CDR info

[Agnem]

Zigg's statements are correct given the realativity of it all. I've been meaning to post a picture taken while looking down the air intake of the Moosestang. It's squeeky clean alluminum in there. The photo caption will read "why I run a road draft tube". I don't think the rear cylinders getting most of the oil has to do with forward motion. More likely, it is the fact that the engine doesn't sit level in the truck, and the CDR opening is in the rear of the intake. The wind going down in there forces the oil to the rear. Like Jim Crochie sings "You don't spit into the wind". I made a condensor for the Moose Truck out of a weed sprayer filter, available at any farm and home supply store. The amount of oil it collects is minimal, but so is the blow by. I should try one on the Moosestang, but just haven't gotten around to it. I rented a truck for work the other day... one of those **** ant little Izuzu cab overs with the 4 cylinder engine. I looked it over, and saw the RDT comming out of the valve cover, making a quick 180 degree turn and pointing down just below the oil pan. One reason I think we see so much more blow by then other diesels is the high compression we have at idle. Our engines are just going to naturally squeek more gasses past the rings then other engines with all that cylinder presure that other motors don't see until they get a significant amount of boost built.

 

[zigg]

I agree with what Zigg says, don't get me wrong, but I do believe they go bad and as a result, get oil in the intake. My thought, after seeing Zigg's picture some time ago, is that the diaphragm (which I think most will agree is there for HIGH vacuum situations to keep large amount of oil from entering the intake) goes bad and then when you really work the motor and make vacuum, oil bypasses or goes through the hole in the diaphragm, causing what I experienced.

My guess is that repeated exposure to this heavy oil-intake contamination would cause catastrophic head gasket failure!!!

No!!

You have to look at the picture closer. The blowby goes up through the CDR valve behind the diaphram. There is nothing to stop it, the diaphram has nothing to do with it, and there isn't any sort of condenser other than the walls of the can to condense oil. it just comes up one tube, makes a 90 turn, and goes directly into the intake, "behind the diaphram".
The diaphram has no hole in it, is held away from the intake opening by the spring, it is solid nitrile rubber, and is sealed in place by the can face pressed against it via the edge being rolled over.

If, and only if there was enough suction from the intake side, the diaphram can get pulled back, and then it would close off the opening to the intake. I put my shop vac on the intake side, and it couldn't pull the diaphram shut(against the spring), so it takes a large volume and vacuum to do it.

Any oil that collects, just gravitationally drips back down into the valley.

Once again, the diaphram has nothing to do with oil, controlling flow(other than being able to shut off the flow due to catastrophic vacuum levels in the intake...obstructed intake?!) and certainly has nothing to do with oil consumption. During normal operation, there should NEVER be enough vacuum in the intake to pull that diaphram shut! If there is, then I'd say you have a lot more to worrry about than oil consumption.

Another analogy would be to have a 1" direct tube from the valley to the intake, and then say that the tube is worn and needs replacing, that's why the engine is consuming oil!!

Look at the pictures...

Zigg

 

[sle2115]

Well, then explain the two occurances and why they stopped with the addition of a new CDR! I have TRIED to make it happen again, there is now no oil in my intake either, so it is doing something!

I will also state that I am no fan of Ford, and feel much of what they design is poor, but I assume this CDR to be a product of IH. It is there for a reason, argue as you may, they didn't go to the expense of putting them on there for looks. Now rather they function as expected or not, that is another story.

The diaphram in my old one did not have such a stiff spring in it either. While I have never "flow" tested one of these engines, I bet there is more intake vacuum than you might think. I have flow tested many intakes though, and to think because something enter the back of the intake that it goes to the back two cylinders is not even close. There is a ton of turbulence in stock intakes, this is the reason you can bolt on a $100 intake in a gasser and pick up 15 to 20% more horsepower, but since there is no fuel in the intake charge (short of the CDR drippings! it shouldn't be such an effect on these engines. I would agree that the nose high attitude of the engine would make a difference as well. But if you don't believe the forward motion has nothing to do with it, sit a glass of water on your dash, or a glass of oil, since that is what we are talking about. As I said, my truck only did it going up a hill, was it gravity or because it was working harder? I'll leave that up to you all, but when changing my CDR fixed the problem, there is little argument that the CDR was the cause, no matter what theory you want to use to explain it, results are results.

 

[sle2115]

No!!

You have to look at the picture closer. The blowby goes up through the CDR valve behind the diaphram. There is nothing to stop it, the diaphram has nothing to do with it, and there isn't any sort of condenser other than the walls of the can to condense oil. it just comes up one tube, makes a 90 turn, and goes directly into the intake, "behind the diaphram".
The diaphram has no hole in it, is held away from the intake opening by the spring, it is solid nitrile rubber, and is sealed in place by the can face pressed against it via the edge being rolled over.

If, and only if there was enough suction from the intake side, the diaphram can get pulled back, and then it would close off the opening to the intake. I put my shop vac on the intake side, and it couldn't pull the diaphram shut(against the spring), so it takes a large volume and vacuum to do it.

Any oil that collects, just gravitationally drips back down into the valley.

Once again, the diaphram has nothing to do with oil, controlling flow(other than being able to shut off the flow due to catastrophic vacuum levels in the intake...obstructed intake?!) and certainly has nothing to do with oil consumption. During normal operation, there should NEVER be enough vacuum in the intake to pull that diaphram shut! If there is, then I'd say you have a lot more to worrry about than oil consumption.

Another analogy would be to have a 1" direct tube from the valley to the intake, and then say that the tube is worn and needs replacing, that's why the engine is consuming oil!!

Look at the pictures...

Zigg

Zigg, so why do you think IH/Ford went to the expense of putting a CDR on the engine? I value your opinion, but don't for a minute think IH went to the trouble of designing this unit, machining parts for it's installation, for it not to have a purpose.


As I said in my post, we can argue about what it does or doesn't do all day, but in the end, changing mine fixed the problem I had, two times in a row and haven't had since changing doing the exact same thing probably 10 or 20 times since...I have a hard time believing that the CDR has no pupose.

 

[Agnem]

Scott, I don't debate that something changed when you swapped out your CDR, and I'm not going to go against your beliefs. However, there are lots of folks who changed them out and did NOT enjoy the benefits you say you derived. IH put the CDR on there for one reason only. To make the engine compatible with emissions required for vehicles in the weight class and in the states or territories it would be sold in. Not only did they know that the CDR would be sucking up oil, but they borred out the rear two cylinders to help the engine burn it thus proving that they knew that is where the oil was going to go. The higher compression generates extra blow by, and this produces a more visible vapor in a RDT arrangement which could have negatively impacted sales, so even in trucks that did not need such emissions equipment, the CDR was retained. The T444E however, uses a crankcase vapor recirculation system in "powerstroke" form, but does NOT in all applications used in IH Buses and trucks. If it were not for federal emissions requirements (and perhaps now some guilty feelings from green sympothetic engineers, raised in a world with heightened environmental sensitivity), engine manufactures would be more than happy to delete all emissions equipment, and run a road draft tube on everything that moves.

 

[dwaymar]

i took my cdr turned it back wards and used the same mounting practice and remounted it then i ran a tube out of it so it will still collect and drain back but also have the affect of the rdt

 

[Ironman03R]

It is my understanding that the CDR will be sucked closed at high RPM to prevent oil consumption. IF thats the case, then it is completly possible that the diaphram wore out or was stuck and could not close off and let the engine suck the vapor in.

 

[zigg]

I agree completely with Mel in what he says about emissions reasons. Every engine that I've seen since the early 70's has some form of EGR(exhaust gas recirculation) and PVC(positive crankcase recirculation) for pollution controll reasons. The other main reason for the CDR valve is to prevent an engine from continuing to run on crank vapours if the intake somehow became obstructed.

I also agree with results. If someone changed out the CDR and it fixed the problem for them, then that's great, but one can clearly see, the CDR has no function connected with oil other than some blowby may pass through it. Can't argue with results, but I think I'd comfortably say that almost all guys who have oil consumption problems that change out the CDR valve will continue to have the same consumption problems.

I will say one more time, I believe completely that the oil in the blowby is a symptom of a worn engine, not a problem related to the CDR valve.

In my case, my last 6.9 was going through 1 quart of oil every 200 miles or so. I removed the CDR, and went with a RDT. Same oil consumption, just all over the road. (also more leaks around the oilpan and both front and rear seals) but the intake was dry. (so the oil was getting into the intake via the CDR, now just dumping onto the road). I believe the increase in leakage is due to higher crankcase pressure due to the engine pushing the vapour out against atmospheric pressure as opposed to the low vacuum in the intake sucking it out of the crankcase via the CDR.)

I also tried to reroute the blowby through various condensers, with some results. I condensed lots of oil, but also had lots of leakage, and overall, same amount of oil consumption by the engine. If I had the CDR inline with the condenser or not, made no difference whatsoever. If I re-routed the condensed flow into the intake, the leakage would go down, but the intake would be wet. If I routed the flow to the ground, the intake would be dry, but the leakage would increase.

I put new valve stem seals in. This dropped oil consumtion by about half for about 2 months, and then it rapidly crept back up again.

I finally accepted the fact that the engine had over 400,000 on it. It had been rode hard and put away wet, rebuilt and blown a few times, and was just (heads especially) worn out.

So,....

"That's all I have to say about that"

My .02

Zigg

 

[RLDSL]

You will find CDR type gadgets on a lot of engines other than IH /Ford. There's a bunch of Cats and others running around with them ( I picked through a big truck wrecking yard one day trying to rig an oil trap for one of my diesel cars and noticed the breather setups on all of them , I wound up scrounging an oil trap from a Isuzu NPR, it actually worked nicely for cutting oil consumption on that vehicle) one of the main reasons for the diaphram in the things is to prevent excess oil from getting sucked in at high rpms ( which is why they close at high rpms ) to prevent a runaway. If you get a diesel wound up tight and an open breather starts sucking down a belly full of oil, you've got a runaway on your hands ( just ask all the folks with the early VW diesels who took a wild ride before the recall , they had to modify the crancase breather to prevent that)
The CDR will prevent that from happening, as an aside, it will keep excess oil spray from being inhaled at high rpms, but it won't make any difference at lower rpms.

Personal driving styles could have a lot to do with whether or not folks see a difference in oil consumption between running a good one or a leaky one.

------Robert

 

[sle2115]

but they borred out the rear two cylinders to help the engine burn it thus proving that they knew that is where the oil was going to go.

Do you have factual data that supports that somewhere? I have all kinds of engine machining manual access and just for ***** and giggles, I went through all of them. Keep in mind, these are manuals that cost mucho dinero, not one of them says anything about this. Is this just a belief, or something that has been verified more than a couple of times. Cylinders do wear.

Also, as I said, I have watched smoke streamed through an intake for hours on end and modified intakes to make the smoke flow change. The air at the bottom of a 5 1/8 in air intake is more turbulent than a hurricane. So I will buy that gravity will, from forward motion or engine tilting rearward etc. will cause oil to generally move to the rear of the engine, but theory will not overcome experience in proving that the airflow causes it. I guess this horse is on it's last legs though and I am done beating it. As I said, I will take results over theory any day of the week.

So I guess as Zigg said, "that's all I have to say about that as well!"

 

[zigg]

.

So I guess as Zigg said, "that's all I have to say about that as well!"

Damn I love this site!!!

 

[dieselviznince]

Still wondering if I should mess with mime or not, I have a lot of blowby and a quart of oil about every 100 to 150 miles. But I did find the cdr just have not touched it.

 

[riotwarrior]

No the CDR is not likely the cause of excess oil consumption.

More than likely it is a cause of things wearing out. Rings, seal, valve guides.

If you want to you can us a RDT to test for change.

 

[RLDSL]

Still wondering if I should mess with mime or not, I have a lot of blowby and a quart of oil about every 100 to 150 miles. But I did find the cdr just have not touched it.

The CDR isn't going to cause it to eat that much oil.
That kind of oil consumption is mechanical. most likely Either bum valve guides, worn out rings or, with any luck at all , sticky rings. Try running some cleaner through the crankcase before resorting to surgery. I've had a few old diesels that I've revived from that kind of oil consumption with Auto RX
Unfortunately, my old 7.3 engine wasn't one of them ( it did bring a few of the really bad holes up a couple hundred PSI on compression, but the #4 oil ring wouldn't unstick for anything and I still had to tear it out) But at the very least, you'll have a nice clean engine inside if you do have to go in, and that will save a LOT of cleanup work during a rebuild.

-------Robert

 

[Cheaper Jeeper]

The CDR isn't going to cause it to eat that much oil.
That kind of oil consumption is mechanical. most likely Either bum valve guides, worn out rings or, with any luck at all , sticky rings. Try running some cleaner through the crankcase before resorting to surgery. I've had a few old diesels that I've revived from that kind of oil consumption with Auto RX
Unfortunately, my old 7.3 engine wasn't one of them ( it did bring a few of the really bad holes up a couple hundred PSI on compression, but the #4 oil ring wouldn't unstick for anything and I still had to tear it out) But at the very least, you'll have a nice clean engine inside if you do have to go in, and that will save a LOT of cleanup work during a rebuild.

-------Robert

Well, my turbo-ed truck is sucking down about a quart every 200 miles,. My main concern is that the oil vapor can't be very good for the turbo. So I've come up with a very simple, inexpensive, and non-restrictive oil trap that I'm going to try, just for giggles.

Rather than actually filtering the oil out, it will remove it by blowing the incoming vapors against a plate to condense the oil out of it. It is going to be installed in the hose between the filler neck adapter and the CDR mounted on the side of the air filter, just to see how much oil I can condense out of the stream of blowby vapors.

I also plan on giving this Auto Rx stuff a try since I've seen it recommended by a couple of different people on a couple of different sites now. It will be interesting to see how much oil I can condense out of the blowby gasses both before AND after the Auto Rx treatment....