I enjoyed the read, although I had to stop reading last night to get some sleep, and you weren't quite through. I think the idea of the air compressor separators is a great one. Keep us informed of the progress and good luck.

 

Gang:

I'm way too lazy to figure out the whole picture posting thing (although not too lazy to type 100 pages on a Sunday night).

Somebody hit me with an e-mail address and I'll send you some photos to post.

Rob - which direction do you have the check valve acting on the driver's side? Best case scenario is you have completely disabled the PCV system under all conditions. Worst case scenario is that you're pressurizing the crankcase under boost. I guess the question is - which direction of flow are you preventing on the driver's side?

I'm trying to work all of the angles on how your system works, and doesn't work...

 

First of all, thank you for your serious and well-stated opinions ans information. Very classy and more understandable than some of the earlier posts about this problem.

In February of 2003, a little over 20,000 miles ago, I installed the Swanson kit after trying two different seperators, oil breathers on both cam-covers, and an oil breather cap. I have to admit that I've been a little leery of the Swanson kit, especially when I saw 'froth' on the bottom of the oil cap for the first time this winter. I wondered if cold temps and the change in the PCV system were responsible for this. Btw, as it's warmed up here, the 'froth' has disappeared. I'm still confused as to whether the Sk is the cause and I suspect it is after reading your treatise on this subject.

Dan

 

'Rod:

The milky sludge is from condensate (condensed water vapor) in the crankcase, which forms the sludge when mixed with oil. If you wash under you hood a lot, you'll get it on the oil filler cap as well (in addition to about a zillion frozen bolts on the motor - don't ask).

Anything you do to reduce the function of the PCV system will promote its formation, but I'm gonna go out a limb and claim that if you leave the portion of the PCV system that functions under vacuum intact and unaltered, you will purge the crankcase just fine.

I'm thinking that what you saw was just a winter thing. Lots of temperature swings, plenty of water in the air, and infrequent heating of the crankcase.

For example, mine (before any alteration of the PCV system) wasn't driven a single foot from late October until just this week. I started it up here and there when I was around, maybe 5 or 6 times, and let it heat up under idle.

The bottom side of my oil filler cap was covered with milky sludge when I checked it last week. All gone now, of course, since the vehicle is being driven.

 

Excellent, and I believe accurate post. I arrived at the same conclusion as you and took out the dime kit and put in CH separators as well.

Regards,
Mark #2

 

I haven't read the rest of your post, but the pinhole is no "claim". it's absolutely there. I can promise you this because I am looking at it right now. I have an old L intake on the floor by my tool box and if you look into the fitting from the INSIDE (normally under the puddle of oil) you'll see it inside the 90degree fitting. the metal fitting that is screwed into the bottom of the lower intake that the lower pcv hose goes to has a small orifice or "pinhole" in it. the fitting is about 3/8" inner diameter, while it constricts down to an orifice that is 1/8" or less.

just some input.

later,
chris

 

Superfords:

Thanks for the confirmation. It makes it even more amazing how huge the flow is through the system under boost.

It's entirely possible that the orifice increases the atomization and entrainment of the oil by acting as a sharp-edged nozzle. Food for thought.

I'm gonna play around with restricting the line to the upper intake plenum as soon as I can track down a little bit of 3/8 inch aluminum rod for drilling on.

I just drove around for 75 miles or so, mostly stop-and-go, and collected a bunch of oil in the first separator, with a noticeable bit carried over to the second. Now I'm starting to freak out a little.

What are you running on the MOST AWESOME Engine Of Doom? I showed those photos to my brother (a big-time car freak and engineer for Daimler-Chrysler), and his comment was...

"That's the most awesome thing I've ever seen"

...and he works at the Chrysler Tech Center a lot (read - "racks of Viper motors stacked to the ceiling")

I have to agree with him.

 

Well this ("T" connected to the upper intake plenum),is the outlet to your PCV system at wide open throttle, a part of blow-by gas flows into the plenum through the connecting hose , because under this condition, the intake manifold vacuum is not so strong to introduce all blow-by gases increasing with engine speed directly through the PCV valve. ... The most important line....fresh air inlet and a foul air outlet.


The drivers side is simply the metered inlet....... thats why it is not vacuum assited on that side.


Your on the right track as far as the best solution....thou.

I would add one thing that will help. After or before the PCV valve make your own in-line baffle before your separator.

 

seriously Alan......you would have a hard time taking a leak with out a picture ....... tell ya what, I show you what he's talking about this weekend

 

Red:

I'm thinking that it might be YOU that ALMOST understands the Lightning PCV system. Work with me here.

Your assertion is that the passenger's side tube to the upper plenum is the path for crankcase vapors to enter the intake (and eventually be burned).

Let's look at the various scenarios of boost/vacuum and try to reason this out.

First, you have the situation of vacuum in the lower intake (under the intercooler core). This is when the supercharger bypass valve is fully open (and the blower is more-or-less out of the equation). Effectively, you have a standard, naturally-aspirated 5.4 (with low compression). This is the mode that you run in, by my estimate, about 95+ percent of the time.

The PCV system flows in the "forward direction" (from driver's side to passenger's side) in this mode. Per the immutable laws of the universe, fluid (and air is a fluid) flows from high to low pressure (with, not against, the pressure gradient). Since the passenger's side valve cover (at the non-vorking PCV valve) is connected to higher vacuum (both the upper intake plenum and the lower intake) than the driver's side valve cover (which is connected to the rubber intake boot at much lower vacuum), that's the direction of the flow. The pressure in the intake boot is higher than the pressure in either the lower or upper intake plenums. Were this not so, your intake system would actually be EXHALING out of the MAF to the airbox.

An aside - your assertion that the system is not designed to provide fresh air to the crankcase is wrong. This is, at the least, a question of semantics. You can not effectively vacuum blowby out of the crankcase unless you have huge vacuum pumps capable of pulling a total vacuum on the crankcase. Rather, a relatively weak suction in used to constantly pull vapors from the case, replaced by clean air from the inlet (under the vacuum condition, at least). If you look at it from ther point-of-view of the tube on the driver's side, you are actually BLOWING high-pressure (relatively speaking) air INTO the crankcase, which forces dirty crankcase gases out of the passenger's side valve cover. Semantics, but the fact remains that constant fresh air introduction into the crankcase is an essential feature of any street PCV system.

Anyhow, having established this, we need to determine where the dirty crankcase air (exiting the passenger's side valve cover) heads next. There are two possible flow paths - either through the like to the lower intake, or through the line to the upper intake (supercharger inlet). Naturally, it will flow to the point of lowest pressure (highest vacuum). Due to the nature of the plumbing, the tube (of the two) with the highest pressure (lowest vacuum) will also flow in the "reverse" direction to the highest vacuum source as well.

Now, again recall that fluid frows from higher to lower pressure (along the pressure gradient), or, if you like, from lower to higher vacuum. Naturally, the pressure HAS to drop as you progress through the entire intake tract, with the highest pressure in the airbox and the lowest pressure (highest vacuum) in the lower intake for flow to occur in the proper direction (with the supercharger bypassed). The highest vacuum point in the passenger's side PCV system is in the tube connected to the LOWER intake. Were this not the case, the motor would be EXHALING upward through the intercooler core and into the upper intake plenum through the supercharger bypass.

I see NO WAY that the vacuum in the upper intake could be higher than the vacuum in the lower intake with the supercharger bypassed. Therefore, the dirty crankcase gases have to travel from the passenger's side valve cover to the lower intake through the corresponding line. Additionally, there also has to be some flow "backwards" through the upper line (sucked out of the upper intake plenum to the lower intake).

Maybe you can prove otherwise.

To be continued...

 

The second of the three conditions is when the motor is under boost. Now you have the lower intake manifold at high pressure. Very high pressure, in fact, relative to any other point in the intake tract. This is possible without the engine "exhaling" through the intake tract because the bypass valve is closed, sealing the lower intake from the upper and you have a positive-displacement pump (the supercharger) plumbed tightly into the intake tract.

Flow through the tube connected to the lower intake will be clearly in the "reverse" direction (from the lower intake to the valve cover), at high velocity and volume (I realize there is a restriction in the line). The flow through the tube to the upper intake will be in the "forward" direction (into the plenum), as the end at the "T" is essentially at boost pressure (very high), while the end at the plenum is at low pressure (under vacuum).

Since the PCV valve is non-functional (might as well just be a piece of straight tubing), the tube right at the valve cover will also be at relatively high pressure. Contrast this with the tube at the driver's side valve cover, which is at low vacuum. The flow through the crankcase will clearly be in the "reverse" direction, with clean air introduced via the passenger's side valve cover (recirculated boost) and dirty crankcase air being pushed (or sucked, depending on how you look at it) out of the driver's side valve cover. The tube to the upper intake plenum will simply flow recirculated boost (which has entrained oil in it from the lower intake).

Were this not the case, there would be NO WAY for oil to be deposited into the intake boot near the penetration for the driver's side PCV line, nor would there be any reason for Ford to use a non-functional PCV valve on the passenger's side. So again, the line to the upper plenum is not carrying crankcase vapors under this condition.

To be continued...

 

When all of you get this figured out and it finally works, I just might install your improvement.

But, in the meantime, I'm going to give my 2 cents.

Remember this... the PCV valve was NOT invented to improve performance, longivity(sp), or anything else. A PCV valve was the FIRST mandated anti-pollution device and was NOT used on engines until 61 or 62. Before this time, engines came with breather tubes ala small block chevies or breather caps like on 221 and 260 fords.

There is a positive point in having a pcv system, and that is to scavange moisture from the crankcase while the engine is cold (short trips), a complete warm up of an engine burns off this moisture and could, in the olden days escape through the breathers.

The valve cover design is bad for this. Witness the very tall breather caps on midget cars, etc. They dont even have to contend with the cams in the heads.

 

Finally, we have the third condition, which is the only one where the line to the upper intake can logically carry crankcase vapors.

You can imagine a transient part-throttle condition where you are ALMOST making boost, and you have just a very low vacuum in the lower intake. This would be a condition where the bypass valve is partially closed. Specifically, we're talking about a condition where the pressure in the lower intake is exactly (or nearly exactly) equal to the pressure in the rubber inlet boot.

Under this condition, the tube connected to the upper intake plenum would have the lowest pressure (highest vacuum). Naturally, the pressure has to be lower there than in the intake boot for flow to occur in the proper direction (toward, not away from the supercharger). The Pressure in th elower intake can be higher than the upper plenum due to the presence of the positive-displacement pump (the blower) putting energy into the intake flow.

As such, flow through the tube to the upper plenum would be in the "forward" direction (toward and into the upper intake). The line from the lower intake would flow in "reverse" (out of the intake - from high to low pressure), and the flow of crankcase gases would be from driver's side to the passenger's side (from the relatively high-pressure intake boot to the lower-pressure upper intake via the crankcase).

In this unusual, transient condition, the upper tube of the "T" would indeed be the path for crankcase vapors to be deposited into the intake, to later be burned.

What am I not understanding?

The only thing I can even guess is that the influence of the spinning supercharger, even while fully bypassed, puts the lower intake at higher pressure (lower vacuum) than the supercharger inlet. I supopose this is possible, but I can't see it. If this is the case...

There would be no reason to have the tube to the lower intake plumbed into the PCV system. You would need a tube to purge all of the deposited oil in the lower intake, but why not just restrict it to a pinhole and return the oil to the crankcase? Thsi scenario doesn't fly with me.

Additionally, the line to the upper intake clearly isn't the path for crankcase vapors under boost, or the Lightning would have been engineered with a proper PCV valve. The non-functional valve is CLEARLY put there to allow the PCV system to run in both directions, and when it runs in "reverse", the vapors are purged via the driver's side and into the rubber inlet boot.

I still think that I have it correct.

 

WE dont have to reason out anything because the tree huggers who put these vapors into our cylinders dont care about your boost/vacuum senarios......... Its no assertion its FACT.

Dont forget the simple FACTS #1 that in a closed metered PCV system you have a metered inlet and and equal AIR MASS outlet Period. and #2 engine vents and this venting is burned. You can guess the boost/vacuum scenarios all you want .....its irrelavant.
actually BLOWING high-pressure (relatively speaking) air INTO the crankcase ??????????????????????

at what point dose this happen???? when you crack the throttle body its sucking ...not blowing ....the truck would die.

 

I need a blushing smilie thanks to you and your brother for the compliments.

as for the "engine of doom" I've got a little something up my sleeve, but let me get some miles on it first and see if it works.

I still think that a decent baffle filter would do the trick. as I showed before, the valve cover baffle on these engines is just an empty hole. if you could fill it with a screen or filter (steel woolish filter like in the back of a 5.0L engine?) it would cure a large percentage of our problem.





later,
chris