I have an 84 E350 with an 89 7.3 IDI. In stock form the entire crankcase vent system is just a few inches long; out of the valley cover, turn forward into the intake, done. Unless the system leaks you have no idea how much oil and gasses are being recycled.

I just added a turbo. I have a 2001 7.3 PSD. The engine is the same size, and I like the V band fittings, so I had a local shop build me a good version of a 2001 PSD turbo.

That meant relocating the Crankcase Depression Regulator. The plumbing from the valley to the regulator is about eight inches. At first I had a hose from the regulator to the outside of the frame under the driver's side door. Then what was exiting the crankcase was very obvious. It was a very small amount of oil, substantial gases flow, and grey smoke. The smoke is there both at start up and after warm. I added a draft fitting in the tail pipe about five feet from the end in the hope that the grey smoke would be diluted by the exhaust enough to not be noticeable. Now instead of the smoke rolling out from under the van in whatever way the wind is blowing it comes out the exhaust.

I can run the vent into the intake and presumably get rid of the smoke. But my concern is; how much blow-by is too much? Probably only those who have run just a draft pipe have any idea how much blow-by they have, so they probably constitute my entire survey.

In the original system, the gasses from the crankcase are under positive pressure. The fresh air being pulled in is at negative pressure. Therefore, the crankcase gasses always are "first in line", and displace fresh air. The crankcase gasses are oxygen depleted, and causes there to be less oxygen for the fuel to combine with. In anticipation of the turbo, I bought a turbo IP. I was carrying it as a spare. Well, the turbo got delayed, and two years ago, while on the other side of the Country, I had problems and installed it. That seemed to increase the soot some. I do not yet have the compressor plumbing sealed and am getting very little boost. But stopping the crankcase gasses from being recycled has reduced and maybe eliminated the soot.

 

I suspect 'too much' depends heavily on how much oil you are content with losing, and/or whether or not enough leaks by to reduce your compression below where it will start.

My own engine is fairly worn, and it has a /ton/ of blowby. My own Banks turbo came with a mount for the CDR on the intake side of the turbo, but between that and the new location for where the vapors exit the engine -- right at the front, from an adapter on the IP gear front plate -- meant that I was pulling in quite a bit of oil with my vapors... which would fall to the bottom of the air stream, and leak slowly out the connection tube between the pressure side of my turbo and the hose connecting it to the engine intake... meaning that the back of the engine became covered in oil.

I have ended up building a large oil separator can(6" tall, 4" PVC pipe, divider down the middle with holes near the bottom, entrance and exit are near the top), with a little drain tube in the bottom leading to a bottle.
With that setup, I've 'recovered' a good 8oz of oil in just a few hundred miles, and things are quite a bit dryer.

I would suggest doing something similar, both to recover oil and then burn the rest -- keeps things from dripping, and puts those oil-soaked vapors to good use!

 

International engines were designed with a "balanced pressure" piston and ring design, incorporating a large second ring gap, cut back top land, and accumulator volumes tn the second land. There are patents on this concept.

The concept keeps hinterland gas pressures low so the intermediate ring seats on the bottom grove to control oil and minimize ring groove pounding and side wear. The cutback top land allows gas pressure to help load the ring pack, and minimizes carbon loading and prevents subsequent bore polishing.

One byproduct of this design is higher blow by than some lower tech designs, which causes alarm to those not familiar with the concept.

International developed tools (calibrated orifice) and specs to measure crankcase pressure. The info should be in the service manual.

A side note: 99.9%of the car valves that have been replaced in the 30 years since the engine went into production have nothing wrong with them. Owners just didn't understand the design or function of the power cylinder/car systems.

 

That's good info there.

 

[quote=Macrobb;14438905]I suspect 'too much' depends heavily on how much oil you are content with losing, and/or whether or not enough leaks by to reduce your compression below where it will start.

In it's stock condition it did not use enough oil to hardly notice; I only checked it every thousand miles or so. It starts OK and runs smooth. I was concerned that the smoke might indicate excess wear even tho it was not using oil.

My concern now is what to do about the visable smoke. When the crankcase was being recycled the exhaust never showed smoke, just soot under high load and low RPM. I would let it keep going out the exhaust, but that is not being "responsible", and in CA we have "we tip for smog".

 

if you had put that road draft tube on the engine when it was brand new, you would be saying the same thing.
when you add a turbo the CDR gets remounted and plumbed into the intake.
on the banks unit it is re routed to the air intake with and draws off the timing cover opposite the injector pump .

 

Finn, that's interesting information, but I don't get what you're saying here. Can you please explain this:

Yup, that's very true.
Mind you, I think Banks made a bit of a mistake when they pulled it off the timing cover; at higher RPMs, those gears should be spinning quite quickly, throwing little oil droplets right into the gas stream.
At least, that's what I've seen, which was why I added a separator.

Do note that the Banks kit is the only one I know of which uses the timing cover for that; the stock ATS kit uses the driver's side head cover, for instance.
.

 

in stock form when the cdr is operating correctly one can remove the oil fill on front cover and no gases will escape, at idle hot. on my E350

 

The auto spell feature on this tablet makes posting coherent thoughts difficult. It corrects "cdr" to "car", among other things.

The cdr valve is bulletproof, but many were replaced back in the day erroneously because of concern with oil carryover in the intake.

As long as the engine starts ok, the power cylinder is probably still good. (Hard starting is not a conclusive sign that the rings are worn, though, as other things can also cause hard starting.)

International truck applications had a valve cover mounted cdr valve, if I remember correctly.

 

It originally vented from the valley cover and I saw no need to vent it from anywhere else. It just took a few inches of plumbing to get be able to turn it around. The shop that did my turbo used to do kits and they just turned it around without moving it. But that puts a strain on the valley connection.

 

my banks kit has been on my truck for 490,000 miles, and i never had any problems with oil slinging off the timing gears into the CDR tube.
i had to change the stock CDR at around 300,000 miles because the diaphragm failed.

 

A diaphragm moves. How does one test a CDR? I don't think mine has any moving parts. As part of a cleaning process I ran water thru it both ways, freely, without pressure.

 

mine was easy to tell it was bad, there were pieces of rubber in the air intake.

 

That's normal, there is a diaphragm and spring inside, the default position is 'open'. See the small 1/8-ish hole on the back side? Blow into that with your mouth, if you use compressed air you will kill it, and while blowing you can feel with your finger the diaphragm moving against the spring. (If it's working right of course.)

 

Here's some more poop: