bye bye pcv any negatives to it???
- Thread starter EvanD
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If you are talking about your E36 M3, it does not have an electric pump that evacuates the crankcase. It has a cyclone separator.
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If you're going to run renegade, install one or two of these.
Make sure you retain a vent. It can pull enough of a vacuum to suck in seals. They used to be OEM GM after Grumpy Jenkins developed them for racing.
Make sure you retain a vent. It can pull enough of a vacuum to suck in seals. They used to be OEM GM after Grumpy Jenkins developed them for racing.
Looks like that's a real installation. Very neat. I'm surprised the hose doesn't burn up.
Originally Posted By: mechtech2
Oil, and therefore engine life, is lessened.
Oil leaks from pressure are ensured to happen!
But the PVC is a POSITIVE system. It allows the engine to make more power, for a bunch of reasons. Some guys use a dedicated electric pump to vacuum the crankcase for more HP at high loads and RPMs.
For much less trouble than filling the holes in the valve covers, you can have a working PCV system.
I can't believe that anyone would actually negate the PCV system.
Even a 'road draft ' system is better than nothing.
+1
Oil, and therefore engine life, is lessened.
Oil leaks from pressure are ensured to happen!
But the PVC is a POSITIVE system. It allows the engine to make more power, for a bunch of reasons. Some guys use a dedicated electric pump to vacuum the crankcase for more HP at high loads and RPMs.
For much less trouble than filling the holes in the valve covers, you can have a working PCV system.
I can't believe that anyone would actually negate the PCV system.
Even a 'road draft ' system is better than nothing.
+1
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Originally Posted By: AuthorEditor
Looks like that's a real installation. Very neat. I'm surprised the hose doesn't burn up.
While the engine is running its got a continuous cooling flow from the crankcase. Those hoses survive good enough. I imagine the elements would harden the outer surface of the hose. The check valve is only there for potential backfires. Normally this would be threaded at the exhaust manifold.
Looks like that's a real installation. Very neat. I'm surprised the hose doesn't burn up.
While the engine is running its got a continuous cooling flow from the crankcase. Those hoses survive good enough. I imagine the elements would harden the outer surface of the hose. The check valve is only there for potential backfires. Normally this would be threaded at the exhaust manifold.
I see alot of the same answers. With the PCV in place im sure you are 100x more prone to leaks oil. Didnt we see an audi RS4 with a UOA that was venting?
Take my Jeep 4.0. The PCV valve is just a fitting on the VC with a pin hole connected to the IM. How is that going to put a negative vacuum on the entire engine? Not only will it not keep up with displacement of the pistons, it will not suffice to the blow by, thus the flow reverses and VENTS to the airbox at anything above minimal throttle. Now that its venting, im only effectivly venting via 1 port. I doubt the vacuum in the IM is strong enough to pull from the crankcase with the throttle butterfly open >10% through a small hole like that.
Take my 240sx. typical PCV setup. However the fresh air inlet on the intake arm is restricted to put negative pressure inside the crankcase during vacuum. Once I add blowby to the mix, im just venting vapors out every outlet.
So now the only time vacuum will pull the vapors is when im at a stop, or decelerating. During acceleration Im not really circulating much. Now the PCV valve has suddenly become useless and a restriction. If I remove the restrictions, I have a vacuum leak, or I dont pull any vacuum, I just move air and the system becomes useless.
Or I just install 5/8th fittings and lines and vent....let the contaminants burn off at 212*f, which clearly seems like they make an escape according to my catch cans and hoses.
Take my Jeep 4.0. The PCV valve is just a fitting on the VC with a pin hole connected to the IM. How is that going to put a negative vacuum on the entire engine? Not only will it not keep up with displacement of the pistons, it will not suffice to the blow by, thus the flow reverses and VENTS to the airbox at anything above minimal throttle. Now that its venting, im only effectivly venting via 1 port. I doubt the vacuum in the IM is strong enough to pull from the crankcase with the throttle butterfly open >10% through a small hole like that.
Take my 240sx. typical PCV setup. However the fresh air inlet on the intake arm is restricted to put negative pressure inside the crankcase during vacuum. Once I add blowby to the mix, im just venting vapors out every outlet.
So now the only time vacuum will pull the vapors is when im at a stop, or decelerating. During acceleration Im not really circulating much. Now the PCV valve has suddenly become useless and a restriction. If I remove the restrictions, I have a vacuum leak, or I dont pull any vacuum, I just move air and the system becomes useless.
Or I just install 5/8th fittings and lines and vent....let the contaminants burn off at 212*f, which clearly seems like they make an escape according to my catch cans and hoses.
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Well I am still thinking old school breathers are the way to go in my case.
Very disappointed in the number of people who post without reading or maybe comprehending what others have posted.
Very disappointed in the number of people who post without reading or maybe comprehending what others have posted.
Originally Posted By: MrHorspwer
Quote:
Also, positive crankcase pressure reduces efficiency.
Venting to atmo is certainly not the worst thing you can do, but it means you don't have the benefit of intake vacuum to help remove vapors from the crankcase.
PCV goes in front of the throttle plate, not behind it. No intake manifold vacuum is applied to the crankcase. If you were to port intake manifold vacuum to the crankcase, it would create, in effect, a giant vaccum leak.
Unless you have a crankcase vaccum pump, all crankcases have positive pressure.
That's incorrect - for most engines. It is a giant, metered, anticipated, vacuum leak
Soory i just saw you realised your error. I dont understand how fancy rocker covers and MSD coils will add powee over stock well engineered ignition system. Now the dist on my old 4.3V6 - nasty bad.
Quote:
Also, positive crankcase pressure reduces efficiency.
Venting to atmo is certainly not the worst thing you can do, but it means you don't have the benefit of intake vacuum to help remove vapors from the crankcase.
PCV goes in front of the throttle plate, not behind it. No intake manifold vacuum is applied to the crankcase. If you were to port intake manifold vacuum to the crankcase, it would create, in effect, a giant vaccum leak.
Unless you have a crankcase vaccum pump, all crankcases have positive pressure.
That's incorrect - for most engines. It is a giant, metered, anticipated, vacuum leak
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Originally Posted By: MrHorspwer
PCV goes in front of the throttle plate, not behind it. No intake manifold vacuum is applied to the crankcase. If you were to port intake manifold vacuum to the crankcase, it would create, in effect, a giant vaccum leak.
Unless you have a crankcase vaccum pump, all crankcases have positive pressure.
Bzzt.
The PCV valve goes to the intake manifold. The valve itself (or orifice in the case of engines like the Jeep 4.0) limits the volume flow and prevents your "giant vacuum leak." The PCV *MAKE UP* air is usually tapped off of the intake plumbing above the throttle valve.
PCV goes in front of the throttle plate, not behind it. No intake manifold vacuum is applied to the crankcase. If you were to port intake manifold vacuum to the crankcase, it would create, in effect, a giant vaccum leak.
Unless you have a crankcase vaccum pump, all crankcases have positive pressure.
Bzzt.
The PCV valve goes to the intake manifold. The valve itself (or orifice in the case of engines like the Jeep 4.0) limits the volume flow and prevents your "giant vacuum leak." The PCV *MAKE UP* air is usually tapped off of the intake plumbing above the throttle valve.
Personally, I've been trying to figure out a way to *install* a PCV system on my old tractor. I don't see any downside in keeping the crankcase evacuated.
The rubber will not burn up provided the check valve does not fail. On the old aspirator systems, the check valve would fail and make the air filter case really hot to the point of blistering the paint off. Louder under the hood was a telltale sign.
As to the PVC removal, PVC's can be beneficial to engines in many ways.
As to the PVC removal, PVC's can be beneficial to engines in many ways.
I'll just say what I did and why I did it and the effects it had and leave all the other [censored] out.
I run a breather on each valve cover.
Primary reason is to vent crankcase gasses under WOT. The stock system had trouble keeping up once I nearly tripled the factory hp.
Secondary is to keep oil vapors from coating the intercooler. The fresh air side went in pre-turbo which reverse flowed under WOT. After a bunch of miles the intercooler gets coated with oil and loses it's efficiency.
And third, the PCV valve had to hold back 28+psi of intake pressure. I can only imagine how much oil it would blow out of the seals and breathers if the valve failed.
With regular rings I had a problem with the breathers becoming saturated with oil and occasionally dripping on the headers. Once I went with Total Seal gapless, the breathers stay completely dry. One solution I used while using regular rings was breathers with a 5/8" hose barb that routed gasses under the car.
I use a very short OCI partially due to not having a PCV system. I compromised idle and part throttle crankcase flow to keep it from pressuring up at full throttle. Honestly, I could probably use the stock PCV system with the gapless rings but I'm not going to try it.
If you're not pressuring things up at wide open and not turbocharged, I don't see a reason to do it. If you're worried about oil vapors in the intake, the seperator method is a very good one and an oil with a low NOACK like Redline would help.
I run a breather on each valve cover.
Primary reason is to vent crankcase gasses under WOT. The stock system had trouble keeping up once I nearly tripled the factory hp.
Secondary is to keep oil vapors from coating the intercooler. The fresh air side went in pre-turbo which reverse flowed under WOT. After a bunch of miles the intercooler gets coated with oil and loses it's efficiency.
And third, the PCV valve had to hold back 28+psi of intake pressure. I can only imagine how much oil it would blow out of the seals and breathers if the valve failed.
With regular rings I had a problem with the breathers becoming saturated with oil and occasionally dripping on the headers. Once I went with Total Seal gapless, the breathers stay completely dry. One solution I used while using regular rings was breathers with a 5/8" hose barb that routed gasses under the car.
I use a very short OCI partially due to not having a PCV system. I compromised idle and part throttle crankcase flow to keep it from pressuring up at full throttle. Honestly, I could probably use the stock PCV system with the gapless rings but I'm not going to try it.
If you're not pressuring things up at wide open and not turbocharged, I don't see a reason to do it. If you're worried about oil vapors in the intake, the seperator method is a very good one and an oil with a low NOACK like Redline would help.
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