So I am thinking about tapping in to my catch can and putting a return line to the oil pan. The lingenfelter vetts do this all the time. I also am going to put a check value on the pvc value. what do you guys think?
BAD IDEA. If you saw the nasty crap that came out of a catch can, you'd understand why you DON'T want to put that back into your oil system. A check valVe on the PCV is a good idea. Don't know much about check valUes.
I dont think what comes out of the catch can I would want to put back into my oil pan just not worth all that work just keep up your oil change intervals-LOL
No need to reinvent the wheel bro.Like they said empty that crap out of there. The GM's and the chryslers are to different animals//
I'd have to disagree. The oil that comes out of my catch can looks just fine. Why would you think the vaporized/atomized oils caught in a catch can would be much different from the rest of the oil in the pan? The idea of the pcv system is to burn the *gasses* that come off the oil and the blow by from the cylinders. Not the liquid vapors that happen to go through there as well. Now, if you put a return line back to the pan you'd still need a valve in order to maintain the vacuum and have it suck from the right place. PCV valves are one way valves and they regulate the max flow.
First off I dont think the oil in the catch can is that bad, I had to actually think about this a sec, its just blow by oil. Second I would have to agree with Dave, the problems your going to encounter trying to keep the vacuum with check valves that really arent made to do what your asking it to do in this application will wind up being a bigger headache then just draining the catch can. IMHO
Well I disagree with you guys diagree'ing..lol For one thing i have seen time and time again is condensation in catch cans,obviously that will depend on climate etc etc, and when this happens it looks like a milk shake in there.I wouldnt really want that to go back into my engine.I have also noticed from time to time a gritty substance in my catch can.Not sure what it is but it happens ..Just my 0.2
lol verdict is my tuner already did it so we will see. Everytime I have changed it the oil looks fine. Never any grit or "milky shit" just looks like oil. I think my big problem is ging to be F/I with the catch can we will see I will also keep you guys informed
Condensation I could see. Don't know if it would be enough to cause a problem with 3K oil changes. I live in a desert so I've never seen any in mine. The stuff that gets through the pcv valve and up that hose is vapors and some atomized oil. Basically it's sort of the distilled version of what's in the pan. If you've got grit up in the catch can I'd say you've got bigger problems in the pan.
Hmmm, let's think about this. Manifold vacuum sucks air/vapors/whatever from the crank case through the PCV valve. Fresh air comes in the other side of the crankcase through the breather. The PCV valve is a one-way valve (and also regulates flow I think?). No idea if you get that much vacuum or not. I think (maybe even without F/I) you can get a momentary reverse pressure wave when you snap the throttle from closed (max vacuum) to open? So let's say you run a drain tube from the bottom of the catch can to the pan. 1) hopefully it goes into the pan above the oil level? Otherwise I suppose you might be sucking liquid oil up the drain tube into the catch can (and then the manifold?). That would be bad. In fact it would have to be far enough above the oil level (or some other means) to account for the oil in the pan running over to one side during lateral maneuvers -- like doing a high speed clover leaf... 2) If you were to get a reverse pressure then you're going to get a "burp" out of the PCV system intake breather. Probably not so bad. I think it happens occassionally anyway. 3) When you have a vacuum on the "out" side of the catch can where is it going to suck "in" from? If you're sucking in from the drain hose then --a) it's not coming into the catch can as designed. Probably would still work OK. --b) depending on the velocity and drain tube it might not be so conducive to draining oil down the tube when there's air getting sucked up the tube. I think maybe you'd want a one-way valve on the drain tube as well. 4) You may have to remove it or put a manual valve on it when you get a blower. I suppose the check valve you're going to put between the manifold and the catch can would take care of that so maybe not a problem there either. I think you need something like those automatic water purge valves that they got on trucks with air brakes. Of course you'd need some air pressure or a plunger when it activates. You could tap into the boost from your blower... Every few days AND when you've got boost it could activate the valve for a second or so and just blast everything down into the crankcase
Thanks bill nye. Yea I trust my guy he knows what he is doing. And if it all goes to hell it waas his idea and he will fix it.
Haha, just thinking about it. Even if it fails I think the worst case is that you burn a little oil through the manifold. The only thing I'd check on is where it returns into the pan. Some tuners might not think about road course issues.
Dave, I'll admit I didn't read your whole post........kinda tired right now. Maybe you covered this or maybe I mis read something. But you guys can argue the contents of the canister all day, mine looks great, but I've seen some really bad stuff before in them. But here's the deal: PCV...Positive Crankcase Valve. Do you know what that means John. That means that blow by is released by the PCV valve. All modern systems recirculate those vapors (and contents) into the intake system to be burned off in the combustion proccess. Now, if your relieving pressure by putting it right back from where it came......WTF are ya thinking. Like I said, maybe I missed a solution to this and if I did, I appologize.
I dunno Cam. It's not so much "released" by the PCV valve but sucked out the PCV valve with the vacuum from the manifold. That's still going to happen. If there is ever positive pressure in the crankcase it's goin to vent through both the PCV valve and the intake side. So all the gasses should still get drawn into the manifold. It's just the liquid that would (might) gravity feed back to the pan.
I'll empty my catch can tomorrow and take some pics for everyone. That should end this debate/thread.
To get in my 2 cents And to add to the same thing with a ittle more info.. The PCV (Positive Crankcase Ventilation) valve is not electronically controlled but is a pressure sensitive relief that relieves "crankcase over-pressure" (Ventilation) of "gases". (These partially combustible "gases" are returned to the intake by a rubber tube from the PCV to the intake) to be reburned. It is more of an "emmisions thing" to "re-burn" the spent "gases" from the crankcase.) The "crankcase pressure" is mostly formed from the "gases" that get past the rings (blow-by) during the compression and combustion strokes of the engine (and the presure formed by piston downstroke). It is also fed from the "fresh air" that enters the engine from the tube that connects from the intake tube on your air intake system to the head (near the oil fill tube). The PCV valve relieves this increased pressure. However there is a lot of oil flyig around in the crankcase, and on the way out these "gases" pick up the oil vapor and carry it thru the PCV valve as it relieves the crankcase "over-pressure". The "Catch Can" seperates most of the oil from the "gases" so the oil is not carried into the intake. AMW made one of the first catch cans for Vettes (mentioned earlier in this thread) and then McKinney got into the act. These guys make one of the best designs no doubt. There is WAY more engineering in the AMW and McKinney units which is why they cost more. You have to also think about the oil in the can "sloshing" or rising up he side of the can during hard turns (thlnk g-froce) Side Note.... At one time befor PCV a hose actually did just go from thetop of block thru a tube to under the car. Befor that seals were made to withstand the pressure. The complete story.. http://en.wikipedia.org/wiki/PCV_valve ..
well the car started up and idled for abit I would think the oil would be drawn in while its at peak vac.(idle) well after we shut it down the can was bone dry. Not saying its working but who knows. Time will tell, If it doesnt work what do I need a new oil pan and catch can bottem piece right?
