I'm worried about my friends 2jz, no shit.
 

No sorry this isn't exactly about a Miata. Just a quick question about something worrying me.

Some of you know I work on many different engines.
Also you know about my friends Turbo IS300 we just had to swap the 2jz-gte block into.
Well it's running and quite well. Fixed the boost controller two days ago so now he's at about 15psi to be safe. Also converted him to Rotella T6 goodness.
But I got worried with his catch can setup.
https://www.miataturbo.net/attachmen...ine=1392889224
As you see it's that little guy in the typical catch can location. He's running no drain/no level. I noticed today right after this picture that there was smoking coming out if it at idle. So I thought "Yo is your oil catch can full or something?" Well... it wasn't.. not a single drop..
Now from my knowledge, it's not suppose to seep out smoke correct? Unless you're head/valve train is burning something.
I suggested a leakdown test.

He's also to lazy to tap the oil pan for a drain again.

GE to GTE block also has a change in compression.
Also(probably the reason why the GE) block failed, he switched from some precision that blew up to fea's favorite BORGWARNER S366, boost spikes/overboost and pew.
Well he hasn't had it retuned. It's still running the 450hp @17psi or the precision turbo.
He watches the AFRs but that's really all he can do with his setup. It's fuel only haltec piggyback because the IS300 has VVT and people blow their motors messing with timing.
Which that all just seems... disastrous.
No?

Only time I've seen smoke come out of the catch can filter at idle was on the formula car after the alumni tuning it on the dyno toasted a ring.

Is it actual SMOKE, or is it steam/vapors?

I run the same sort of can on the MX6, and on cold starts at idle sometimes it'll throw vapors out. Smell it, and it smells like straight gas.

The crap i drain out of it is never oil-y. Just gross looking and smelling water consistency stuff.

my catch can emits vapor after a hard boosted run. If you smell it, it's SWEET and kind of smells like fuel/oil vapor. SMOKE on the other hand has a very harsh smell.

I was concerned about the smoke/vapor from my can and did some rigorous googling, most of the results i found said vapor out of the can is pretty normal when VTA.

I'll let others chime in :)

Yeah when I said smoke I meant smoke, like its smoke smoke, not vapor. Smells like oil.

I was asking OP, sorry.

I was just clarifying. When did you become canadian?

Sorry.

Sorry.

Umm I'll let you guys know here in a bit. I didn't think to smell it at the time.
Smoke=bad
Vapor=good/alright
It was after we attached the boost controller so the most boost the motor saw was 5-7psi(wastegate)
Which I'm sure he's boosting on his way tutu my place right now.
Hopefully it's not like the F1 toast for rings is the last we need.
"Now me and the mad scientist gotta rip apart the-block and replace the piston rings you fried."

It's probably fine, a little vapor never hurt anyone. IF it is vapor, make sure to add some kind of steel wool, or abrasive material for the vapor to condense on and drip down into the can. If that can is just VTA with nothing in it, i'm almost certain it's vapor you are seeing. Mine is setup the same way and vapor was noticable when the hood popped when the car was idling after a hard run. I have a similar catch can setup, and adding a bunch of steel wool in between the ports from the VC and the filter really helped with the vapor.

https://www.miataturbo.net/attachmen...ine=1392916289

I love seeing people add a catch can with a bit VTA filter on it...you know, because there isn't a reason OEMs pull vacuum on the crankcase...


A proper catch can will be mounted away from heat to allow the vapors to condense. They will also have a proper medium/baffle to encourage proper condensation of said vapors. Lastly, they should be routed back to the engine to pull vacuum (pre-turbo for turbo cars) on the crankcase. Good vacuum on the 'case is good for the engine and helps efficiently. Technically, you can replace the PCV and breather with (a) catch can(s) given they have a vacuum source and not a source that gets pressureized.

I've read dozens of catch can threads on this forum over the years. I've never been able to find a solid consensus on this though and the argument always goes back and forth. If you route it pre-turbo, your turbine inlet gets oily and oil vapors can cause detonation. If you VTA you don't get vacuum. Everyone thinks they know the best way to set it up, how would you recommend i route mine Dopple? Run the can on the dr side and pipe it back to the turbo pre inlet?

I guess it depends on racecar vs streetcar as well.

It's the scavenging argument.

In theory, it should see vacuum because it's better and stuff.

In practice, as long as your vents are sufficiently large, it doesn't matter.

There's more emissions when VTA, it's messier, and smells bad. This also plays a role in why OEMs don't do it.

Myself? I have a hard time finding a PCV that fits in my shit that will hold up to 30psi, so i just vent. In the race car, i don't have a vacuum source, so i just vent.

I have a VTA catch can and you can see it blowing lots of vapor/blowby/air whatever at 15-20 second mark.


I actually had to relocate mine because the "standard location" by the fuse box is right by the cabin air hole and it was stinking up the car a bit.

I agree with everything that Fireindc said - I also read tons of threads and its always the same shit. I feel like just saying fuck it and buying a vaccum pump.

Update, it was a sweet smell of oil vapers. No big deal. But vapors at idle just don't seem right
He's planning on running 600hp or whatever 30psi gives him. So I just didn't feel it was right.

The "Not another catch can thread" thread is always a good read. I thought there was a post where they found that the VTA had best flow from exhaust dumping, if I remember correctly. The only problem with pulling vacuum pre turbo is, now you get those escaped vapors through all that.

I have kept the PCV and put a typical VTA breather on the exhaust side. The vapors are messy, yes, spews like Soviet's on the dyno pulls I've seen as well. Ice been thinking of just running a hose to one of the ports I have on the FM piping(preturbo)

We'll see how good the catch can I'm working on works out. If it actually catches most of the oil its a huge winner since it doesnt have a major pressure drop across it at the mass flow rates that any non-blown up engine should be putting through the breather system. And I'll post everything needed to make one online since I probably cant just start making them, its kind of infringing on a couple existing patents. And by kind of infringing I mean blatantly rips off.

Stick it to the man!

This is a few days old, but just to clarify...

There is there is not much vacuum ahead of the throttle body, so pre turbo is not too useful. probably just get oil in the piping.

the rest of what you said is pretty spot on. Vacuum is good for the crankcase, pressure is bad. I think there is some discussion about stronger PCV valves to handle pressure from the IM, but that will require some searching. Dunno how well that will work with this engine, shouldn't be any different I guess.

The time you need vac in the crankcase the most is under boost, which is also when you'll be making the most vac between the turbo in the filter.