No crankcase vent?

[95tsiawd6blt]

i remember seeing a few cars at the shootout, and i was looking at a few for a good 10 mins, i noticed that a few cars on the valve covers, they have both the breater, and the pcv blocked completely off. Their is no other spots that were cut open to vent, why would they do this? wouldnt there be way to much pressure building up, and not let the crankcase vent?

 

[kenamond]

i remember seeing a few cars at the shootout, and i was looking at a few for a good 10 mins, i noticed that a few cars on the valve covers, they have both the breater, and the pcv blocked completely off. Their is no other spots that were cut open to vent, why would they do this? wouldnt there be way to much pressure building up, and not let the crankcase vent?

I certainly wouldn't recommend this to anyone. Maybe they had some other modification that relieved the crankcase pressure that you didn't see, but I doubt they had a functioning PCV system.

 

[olmytsi]

I doubt that..it's usually the opposite. People add extra vents to relieve crankcase pressure.

 

[95tsiawd6blt]

well doubt it if you must, but i checked out the car for a while, def did not have any extra ports coming off it to release. Both pcv and breater were capped off

 

[nightspeed87]

Normally ppl put a a threaded fitting in the pcv side to take the pcv valves place, then connect a hose to it and to the vc breather, and let the two hoses hang to the ground in the air draft under the car, at least thats how mines is.

 

[kenamond]

Normally ppl put a a threaded fitting in the pcv side to take the pcv valves place, then connect a hose to it and to the vc breather, and let the two hoses hang to the ground in the air draft under the car, at least thats how mines is.

But then you have no PCV system. Blowby from the compression stroke (fuel/air) and exhaust blowby (from the power stroke) sit in your crankcase and settle in your oil. The "V" stands for ventilation.

Also, many have idle issues when there isn't a PCV valve; the car is designed to pull air through the PCV valve under idle, and if you block off the nipple on the IM, you lose that extra air. Also, the PCV valve is a metering orifice, so airflow through it depends on IM vaccuum.

I'm too lazy at the moment to dig up a long thread discussing this, but the end result is that there are ways to address all of the PCV issues without disabling the PCV system. These problems include 1) PCV valve fails too often causing boost leaks, 2) oil makes its way through the PCV into the IM, 3) oil makes its way through the VC breather into the intake pipe, IC pipes, IC, TB, and IM.

The solution as I recall is:

- Install a cheap, non-OEM PCV valve (or OEM if you wanna pay 4x as much), filter/catchcan, and check valve between the PCV fitting on the VC and the IM, in that order.
- Install a $4 fuel filter between the VC breather and intake pipe. You could do a catch can here, too, but it can't vent to atmosphere, or you'll suck unmetered air at idle.

FORMONTOYA and romeen were testing this setup, so the thread has them all over it. FORMONTOYA mashed a rim and hasn't been able to put mileage on the setup, but romeen has. The totals are something like $40 with no catch cans. That includes all of the fittings, fuel filter, check valve, etc.

I'm just dealing with OEM PCV valves and a $4 fuel filter on my VC breather.

 

[nightspeed87]

But then you have no PCV system. Blowby from the compression stroke (fuel/air) and exhaust blowby (from the power stroke) sit in your crankcase and settle in your oil. The "V" stands for ventilation.

Also, many have idle issues when there isn't a PCV valve; the car is designed to pull air through the PCV valve under idle, and if you block off the nipple on the IM, you lose that extra air. Also, the PCV valve is a metering orifice, so airflow through it depends on IM vaccuum.

I'm too lazy at the moment to dig up a long thread discussing this, but the end result is that there are ways to address all of the PCV issues without disabling the PCV system. These problems include 1) PCV valve fails too often causing boost leaks, 2) oil makes its way through the PCV into the IM, 3) oil makes its way through the VC breather into the intake pipe, IC pipes, IC, TB, and IM.

The solution as I recall is:

- Install a cheap, non-OEM PCV valve (or OEM if you wanna pay 4x as much), filter/catchcan, and check valve between the PCV fitting on the VC and the IM, in that order.
- Install a $4 fuel filter between the VC breather and intake pipe. You could do a catch can here, too, but it can't vent to atmosphere, or you'll suck unmetered air at idle.

FORMONTOYA and romeen were testing this setup, so the thread has them all over it. FORMONTOYA mashed a rim and hasn't been able to put mileage on the setup, but romeen has. The totals are something like $40 with no catch cans. That includes all of the fittings, fuel filter, check valve, etc.

I'm just dealing with OEM PCV valves and a $4 fuel filter on my VC breather.

Yea Ive read all those threads. I dont have a useable pcv port on my cyclone anyways so I couldnt use a pcv valve . Curiously enough though you say not having a pcv could cause idle issues, and when I come to a stop sometimes it tries to cut off on me, like the idle cant catch it self, but I always sum'ed that up to me having a lightened flywheel and a bad isc that could cause that. I countered it not cutting off by throwing it in nuetral and coasting to stops and letting the engine rev down on its own a little so it doesnt drop rpms too fast. It doesnt do it in all situations only sometimes will it try to cut, but I have seen it idle surge pretty bad two or three times but it will always stop and not continue.

Well tell me this, would it at all be benefitial if I just put the vc breather line back stock ( w/ a fuel filter of course ) into the intake arm? ( While still leaving the pcv off as is )
Or would that not matter since there wont be any pcv hooked up.?