Crankcase ventilation

[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]

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]

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):
http://i508.photobucket.com/albums/s330/Dizmm/IMG_4635.jpg

(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.
http://blog.365racing.net/wp-content/uploads/2012/04/IMG_4750.jpg
http://blog.365racing.net/wp-content/uploads/2012/04/IMG_4738.jpg

[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]

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]

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]

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?

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.