Yeah, that's on my short list. I have Radium's giant catch can on the intake side, barely catches anything. I'd like to swap that out for two of the smaller ones, one for intake side, one for exhaust side. Just need to get them purchased.

 

I think I'm going to try that AOS for the hot side. I recently rebuilt and have been having my catch can fill up like crazy on track. Previous motor build was basically dry after 3 months. Haven't changed the breather system at all. Stepped the oil drain from kinked -10 AN to new bung and -12 AN.

Repurposing the old 3 bar MAP sensor to measure crankcase pressure and will hopefully have some data tonight once it's wired in

 

So I am in the same boat in terms of oil pooling in the compressor housing and intake tubes. I do already have -10 an lines from the valve cover to a VTA catch can. If I am understanding this correctly, you used this setup, at least for the turbo side, to help? if so, should I keep my PCV side vented to atmosphere via the breather can used in my current setup and run the turbo side the way the picture is showing to see if that helps?

 

Yes, that's what I did. Again, very preliminary results, only ~40 miles and a dozen or so dyno pulls. Just spent all weekend at Sonoma, didn't get a chance to put any additional miles on it.

 

Someone asked for a picture of my current setup, here it is. Exhaust side will eventually get a small radium catch can. The new ones have built in check valves, I'll probably end using one on each side.

 

Wow interesting, so relieving crankcase pressure solved your problem with oil getting past the seals.. As someone else said maybe the EFR's don't like any crankcase pressure.

Does that crankcase line from the valve cover to intake pipe have an AOS at all? My concern would be over time it would pull vapors into the intake tract from the crankcase but if it's working that's awesome. I've had discussions with folks where people swear the crankcase needs vacuum on it vs just letting it vent to atmosphere but depending on the car and setup (like on a track car), I'm always worried about oil getting into the intake tract from the crankcase. I know another old school way is a slash cut tube in the exhaust pipe to the crankcase but I'm sure that'd get smelly/messy.

 

As I've said multiple times, my plan is to add a catch can eventually. Yes, it could suck in oil, but nothing so far, both raw oil from turbine seals, or oil vapor from crankcase.

 

I’m fairly late to this conversation but I have been following it while trying to rack my brains around my EFR oil issues. I hope that I can add little to someone’s else’s journey!

Quick back story back in 2020 I restored a 1998 NB with the vision of dropping most off my boosted set up from my previous NBFL. Upgrading to a forged engine and EFR setup.

Pretty much since day one after the initial break in and dyno I started to notice oil in the air filter also intercooler/pipework.

First fix, I opened up the drain full bore from the turbo outlet to sump with a continuous fall.

Second fix, drilled out the rocker cover on the hot side similar to how SPS motorsport advise in higher HP applications and fitted 2x 3/4” bore breathers to atmosphere. The cold side is also vented to atmosphere AN8.

Third fix, fitted a Turbosmart V1 OPR.

Fourth fix, utilised a breather on the block i pre drilled during my second rebuild. AN8 hose line to a catch can vented atmosphere.

Fifth fix, fitted an additional oil restrictor (1.8mm).

All of these mods helped the issue but none of them have completely solved it.

I am pretty sure the engine isn’t creating excessive blow by I have done a leak down test in the past along with compression tests. I even rebuilt the engine again (rings, shells, machine shop rehoned, another crank all balanced and new boundary oil pump) after a bad set of injectors from the initial build diluted the fuel somewhat coupled with the extra oil from the BW it wasn’t 💯 so couldn’t rule it out. Still running well but I took the plunge again 😂 I upgraded to ID1050s and replaced the CHRA for the ally version. Again after this it was run in and dynoed with a professional made 352bp at
15psi but the problem persisted!

On reflection;
The greatest fix being the oil restrictor (which I tried to avoid all along as per BW manual)
Nearly stopped the oil leakage but over time it has reappeared slightly and Im still not happy to hit the track!







@curly I am relieved for you to see your problems have ceased! I am going to try a similar solution just deciding whether to attach the block breather to inlet filter via the catch can. Or bung that and use the hot side via catch can.

I really hope this solves it as this car has been a pain in the **** compared to the first which was beaten hard for 5 years. The original engine still sits there taunting me 🤣

 

Very clean engine bay. My thought is while 0 crankcase pressure is good, crankcase vacuum is better. In order to create that vacuum, you'll have to plug all but two of your vents. Under boost, my PVC side is check valved closed.

 

If it's of any value, I have a "catch can" of sorts between my valve cover and turbo intake fitting and have never accumulated much of anything in it.
The stainless mesh medium is even mostly dry.
There are some details in post #103 in my build thread. (from 2016... what happened to the years?)

 

So...apparently this isn't fixed. Drove with a co-worker to the reunion at Sonoma, total of about 1300 street miles, plus I did all 5 B sessions on Saturday. Had a blast, here's a picture before I get into the oiling.



I largely had no idea what I was doing, but got down to a 2:00 with a theoretical best of 1:56, Aim users can roll their eyes now. That's my coworker in the back, really cool to get a shot of both of us together on track!

On to the oil. I've since changed to Turbosmart's V2 pressure regulator, which eliminates the return line. I also changed my single competition style Radium catch can to two of their new fluid lock models, pictured below. Sorry for the mess, I already started removing some things. -10 fitting welded to the exhaust side of the valve cover, then back to the filter pipe. This catch can was completely dry after the trip. -6 welded to the intake side of the valve cover, through a 3/8 check valve, into the catch can, then a Radium PCV valve fitting, then back to the stock intake manifold port. This catch can had a couple table spoons of oil in it. After the entire trip and track day, I was maybe 1/4 low on oil.

Coworker behind me said my car would smoke only on decel, barely on the way down, and was more consistent on the way home.

At this point I'm considering changing the intake side of the valve cover to VTA and capping the intake manifold, to see if my oil on decel issue goes away. Although I'll likely take another year to match the mileage I did in 3 days this past weekend.

However I'm still concerned about the small amount of oil I see in the charge pipe, I'll have to disassemble some more and see how much has accumulated at the bottom of the pipe. I've already returned my new 6758 for a small restocking fee, but this may cause me to buy it back!



Couple more pics of the oil

 

Please keep us updated on any setup changes! I am in the process of trying to figure this out as well. Such a frustrating issue. My drain line is a -12AN nearly straight down and it still occurs. Not sure why others running EFRs are fine but I went from a 6258 to a 6758 and a new (used motor) so i am not sure what to look for anymore.

 

So far I've disconnected the intake manifold from the old PCV site and made it VTA. But it's 40s and raining here, so not much driving. I'll report back when I get some drive time on it.

After my previous post, I disconnected and inspected all of the charge piping, and there was hardly any on the turbo side, it was all just dripping down from the throttle body and collecting in a low spot below.

 

EFRs are very finicky about drain restrictions, inlet oil pressure, and crankcase pressure. Going VTA is always the right answer with a turbo, regardless of brand.

 

My hope was it would pull the crank case into vacuum in overrun, but looks like it's somehow pulling oil past the catch can scrubbers.

 

Significantly increasing the size of the ports and lines slowed the flow of the gases enough in my case to stop carrying oil vapor out of the engine. Simply slowing down the flow by increasing the diameter allows the oil droplets to fall out of suspension.

 

Any new updates Curly?

 

Since Miata Reunion, I've put 50 miles on it, 51 to be exact, so not enough for any concrete evidence. The PVC side is now VTA, but I'll drive it for a few hundred more miles before making any judgement. At the rate I drive it, that's mid-Julyish. Including last weekend, I'm traveling 12 out of the 20 weekends until then, so we'll see how much progress happens.

 

Just read through this thread. Super helpful thanks for posting updates. I'm sorry you're going through this ****. Since getting back from the tuner I now have this exact same issue. Nothing has changed physically on the mechanical side other than a new throttle body actuator/DBW setup. So pun intended I'm baffled. I'll try some of your mods and upgrade the tiny catch can on there as it sits.

 

Yeah I was going to link this thread in your build thread, but hadn't gotten around to it. The EFRs definitely seem to be sensitive to oiling system changes, some more than others, but typically it's a symptom of a larger problem.

In my case, I've driven it a few more times and it's now smoking really bad, even at idle. Previously it only seemed to be when I got back on the throttle after a period of engine braking. Was on my way home, sitting at a stop light, and looked behind to see a big cloud of blue smoke. So engines coming out, torn down, and hopefully I find something obvious. Compression and leak down tests were inconclusive, 155-165 comp, not in this order, but I had 2, 4, 6, and 8% leak down. Cyl 3 was the 155psi/8% leak down, so I guess I'll start there. Boroscope showed some scratches along the bore, 84.5 wisecos might be in my future...