Crankcase ventilation

[DavidPHumes]

Hey guys,

I am having an issue with my car that I think is the result of insufficient crankcase ventilation (it's a 2.4L with a FP GT3582R).

My setup is as pictured:



Basically it's just 2 lines, one from the PCV and one from the valve cover to a vented catch can. I'm getting hardly any blow by (driven it 600 miles and only got a teaspoon in the can) but have a lot of pressure in the crank case.

I had to put a spring on my dipstick to prevent it from shooting out (a common issue, I know) and now oil is coming out of the oil fill cap, dripping onto the valve cover and eventually burning off. The result is that I'm burning a noticeable amount of oil from there and not only does it smell, but it worries me that I will run it low (a long shot, I know).

Could my issue be insufficient ventilation? Would -10AN to a catch can be beneficial? What have you all done on a setup like mine? I'm flowing 58lb/min at WOT right now.

I'm very green to DSMs but have a little understanding when it comes to PCV systems.

Thanks.

[DavidPHumes]

I should mention: although I don't have the normal symptoms (overheating, water in the oil, loss of water, smoke, etc.) I have a gut feeling that my HG is bad (I have had a rubber cap blow off of my lower tstat housing twice but once was because it was dry rotted and the other was because it was a 2 piece cap so it's tough to say why it happened). Can this cause excessive pressure? Compression is 165 across the board cold, 150 warm on all 4.

[Kracka]

Set it up like stock; breather to the intake pipe and PCV to the intake manifold.

[DavidPHumes]

Originally Posted by Kracka

Set it up like stock; breather to the intake pipe and PCV to the intake manifold.

If that's the answer then why does everyone "over complicate" things and go with the setup I have (albeit usually a "bigger" system overall)? I'm not trying to say you're wrong, just want to know the WHY.

BTW my plugs looked good so I don't *think* excessive blow-by is the culprit either.

[Kracka]

Everyone thinks they can out-engineer the engineers. From my experience, catch-cans seem to create more problems than they solve. Setting it up like stock always puts a suction on either the crankcase vent or PCV vent which is better than just allowing excessive pressure build up to escape on it's own. If that solution doesn't work, then do the same, only with larger lines. Having a little oil vapor/mist in your intake charge is actually a good thing since it helps keep the BOV and wastegate actuator internals lubricated.

[evotuner]

^interesting take, i may have to try this out myself

[C3L1CA]

I had the same issue until I went to a -10an setup, cured my problem of shooting the dipstick out.



You drive a heavily modified dsm with a 2.4 and a gt35 that you plan on daily driving. A heavily modified dsm can make for a good daily, BUT you need to plan on checking things over a lot more often (like your oil level) than you would on a stock civic for example.

I had to keep an eye on my catch can and empty it every once in a while. I also didn't have any baffles in my valve cover either so that probably helped fill the catch can up even faster.

[turbotalon1g]

Pick up a JCS automation/calan catch can.
Use 2 -10AN lines from VC to can then a single -10 or -12AN to intake, his cans will not leave anything in your intake, I have one and love it.

[Halon]

This subject has been beaten to death here a few times. Check out some of the older threads for insight.

FWIW, I agree with the idea of keeping the stock pathway. Although I would consider putting sealed catchcan's in line with them, as well as consider increasing the line size of the one going to the inlet pipe.

[Dizmm]

for a stock-ish car, run the stock setup.

if your running 400+whp, then its time to create some bigger ports and allow the motor to breathe.

[Goat Blower]

What happened to Kracka vents?

[Shane@DBPerformance]

It you have normal ARP head studs and your making decent power at all, then the head is probably lifting.

[Kracka]

Originally Posted by Goat Blower

What happened to Kracka vents?

MAP sells them.

[s1ngletracker]

If you want suction in your crankcase, do a slash cut in your exhaust, with a check valve to keep exhaust surges from pushing back into your crankcase. Slash cuts will actually increase in vacuum as boost/load increases, as opposed to intake manifold which will close the PCV valve and give you none. The intake tube port has a similar effect (though not as much) but also will spray discharge into your intake.

You don't need crankcase vapors to lubricate your wastegate actuator and BOV - a lot of the time your crankcase discharges are steamy (water vapor) nasty fluid anyway. Plus your turbo willl almost always spray a finite amount of oil there anyway.

[Dizmm]

Originally Posted by s1ngletracker

I

You don't need crankcase vapors to lubricate your wastegate actuator and BOV - a lot of the time your crankcase discharges are steamy (water vapor) nasty fluid anyway. Plus your turbo willl almost always spray a finite amount of oil there anyway.

this is mostly why i chose to vent my catch can rather than route it back into the intake pipe. not much vacuum is created anyways. Big thread on DSMtuners and EvoM about this.

What was in my catch can (mostly water):


(this was my testing valve cover) I did 2 large NTP ports on the end, used a tap, some $2 NTP fittings, and routed them to my catch can. I used to get some blow by smoke and now i get none.

[turbotalon1g]

If you use a real catch can, you will have no issues with anything getting back into the intake.

David, search dsmtuners for calan and his catch can and I promise you will be happy with the results. Hell I'm buying another one soon.

[blageo23]

I have both the PCV and vent open. No catch can, not hooked up to anything, just sitting there. I've had no issue with dipstick blowing out and I don't get any oil out of either vent. Maybe a drop or two after a while. I realize it's not the right way to do it but it hasn't been an issue at all.

[Dizmm]

Originally Posted by turbotalon1g

If you use a real catch can, you will have no issues with anything getting back into the intake.

David, search dsmtuners for calan and his catch can and I promise you will be happy with the results. Hell I'm buying another one soon.

the other problem you have with doing large crankcase ports routed to a catch can, then routed to the intake, is you will significantly alter the metered are by the MAF. If you are running the stock size port from the valve cover, you can get away with it.

[Tachyon]

Originally Posted by s1ngletracker

If you want suction in your crankcase, do a slash cut in your exhaust, with a check valve to keep exhaust surges from pushing back into your crankcase. Slash cuts will actually increase in vacuum as boost/load increases

A couple years ago I was interested in this idea. It appeared to gain popularity the Civic and Supra crowd a while back and did net some gains on the dyno. I think I might finally give this a try since my DSM is my experimental tech donkey.

I am thinking 2x -8 fittings and lines within an inline baffle box system, then 2 beefy check valves into opposing slash cut tubes. IIRC, the main issue people were having at the time were the valves getting clogged with coked oil. I am thinking the baffle box could prevent this if done correctly.

Paul, do you have any experience with this in a quasi-race environment?

[s1ngletracker]

Originally Posted by Dizmm

the other problem you have with doing large crankcase ports routed to a catch can, then routed to the intake, is you will significantly alter the metered are by the MAF. If you are running the stock size port from the valve cover, you can get away with it.

Can you explain this more? Hasn't that air been metered?

Originally Posted by Tachyon

A couple years ago I was interested in this idea. It appeared to gain popularity the Civic and Supra crowd a while back and did net some gains on the dyno. I think I might finally give this a try since my DSM is my experimental tech donkey.

I am thinking 2x -8 fittings and lines within an inline baffle box system, then 2 beefy check valves into opposing slash cut tubes. IIRC, the main issue people were having at the time were the valves getting clogged with coked oil. I am thinking the baffle box could prevent this if done correctly.

Paul, do you have any experience with this in a quasi-race environment?

Yeah, I have a slash cut on the chumpcar. This weekend will be the first time it will be run in a race. We had an awful problem with a rapid filling catch can last year, I even posted on here about it, and I got little or no help. I'm much more confident in our new setup, it also has a drainback to go back into the block so we don't have to waste time at pit stops draining it. On a street car draining it is acceptable, on a race car where you need to have ~4 minute pit stops, you want as little to do as possible.

I'll let you know how it goes! In theory it should be ok, but I have some concerns about it, namely the hose I have connected to the slash cut getting too hot.