92slowmaro

iTrader: (22)

ok so its been awhile since ive completely deletted my pcv system. i put a breather on the oil cap and a breather on the rear of the driveside valve cover. and just capped off the ports on the valve covers and tb.

did i do something or is there suppost to be oil residue on areas around the breathers? any cures?

its a 2000 ls1 motor by the way.

thanks,
ryan

JasonWW

iTrader: (2)

You need to get those blow-by gasses out of the engine somehow. It's building pressure and bringing oil with it.

92slowmaro

iTrader: (22)

so no matter what i have to have a vacuum hose running from the valve cover to the intake manifold?

BackinBlack02SS

iTrader: (7)

No, the oil residue is normal. If you had a pcv system, you would just be getting more of that oil sucked into your engine.

bczee

iTrader: (12)

The hot gasses and blowby is pushing the pressure out of the engine and since you have removed the PCV System and have put breather on the valve cover. It is pushing the air, gasses and blowby out of the engine through the breather and Oil is being pushed along with the air. You will have to live with this oilly mess unless you opt to go back to a PCV system or a Vacuum system.

Many use the PCV System with a Catch can to seperate the oil from the engine air/gasses from entering into the T/B.

There is a FAQ on using your AIR pump as a vacuum evacuation system. You might look into that.??

There are many debates on using a PCV system with Breather(s).. that is getting un-metered air into the intake system. I have not seen any real answer to that debate.

JasonWW

iTrader: (2)

That's not really true. The air going into the intake is metered by the PCV valve.

I'm thinking about a crankcase evacuation system like they use on drag cars. They use the exhaust system to create a low pressure area (which is like vacuum) and pulls the gasses out through the exhaust. Like this:
http://www.jegs.com/webapp/wcs/store...10002_21252_-1

I've heard these systems can work too well and end up sucking more oil than usual. I think that can be addressed with specific sized orifaces to control it.

bczee

iTrader: (12)

The PCV valve doesn't meter the fuel mixture as the port is on the T/B which is after the MAF, the PCM has already done it reading and adjustments of the fuel mixture via the MAF and other Sensors prior to the PCV port on the T/B.

That was what my concern on Un-metered air when using the PCV system with Breathers. The PCV jobs it to restrict and seperate air/oil from the Crank Case air/gasses. With the Breathers on a PCV system, you no longer have a sealed system and that the T/B would be drawing air in. As I have stated, there are many debates on this subject, but I have not seen any conclusive answers.

Yes.. using the Exhuast would be one good option. But as you have stated.. it has it pros and cons. I think one has to consider which system would work best for your car and driving situations. Evacucation system, PCV, Breathers.

JasonWW

iTrader: (2)

I didn't say the PCV valve metered the fuel mixture, it does meter the amount of air let into the intake manifold. There is a difference. Since the amount of air a properly working PCV valve lets into the intake is going to be a known amount under several different conditions it makes sense that the computer was already programed to compensate for this small change.
Originally the PCV system was designed as a smog related device to reduce unburned fuel from being released into the atmosphere. That's all. I think it was the late 60's or early 70's when they first came out. Older engines like the small block chevy had a oil fill tube with a breather stuck on top going into the engine through the intake manifold base. The gases just blew out or else they ran a tube down under the vehicle so any oil would run down there. In fact, that's not a bad idea.

If we revert back to the older systems before the PCV valve came into being, we may be OK, although enviromentally damned.

You could just run a rubber hose from both valve covers down to under the car into the air stream. As the air moves under the car and across the end of the tubes it creates a weak vacuum and draws the gases out. Any oil will also drip through. Now if it gets splattered under the car, that would suck, but if we installed some kind of seperator it may work real well. It may even pay to run long lines to the back of the car so the oil will not make a mess.

As far as the throttle body, just cap that plug above the throttle linkage. All it does is provide filtered air into the valve cover anyway.

92slowmaro

iTrader: (22)

interesting. it looks like i may infact go the catch can route. but its ugly looking.

bczee

iTrader: (12)

Yes, I have the down draft tube on my original 48 Ford F-1 truck, Lucky it is not running right now or I'd be putting a can or pan under the tube to catch the oil while it is parked.

Yes, the SBC had many types of PCV system... from the Filler Tube you stated on the front of the Intake mainfold to the rear port with the internal (lifter valley) oil catch can that my Original 57 Chevy had. Original they were not used for PCV but to vent the engine, next came (smog efforts) to route a tube from them to the Air Cleaner and later came to modification to use a PCV valve and route it to the Carb or ported vacuum port or a carb. (What a nightmare those days were when trying to be smog compliant in California, LOL) But I am Glad that I did away with all of them as I swapped the engine(s) out for later model engine and just used breather (back in the 60's and early 70's), a bit messy but who cared back in the days, I remember using shop rags around the Breathers to catch the oil, had to change them every once in a while LOL.

jtl12419

iTrader: (13)

Does anyone have a schematic for how the PCV system is hosed on a stock LS2 or LS7.

I am trying to figure out how to replicate the stock : I have 6 holes to connect

2- on pass valve cover
1-PCV type hole in drivers side rear valve cover
1- vent tube at the top of the TB
1- suction tube at the intake behind the TB
1-valley cover vent under the intake, behind the TB