Anyone removed the PCV system ?

David Neibert

SCCoA Admin
I'm sick of this thing sucking or blowing oil into the intake plenum and eventually into the combustion chambers. I've tried fuel filters and more recently an oil seperator, but I'm still getting alot of oil in the intake system.

A few questions.

What function does the small vacuum hose that attaches to the hard line pluming for the PCV valve serve ? The hose I'm talking about goes into the passenger side firewall.

Where can I get filters to either install in the valve covers or remote mount with a hose running to each valve cover ? Or would I be better off mounting a vented catch can and running a hose from each valve cover ?

I understand how the current system works (driver's side metered air in...passenger side metered oil mist out) but not sure what the adverse effects if any would be, of removing the PCV valve system.

David
 
There is 3 problems i can think of that you MIGHT have if you remove the PCV system and just install filters in the valve covers. Fist off it tends to make the car run lean, i havent tested this myself but Pro-M and others say it does. Second forget about passing a visiual inspection if your county has emisions. 3rd Sometimes you develope oil leaks from seals, the slight vacuum the PCV system puts on the crankcase does help keep oil inside the motor. If you car has low mileage and you dont run synthetic oil it should be OK.
 
I know what you mean! I have been looking at this for a couple of years and this winter may install a new system.

This link has info on a catch can installed on a car that has a PCV similar to ours:

http://www.angelfire.com/ca/DrOhm/hybrid.html

From what I have read we do need some kind of vacuum system to assist in removing these crankcase vapors. Probably not enough just to vent them to the atmosphere unless we had some bigger vent holes.

I'm looking at putting together a Moroso system like they use on race cars. Here are some part numbers for reference:
-----------------------------------------
MOR-22640 – pump
MOR-22641 – pump
MOR-63910 – bracket
MOR-64885 – 5” pulley like smog pump

Accessories:
MOR-64885 V-Belt Pump Pulley, 5" dia
MOR-23520 V-Belt Crank Pulley, 25" dia
MOR-23523 V-Belt Cankshaft Pulley, 4" dia
MOR-83844 Drive Kit, BBC, (includes 25" V-Belt Pulley)
MOR-64886 Vacuum Pump Pulley, Gilmer Type
MOR-85465 Breather Tank

Aerospace – Jegs catalog
026-AC-RFV Relief Valve for Vac Pump
--------------------------------------------------
Still looking for a convient way to mount and drive the pump. It might be possible to drive it off the back of the jackshaft in some way. This solution might be a little expensive, but will get all of oil out of the intake tract. It also should be helpful in ring seating and should be able to handle any of the Whipple boost levels I decide to throw at it!
 
You know the A/C accumulator is a design where the intake tube goes in from the top and reaches down to the bottom of a sealed canister and the oulet tube reaches into the top of the canister and also comes out from the top. What this does is allows any liquid refrigerant to settle at the bottom of the canister and the gaseous refrigerant to pass out the top. Gravity does the work of keeping the liquid in the canister.

If you had something similar to that for the PCV oil pickup, I wonder if it would work? :cool:
 
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David There is a company in ST Charles that builds pumps for this.
The pump will pull a 7lb vacuum in the crank case.It can be about
20 to 30 HP increase.It works the same as a multi stage dry sump.
It take all or most of the air from under the piston.So on the down
stroke ,You have less air pressures for the piston to resist downward
motion.

You may talk to them and get some info.C&L.This is there
buisness and carbs and pumps.I don't have there number handy,but
they should be in your local yellow page under autos-carbs.
I used one of there pumps on a pro-stock HD motor took off .500 ET.
And I had it set up for a 7lb vacuum.

I have an old race friend that raced topgas class.Not for sure but I think
he ran this system.He may be of help.Tell him Randy & Connie from Hot bike magizne sent you he may help in this area.He is in your town,David Williams.
www.fastlanecars.com

RANDY
 
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A friend of mine did the same thing to a big block Chevy. It seems that if you can get the pressure out of the bottom end of the engine it really increases hp. From what info I got from him the higher the rpm. The more power there is to gain. 50hp. is not out of the question. Seems like it would really decrease any kind of blow by too. If any one gets it worked out for our cars let me know. Tim
 
Dave you can do that or get an evacuation system which hooks up to teh headers.,At full throttle the exhaust creates a vacume..Its cheap but some fabrication will be involved
 
DO you have the line from the valvecover to inlet still attatched?

Yes...the complete PVC system is all still attached. The only change I have done is to add some extra hose and an air compressor type oil seperator between the PCV valve on the passenger side valve cover and the inlet plenum. It only catches about half of the oil and I just drained a couple ounces from it last night.

I really don't want to get into expensive vacuum pumps so maybe I'll just try adding a second oil seperator.

David
 
Damons idea would be the cheapest..I have used this type system.
If you get a large one way valve and large diameter hose ,and weld a bung
into the exhaust.It is a slight hp adder but very little.All the oil is burnt
in the exhaust.Any speed shop sells the metal one way valve and weld in bung.

I don't know if the pcv system is metered for any ecu reasons or not.
I think this was your question.

I have an electric oil pump for turbo shut down oiling.I plan to try this
on my new motor.To see if it will pull a vacuum under my pistons.And
delete the OME PCV system.But it would only be good for racing,I would
think.

RANDY
 
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Randy,

I've seen the exhaust EVAC systems, but I thought those could only be used with an open exhaust system and non baffled mufflers. I think the SC exhaust system may have too much back pressure to pull a venturi effect vacuum. I've also heard of people using a smog pump to pull a vacuum, but they don't last long because of the oily mist damaging the vanes.

The mustang turbo guys have tried several ways to get rid of the oil in the intake and about half say that putting breathers on the valve covers is about the only solution, the other half use the PCV valve with a filter or oil seperator and draw unmetered air into the other valve cover and just deal with the poor idle quality. The problem with vents on the valve covers is they don't pull a vacuum and the fumes coming out of the rocker covers isn't pleasant when sitting in traffic.

Those who have converted from a mass air to a speed density system don't have to be concerned with the unmetered air problem. The problem with plumbing it correctly on mass air cars (like ours) is that the only place to draw unmetered air for the inlet side of the PVC system, is prior to the turbo, and since the PCV valve requires a check valve to prevent boost from pressurising the crank case, the only ventilation for the crankcase is back thru the intake side of the PVC system. So when under boost when blowby is greatest they have no vacuum to vent the crankcase. If oil travels back to the intake side before the turbo it will damage the turbo impeller.

BTW, I'm asking these questions as much for my 347 turbo project as I am the SC. Oil in either intake system will cause detonation. I'm thinking about plumbing my 347 like the one in this picture.

http://members.cox.net/turbosn95/STANG/engine1.jpg

Since the SC draws from the PCV valve into the inlet plenum before the supercharger, there is never any positive manifold pressure to restrict flow from the crankcase. I think the bulk of the oil is pulled in from high vacuum such as when suddenly lifting the throttle. If it were from crankcase pressure while under boost, the breather (intake) side of the PCV system should also have oily going into the air intake tube between the MAF and TB. Mine doesn't get any oil prior to the TB.

David
 
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David, I should say all my experience with setup that I have tried are on race
only motors.

On Damons idea this would need to be placed after the cats.The weld in
bung needs to be cut at 45 degrees & welded at at an angle to promote
exhaust vacuum.This will burn the oil,and cure it presents.Bigger the hose
less crank case pressures,positive & degitive.Makes for faster RPM Gains.
This is not my favorite but its a help.And some tech ins don't like it at the track.But its cheap.

The C&L pumps manufactured in your town.Are designed for pulling a vacuum
on the crank case.I would not consider them smog pumps.But the same principle,but hook up different.I would think this would be the best place for info for you.

All race motors that I have been involved with .Had a multi stage dry sump oil system.CARBED,TURBO,OR BLOWER.This is the best,and most exceptable setup.You get good oil pressure with one stage.The next stages
can be used for getting rid of crank case pressures under the pistons,for a HP gain.Then route all lines to a baffled container.This will keep a sealed system
that I think you looking for.I don't know if this would pass smog testing.But I
would think a multi stage dry sump would make for the cleanest burning
engine.And at the same time get some HP gain for the money spent.

Just my 2 cents.I don't spend money unless its to lighten or give HP gains.
I don't think much in terms of creatuer comforts,or EPA standards.But I believe a 4 stage dry sump would give you all that your looking for.

I wasent able to see your reference web address,maybe it will work later.

Good luck and happy driven with your 347 stroker.RANDY
 
Damon,

Please excuse my ignorance on the subject, but what is DFI ?

BTW, that's the same intake I'm using on the turbo 347, except I'm making a plenum that will fit under the stock hood instead of using that huge elbow.

David
 
Its a stand alone fuel injection system based on a GM computer..You can tell by the IAC valve which is the GN type on the TB..Its speed density ..You get rid of the mass air (One of the biggest restriction on a turbo car)..Im trying to remeber if Wayne Ing had DFI or not or was it a motech setup..I was looking right at his car at carlisle
 
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