The Positive Crank Ventilation Valve is a check valve....a ball check I would think or a spring loaded flapper\gate type. Open when the intake is on vacuum and closed on boost...They do leak if dirty or worn...My Turboed Merkurs made me aware .... Maybe a higher quality brass valve would not be a bad idea in the same line...a double seated check...kind of. Something with a light enough gate or ball that the engine vacuum could draw open and suck out the emissions.... My Merkurs have a 1/4 " line tied into the intake of the Turbo compressor. THis Line terminates at the suction end, on top of the Valve cover...In a Filter media....The oil that is draw out of the crankcase/valve train is coalesced and falls back into the engine. They do need to be cleaned/flushed once in a while.
A vented filter Like most have put on the Lightning could decrease the vacuum in the crankcase....it could also induce a combustible mixture in the crankcase....I would think. A gas blanket on the crankcase probably keeps the corrosion to a minimum on parts that are never splashed or washed over with oil. Few if any but maybe some.


My Turboed Merkurs have a Vacuum reservoir to cope with vacuum demand accessory items when in boost. No idea if the Lightning has a reservoir. I doubt it.

Correct me if I'm wrong....Posted in Reply to LIGHTNINGROD

 

I agree Twisted I just didn't want to get this started. It also lets unmetered air enter the engine and thats the last thing I need. I already run a very high octane to keep detonation away. Good Post buddy. Are you going to be ready to go to Holt and race Jan 6th?

 

Ready an waitin'...

 

Thanks for the added info.

I ordered a brass spring-loaded poppet check valve(p/n-7775 K52) from mcmaster-carr supply co. in Atl. Ga. that was recommended in LS1tech.com. It cost $9.97+3.00 shipping. LS1 said the valve is placed inline between the PCV valve and the intake plenum with the 'flow' towards the plenum. I haven't installed it yet but plan too soon(I have to get 2 barbed fittings for the hose insertion). I want to keep the oil from being 'pressurized' up into the intake--it doesn't 'belong' in there.

Dan

 

Proper chip calibration can address the "unmetered" air issue; or so we have all been told.

 

You don't need a chip! This is why!! EEC 101

Injector pulse width is based largely on calibration information stored in memory. The processor contains a pre-determined calculated injector pulse width for fuel control. As operating conditions and and air flow change the calculated pulse width must change.

In order to determin what changes the PCM needs to mak, it looks at information from the input sensors and estimates how much fuel is needed. When A/F is controled using this pre-calculated base pulse width, it is operating in (OPEN-LOOP). Your truck goes into this mode when you are at WIDE OPEN THROTTLE.

(Pre-calculated-meaning the base pulse width is set by a table of peramiters set by the calibrator)

Closed loop is when the The PCM is controling A/F ratio receiving input from the O2 sensor. By monitoring exhaust gas oxygen levels, the processor can determin if the air/fuel mixture is either rich or lean. Closed loop control of the fuel system is only possible when these conditions are met:

Engine tempature is above calibrated level.
TP sensor is at part or closed throttle, and not wide open throttle.
Other factors in EEC strategy are thermactor air must be down streem or bypassed, and the O2S Sensor voltage must be switching regularly between high and low voltage signals.

PCM
1.) Detrermins warm cruise mode
2.)switches to closed loop
3.)provides balanced (14.7:1) A/F ratio.
4.) Monitors O2S input.

This means that your PCM is receiving information on AIR flow from the MAF,O2S sensor,tempature sensor and a few others to determine injector pulse width. Not based on a pre-determined set of peramiters.

If there was enough air in the crank case vapor to make a difference for combustion in the cylinder Ford would have put a sensor on it.

For those who still don't get what I put up. If I took an exhaust hose while the truck was running and put it up to the air-box, do you think there is enough air in those emissions to keep it running? Hell No! More (CO),(HC) and (NOx) then O2.

Same theory for the Engine oil vapor going into your intake. The auto makers can't vent vapor into the open atmospher. Do NASCAR,Top fuel engines have a PCV? No way!

Thor.

 

Mostly I was trying to address the oil drawn into the intake on the Lightning. Not really aiming at the vapors.

 

If that is EEC 101 I would hate to see your version of EEC 102.

Maybe we are talking about something different here. I am thinking about the open element crackcase breather not a system that still has the PCV valve. I would think the open breather would significantly change crankcase air pressures.

I would also like to know why some of the tuners have gone to the time a trouble to redo calibrations when an open breather is used? It would seem that they don't put a sensor in there because the set parameters are calibrated for the stock motor and crankcase ventilation. You start scewing with that and you might need to tweak recalibrate your PCM.

Thanks for your thoughts.

Is the stock A/F really 14.7:1. Who the hell runs a 14.7:1 A/F mixture if they want to make some real power?

 

At least for the time being, I'm going to keep the PCV in line(with the 'added' check valve) to see if that will keep the unwanted oil out of the intake area. The LS1 theory/fact(several over there have said "it works") is that boost(especially extra boost--that I have) is 'over-pressurizing' the crankcase, thereby forcing oil into our intakes. Supposedly, the added poppit/check valve prevents(or reduces) this.

Thor, I currently have an oil breather on the left cam cover(tube removed--intake boot 'hole' plugged) and an oil breather cap in place of the stock oil filler cap. I agree that the chip shouldn't need reburning because of this but, would you agree that oil in the combustion chamber could cause detonation because of dilution of the A/F charge?

This should allow the PCV valve system to still work but, with less pressure in the crankcase. The reason for me adding the 'LS1'(remember, this came from their supercharger/turbo board--they are installing these 'power adders' onto their LS1s) valve is that with the above oil breathers on my eng., oil still seems to be getting into the intake--and I don't want to 'mess up' my new BABolt th/body.

I will post my findings as I check the oil situation.

Dan

 

LightningRod - I have had this set-up for almost 5000 miles and I have no oil in the intake track. I have also heard that if you run 1/2 quart low you will reduce the problem.

 

NeedFourSpeed,
I was addressing the fact you don't need a chip to delet the tube on the drivers side that is up stream from the PCV tube. If you remove the tube on the drivers side at the cam cover and plug the tube. Start the truck and put your finger over the cam cover niple you get a vacuum at idle. (Negative pressure)

Once you have done that, keep your finger over it, at the same time pull back on the throttle linkage bring up the rpm's it stops. It' has little to no pressure. It won't move your finger. The reason we are getting oil in the tube and on the throttle body is, the Supercharger draws in the crank case vapor.

As the supercharger draws the air over the tube at the rubber boot location it creates a vacuum. The vapor is oil in a mist form. It accumulates over time and you find a small puddle where the boot and throttle body meet.

On the PCV side the piston in the valve shuts off the positive pressure at 3/4-WOT. Doesn't do a good job. Still not enough
to compensate for. I would like any tuner to show data to prove a chip is needed. I don't suggest removing the PCV and installing the air filter in it's place. Do it on the drivers side! Not that you can't remove the PCV. Just find a better working aftermarket one. Or live with Oil smell in the cab when driving on those hot days.

I work at Ford in Calibration. I will do a test off my own truck to prove it is not needed. How can a tuner compensate for air that is not measured. They assume? If they say with an A/F meter, that is bull. They need to Post the data to prove the there is a sufficient amount of air and if removed makes a lean condition. That's all. Just show me the data.



LIGHTNINGROD,
Our trucks do not produce enough vapor to break down the A/F in the cylinder. A stuck open PCV valve could cause a rough idle and run condition over time. Even Plug fouling. If you have detonation it won't be oil vapor. Bad gas, plug gone bad or a chip that needs to be tweeked for the gas and area of the country you live in. Weather conditions altitude all play on performance chips.

Thor.

 

The point I was trying to get across is the coalescing media. With the vacuum hoses still attached to draw the crankcase vapors out. Indeed if the PCV is leaking by overpressure could exist in the crankcase. With the vacuum drawn through this sort of media...the oil coalesces and the vast majority of it falls back into the valvetrain. I run 16 #'s of boost on My cars. the oil in the intake boot is still there but reduced drastically. I do enjoy the discussion and hope to learn something....When I'm in boost the turbo seems to maintain pressure longer at higher levels than the Lightning. Pushing 12-13# there and it peaks..then slides a bit...
Think I`ll try a filter on the vacumm line...not too fine a micron.
If it does plug it just gets sucked out of ..say a grommet where I will try and mount it in the valve cover. Clean it and back in service..no oil in the intake..I hope.

 

To answer NeedFourSpeed, Yes...Ever since I started going with just under 6 qts of oil (about 5.6) I have never again seen the oil in there. I got this idea from SVT over the phone a couple months ago. I can't knock it, becuse it works for me.
Gary

 

been telling most folks for close to a year now, that running a 1/2 qt. less, will help the problem.