catch can
- Thread starter MiAde2d
- Start date
Pronto
Believe nothing you hear and half of what you see.
- Joined
- Dec 9, 2002
Good thread. Thanks.
A few question.
Is the PCV needed?
DO people run no PCV?
What does the PCV do exactly?
Is it necessary?
thanks
D
NY Twin Turbo
All the good stuff.....Times 2.
- Joined
- Dec 10, 2014
I know this could start a long drawn out thread of disagreement. But here goes anyway.
If you are not interested in keeping it looking stock, then get rid of the PCV valve ASAP.
Put a tube in its place and vent it to atmosphere. Or plug it. Or buy another drivers side valve cover and add another breather. Or buy a cheap electric vacuum pump.....or something. Just stop sucking that oily nasty dirty ass crap air into your intake.
That's my story and I'm sticking with it.
Pronto
Believe nothing you hear and half of what you see.
- Joined
- Dec 9, 2002
No, it's first job is to relieve the block of built up blowby and condensation. In the old days they basicly had a tube running out the block to the air. Later to reduce pollution, the devised the pcv to suck the fumes out of the block into the intake. There are literally hundreds of threads on the pcv, you can decide for yourself.
NY Twin Turbo
All the good stuff.....Times 2.
- Joined
- Dec 10, 2014
Sure you can.
It's nice to have a breather or 2 or even 3. We all know that letting positive pressure in the crankcase out is a good thing. It's even better to have a little vacuum help "pull' it out.
But I don't think pulling it into the intake is the way to do it. Besides, your emissions inspector would have to know these cars pretty damned good to notice a deleted PCV valve. Even if you wanted it to stay in place, you could plug the hose or fill the valve with epoxy or something. Because it doesn't effect what actually happens at the tail pipe.
All it is is a simple one-way check valve. It allows yucky misty oily air to enter the intake. But if it fails, it allows boost to enter the crankcase! This is even worse.
Some would say, it helps eliminate condensation in the motor and helps evacuate other contaminates. And this would be mostly correct if we were housewives who drove beaters for 5 years without changing the oil. But this isn't the case. I'm sure you change your oil twice a season. Even when it's not raced, I normally change mine 3 times a season.
I'm not saying the PCV valve is possessed by Satan (like the powermaster). Just that it's stupid.
- Joined
- Feb 18, 2006
Terrible misunderstanding when it comes to the pcv.
The pros outway the cons. A pcv is absolutely NOT stupid. People remove it and think that it made the engine run better or helped in some other way, It's just not so.
The pcv plays a key role in vacuuming moisture and contaminants out of the engine that would otherwise deposit itself in the oil.
The most ridiculous part is that the pcv closes shut under boost and deletes itself. It only works when in vacuum. So why anyone would remove it is beyond me.
Furthermore remove the pcv and get ready for crankcase emissions to fill the cabin and make your clothes smell like ass.
Personally I can't think of even 1 pro of deleting the pcv. It just makes no sense.
My $.02
The pros outway the cons. A pcv is absolutely NOT stupid. People remove it and think that it made the engine run better or helped in some other way, It's just not so.
The pcv plays a key role in vacuuming moisture and contaminants out of the engine that would otherwise deposit itself in the oil.
The most ridiculous part is that the pcv closes shut under boost and deletes itself. It only works when in vacuum. So why anyone would remove it is beyond me.
Furthermore remove the pcv and get ready for crankcase emissions to fill the cabin and make your clothes smell like ass.
Personally I can't think of even 1 pro of deleting the pcv. It just makes no sense.
My $.02
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- Joined
- Feb 18, 2006
NY Twin Turbo
All the good stuff.....Times 2.
- Joined
- Dec 10, 2014
. And there it is! I was waiting for that.Two very different opinions. So now it's up to you. Either way it won't change the world. Good luck.
Oh, by the way. Very nice set-up on everything as a whole, including the catch can install.
- Joined
- Feb 18, 2006
Develop an internal coolant leak and you will wish you had a pcv. That stupid little valve can save your motor.
This subject is terribly misunderstood. Most who delete the pcv have some theory of why they did it but the real problem is something entirely different.
Sorry to get off the op's subject. Hope the pics help.
Good luck
This subject is terribly misunderstood. Most who delete the pcv have some theory of why they did it but the real problem is something entirely different.
Sorry to get off the op's subject. Hope the pics help.
Good luck
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NY Twin Turbo
All the good stuff.....Times 2.
- Joined
- Dec 10, 2014
So to compromise...............................
I understand they draw quiet a bit of power, also I understand they may not pull enough vac, but why not an electric vacuum pump? If one can be found to perform adequately, that is.
- Joined
- Feb 18, 2006
You have a PM
- Joined
- Jun 18, 2001
What is there to compromise? The PCV system is extremely important. I had mine deleted and then started getting my oil analyzed. Even after two thousand miles, the oil was horribly contaminated. The lab even diagnosed it as a failed PCV system in the report! I hooked it back up and the next report looked like it came from a new car.
The issue with a vacuum pump is they're expensive. Sure, you can grab one from an old F-body, but they have to be plumbed in with a PCV, because the pump relies on the engine to provide most of the vacuum. The pump only kicks in high throttle. It's not rated to run continuously and will fail quickly if run so.
Now, you can run into problems with boost leaking past the PCV because it's a cheap valve. The solution is a better valve, not deletion of the circuit. I experimented a lot with mine and actually ended up with a two-circuit PCV system with two catch cans. One circuit feeds from the PCV hole in the intake through a catch can with a check valve to keep the boost out of the crankcase. This circuit needs to be maintained if you're running the stock ECU because without it, your BLMs get screwed up.
The second circuit feeds off the breathers. and draws through another catch can and into the MAF pipe between the MAF and the turbocharger, with another check valve to keep compressor surge from entering the crankcase. This setup has eliminated crankcase pressurization for me, as well as my rear main seepage. I also don't smell like a gas station after driving my car, and my oil stays REALLY clean. The catch cans are effective, too. I get a watery mix in the one on the PCV circuit, but the intake is staying clean and my oil level isn't changing.
NY Twin Turbo
All the good stuff.....Times 2.
- Joined
- Dec 10, 2014
OK, Generally speaking, I think I'm convinced.
I wrongly do tend to address some questions from forum members as if their set-ups were used similar to mine. Also, sometimes I believe most monitor and address their TR's maintenance as I do. This is obviously not the case.
As I have stated before, my experience only goes as far as owning one TR for 22 years. For me a vacuum pump would be a consideration due to available room and its limited use.
I would never recommend any component removal that can hurt any TR owners engine.
I removed my PCV valve years ago when it was a factory type set-up. I did not see any ill effects. I didn't have my oil tested, of course. But then again, since then, things have changed a bit for me. There are no provisions in my current set-up for a PCV valve.
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monteperformanc
Member
- Joined
- Jan 15, 2009
Where do you get these check valves for the breathers? I would assume they are pretty large?
- Joined
- Jun 18, 2001
Grainger!
http://www.grainger.com/product/GRA...b91439220d6a5378742ec08908eb2a02c&origin=prod
Get that, and two 5/8" hose barbs and you're rocking. I used a smaller one and 3/8" hose barbs for the stock PCV circuit. They're rated for water up to 500psi and 375 degrees F. As long as they're in the path after the catch can, they won't get gummed up with crap and stick. Boost cannot leak past these valves. Everything attached to the intake will launch through the hood and land in the next county before these fail.
As with everything, you should inspect them periodically to ensure they're working.
Another thing that isn't mentioned here is low RPM/idle fueling. The ECM expects to have a metered air leak after the MAF. it takes the MAF reading and adds the PCV air for the injecters to hit a desired A/F ratio.
By plugging it, you can risk being to fat at idle and low speed cruise.
...which oddly enough, can put unburned fuel into the oil where there's no PCV to suck it out.
Another tidbit is the assumption that our non-grannylike driving habits keep moisture boiled out. That's kinda sorta true... But while it's being steamed out, there's moisture in the oil.... Ever sat a cold beer down on a table and notice it gets covered in sweat?.. the inside of the engine block does that everyday too.
By plugging it, you can risk being to fat at idle and low speed cruise.
...which oddly enough, can put unburned fuel into the oil where there's no PCV to suck it out.
Another tidbit is the assumption that our non-grannylike driving habits keep moisture boiled out. That's kinda sorta true... But while it's being steamed out, there's moisture in the oil.... Ever sat a cold beer down on a table and notice it gets covered in sweat?.. the inside of the engine block does that everyday too.
- Joined
- Feb 18, 2006
I run a oil cat catch on the PCV circuit as well. The above picture is a new build. PCV catch coming soon on that.
I have had thoughts of running a 3rd line off the valve cover catch to the intake pipe to do what your doing. It's a great idea. Would love to see some pics of your set up.
