware of this common problem. I removed the oil filler tube, installed 5/16" vaccume hose that was missing from an open metal tube under the oil filler tube to the bottom vent tube on the oil filler. I re-installed the oil filler tube, PCV hose, and new hose as mentioned. Now the car looks like a mosquito truck. In connecting that previously open fitting from the oil filler to that metal 5/16" pipe with a vaccume hose, I now have an a volcano. Did I screw up by connecting these two ports? I do have a catch can on the way and will configure my set-up as this thread suggests. The engine has good power and seems to run ok, but somethings wrong for sure. Haulp!!!

Hyper4mance2k

iTrader: (40)

Is there any where else besides teh OMP hole or the turbo drain to vent on the other side. I have a FB and the OMP hole is the size of a pin and I don't think it will allow enough air to flow through to properly vent. I fill up a catch can just autoXing.

BobfisH

My setup is as follows, ill let you know how it works soon! only had it on the nurburgring so far and oil slosh isnt such aproblem there (fast flowing corners rather than slow sharp ones)

I have a catch tank in the top left hand side of the engine bay with 3 fittings. Two on the top, one on the bottom. The bottom one goes into the LOWER hole in the filler neck (i have a customer filler neck with two horozontal breathers from the side rather than the stock one horozontal one vertical)

One of the ones on the top of the catch can goes to the upper breather in the filler, the other one goes to the elbow on the primary turbo intake (stock location for where the vertical fitting on the stock neck used to route to)

Idea being that with two connections from the catch tank from the filler, one from the bottom of the tank and one from the top, when you corner hard, the oil slosh can make its way along the pipe into the catch can from the top, but not through the bottom one (due to the gravity of the oil in the can stopping it coming in)

The line to the turbo keeps the whole system under vacuum the whole time, and the lower line from the catch tank gravity feeds oil back into the filler on the straights.

The can stayed about 1/3 to 1/2 full the whole time i was at the nurburgring, and im doing oulton park (a tighter circuit) tuesday. Ill let you know how it goes.

heres a photo of my engine bay so you can see where ive put stuff. The catch can could do with being higher to assist in the gravity feed aspect but the bonnet gets in the way (1/2 full catch can is about the level of the breather nipples, move catch can up, more will drain)

The catch can is in the very top left...

BobfisH

Based on RX-heavens setup i've thought of something that would probably work for a near stock FD.

Take a catch can with a breather on the top, 2 fittings in the top, one in the bottom - or 3 on top one on bottom and no breather.

Find somewhere to tap into the side of the engine (left side, opposite to oil filler, i have some plates ill look at for this) and tap a nipple or fitting into there.

Run the filler neck breather and the newly created nipple to the top of the catch can, run the other fitting on the top to the intake on the primary turbo and use the bottom one as a drain. if you have one with a breather on the top dont worry about the line to the primary turbo elbow.

I'm going to seriously look into doing this - i reckon you could probably get in there with a drill with the engine in place to make the other fitting, just have to remove the sump to get rid of the swarf.

I will let you all know how i get on, seems that doing this will fix the problem forever so much better than faffing around with different catch tank setups.

ptrhahn

iTrader: (9)

I've tried basically every catch can, baffle, turkey baster, mod, oil level trick, etc., and then some for my car, and here's what works the best.

I stopped trying to prevent the nasty stuff from leaving the filler neck in the first place, and instead choose to just let it out and make it easy to get rid of.

This is essentially what the GReddy can is, i.e.: a line from the filler neck or cap in, a can to catch the oil, and then a line out to a vacuum source (primary turbo inlet).

The problem with the GReddy was I would fill it up in one 20 minute session, and it's a total pain in the friggin' *** to remove from wherever you've mounted it, disassemble, and drain. Stupid design.

That's right, it's a bicycle water bottle and frame mount. Available anywhere, cheap, lots of styles/capacities... all I did was add the inlets w/ hardware store fittings. Drains in two seconds.

Problem solved.

RX-Heven

iTrader: (1)

That doesn't solve the problem at all except making it easier to drain. Have you tried venting the other side of the engine like I and a few others have?
If you have, you wouldn't have any oil to drain or worry about in the first place since the oil stays where it belongs...in the engine.

I still give you an A+ for creativity though

ptrhahn

iTrader: (9)

How does it not?

You could spend a HELL of a lot of time, money, and stomach acid (this thread proves it) worryng about the fact that the car pukes a little oil and trying to "fix" it, when it's in fact not really much of a problem so long as you're: 1.) allowing pressure to escape; 2.) not overflowing or allowing oil to get all over your engine bay or rear tires; 3.) not going through alot of hassle to drain/refill.

Maybe I'll get around to tapping the other side of the pan one day, but to be honest, i'm not real worried about it anymore, and per my post further up, I've SEEN the crap in that can, and I worry less because it's being evacuated.

RX-Heven

iTrader: (1)

The reason the crap in the catch can looks (and smells) the way it does is for the simple fact that the pressurized gases in the oil pan mix with the oil on their way out of the engine. Allowing the gases to vent cures that problem too. I found that out after my first oil change.