1991z28ragtop

My 1991 has a Procharger and in boost i'm still getting blow by. I put a catch can in line but it still blows oil out of the valve covers mostly on the passenger side. I put in a TEE connected the left and right valve covers going into the catch can. I'm thinking I should eliminate the PCV valve completely. Any suggestions????? getting tired of continually wiping oil off the engine.

Guest

Power and E.T?

antoine

On my paxton setup I have rubber hose going from both valve covers to a tee then to the paxton air filter so when I go in boost it sucks the crankcase pressure out. And they make a Pcv check valve also

TTOP350

iTrader: (8)

Sounds like you need to do a leakdown test. Also make sure your intake gaskets are ok.

gta324

You should not have a PCV valve at all when installing a procharger (atleast if you do It by the book).

I also had problems with oil leak, I went with "free flowing" breathers in both valve covers and that made things alot better, would still sweat some oil from crank sealing so I got a air pump to suck from valve covers under boost but I did a rebuild this winter so dont know if I need it anymore..........

TTOP350

iTrader: (8)

Yes I forgot to add the stuff about pluging oil and vent lines that go back into the Tbody from the valve covers.
If I remember correctly,you have to reroute the valve cover lines to the blower inlet side and there are checkvalves you can buy if you want to keep the PCV and keep the car E legal.
Again, its been a few years since I installed a kit (I've put on about 60-70kits in my day) soo check Procharges instructions.

86Z

iTrader: (4)

i put a breather in my pass valve cover and took the pcv off per procharger's instructions, i had nothing but blowby smoke coming out of hood, etc... i put the pcv valve back the kind with the ball in it, and it's fine, no blowby no loss of boost... this is with 14lbs

TTOP350

iTrader: (8)

Have you done a leak down test lately??

86Z

iTrader: (4)

my motor has 16k on it... when i built it it checked out fine

Orr89RocZ

iTrader: (20)

My turbo car had a blowby issue that turned out to be loose intake manifold bolts and it pushed the intake gasket out. I have no PCV, just each valve cover vented to a moroso catch can

vortec350s10

I have two open breathers on one valve cover and a pcv valve with an inline check valve on the other. No problems here. When I only had one open breather and a oil plug I had some oil coming from the breather, but not a ton.

sailtexas186548

iTrader: (2)

Im having some blow by issues as well, I'll be checking intake gaskets soon

Kingtal0n

For best engine life, best oil life, and best fuel economy and cleanest engine... ALL daily driver engines that wish to have these features SHOULD use a proper PCV system.

If you are running a turbo/supercharger, then the crank case ventillation should tie into the COMPRESSOR INLET, after the air filter, and before the turbo/supercharger. When the system is in BOOST PRESSURE, the air inlet will present a pressure less than that of the crank case, and air will be pulled out of the crank case... that includes oil vapor, so using a proper catch can is recommended, lest oily air be pulled right into the compressor wheel. Over time that will lead to an oily intake duct, and oil coated intercooler plumbing.

During normal driving / off boost situations, you can use a 1-way PCV valve between the valve cover and intake manifold, like most OEM turbo vehicles come with, to improve PCV function for daily driving, and it will seal shut during boost.

The benefits extend beyond engine life, and oil quality. A proper PCV system can yield horsepower as well. Big blocks running a large displacement blower can yield over 75 additional horsepower when using a dedicated vacuum pump to pull a vacuum on the crank case during boost. All engines exhibit some degree of blow-by and looser engines with larger tolerances (piston wall, ring gap) will have more by design.

TPI_BLAZER

iTrader: (1)

Bear with me here as Im trying to understand how a PVC system works....

Ive been searching a bit for a solution to some blow-by issues Ive been having. Ive read all sorts of remedies and different configurations/combinations of PVC syatems and breathers ect.

One thing I have'nt seen....and this is hypathetically speaking...could you run 2 seperate catch cans, 1 off each valve cover?

DAVECS1

iTrader: (2)

A properly working PVC will help to properly evacuate the crank case even when done correctly on a forced induction car. The valve is a one directional valve. When you are in high vacuum low load situation the valve keeps you from sucking oil out of the engine, like an ls motor does. When the vacuum decreases the valve closes up and the mild vacuum present and the crank case pressure are allowed to vent. The optimum way to set it up is to have a PVC on one cover and a breather or catch can and breather on the other cover. That way the PVC can pul fresh air throught the engine, to evacuate the crank case. Catch can will help in high load situations by providing a path for positive crankcase pressure and a path to siphon off an oil that gets out.

TPI_BLAZER

iTrader: (1)

So to clarify, the catch can would go on the pass side because the PVC is on the driver side.

Kingtal0n

PVC = polyvinylchloride
PCV = positive crankcase ventillation

Oil vapor and crankcase vapors are sucked out of the engine by intake manifold vacuum under normal operations including wide open throttle, EXCEPT when the engine is forced induction based. In forced induction situations, crankcase ventillation is applied to the crankcase via vacuum from the compressor inlet, the only place in the intake tract where pressure is guaranteed to be lower than atmospheric.


Q:
Can I run dual catch cans?

A:
That is not POSITIVE crankcase ventillation, that is simply ventillation. The positive means that different pressure values attribute to net flow of molecules from the crankcase - to wherever. Some engines utilize a vacuum pump driven by a belt as an accessory to suck crankcase vapors out at a high rate, it is not always the intake manifold or turbocharger inlet that is used to create a functional PCV system.

Q: Whats in crankcase vapors?

A:
One of the reasons to get rid of crankcase vapors is because they may contain harmful gasses or other molecular components. The only thing that SHOULD be in the crankcase, at any time, is engine oil. Period. If we can suck every possible impurity from the corner(s) of an engine by applying a vacuum to it under normal operations- well, that is a magnificent idea! Take everything out, leave the oil. The oil filter is designed to remove impurities that happen to be floating in the oil as it passes through the layers of filter material. The PCV is designed to pick up molecules not found directly in the liquid oil.

Q:
Filtration? I need PCV to keep my engine clean? Thats it?

A:
Although filtration and clean engines are benefits, they are not the main benefits to PCV in some cases. PCV is also attributed to a tighter ring seal during combustion. That means better fuel economy. Also, there are reports that indicate a functional PCV system can increase an engine's horsepower output anywhere from +3 to +80 Depending upon the application, the 800 horsepower blower big block 454 CID 21PSI of boost Leaded race fuel engine would probably pick up 50 or more horsepower from the use of a vacuum pump if it was sealed up right.

daverr

iTrader: (1)

get rid of the pcv valve. I dont run a PCV valve in both of my turbo cars.

PCV valve will not create enough vacuum in the crankcase to aid piston ring seal. and if it does its because the PCV valve is broken.