RDT delete.

So, I was sick and tired if the blow by smoke at idle with a RDT.
Since I had my down pipe out, I decided to weld up a tube for a 1 way check valve
At a 60ish degree angle it will suck the crank case pressure out like a Venturi.
I run this set up on my boats to prevent oil mess since they are ran at WOT most of the time.
Gonna be pretty nice.

be ready for oil out the tail pipe. biggest complaint with doing that. a few here have tried that way and just went back to the stock setup or a catch can design.

if it gets bad, ill make a catch can inbetween the valve and CDR.
the plug in the valley pan, does that go to the lifter valley?
maybe fit it for a oil return from the can?

I'd be concerned about back pressure - you're crankcase pressure is now going to be at least somewhat above atmospheric - exhaust back pressure will be at least a bit, plus the pressure drop across the check valve. Depending on the check valve, amount of blow by, and how free flowing the exhaust is it could be significant, and it doesn't take much to start forcing oil through the seals. Most likely not a major issue, but something to think about.

Also going to have oil out the tailpipe, and likely decent smoke clouds under some conditions. Woln't reduce the amount of smoke at idle either, just make it come out the tailpipe instead of under the body.

The thing with an oil separator is that the oil drain really should be into the oil sump below the oil level. This creates a liquid seal and prevents gases from coming in the oil return. If you just duct a drain into the engine then you'll likely get blowby out that line which will suck the oil right back up again. I'm planning to build a setup using a real separator plumbed in this way, but haven't done it yet. My model is the Volvo redblock engines which use a simple baffle setup to catch oil and drain it back to the crankcase.

jaluhn83 said:

I'd be concerned about back pressure

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im running a 3" down pipe and 4" exhaust dumping out before the rearend.
like i said, ive used this process many many times with much sucess.
backpressure if any, will be kept to a minimum. on my v-drive flatbottoms, i run 1 per bank to evacuate any crank case pressure.
ive never had an issue with excessive backpressure blowing out gaskets and seals.
with the tube being at an angle, it will actualy suck the crank case pressure out, the check valve is just a fail safe.

as far as oil is concerned, i will address this further if it becomes an issue.
it did not blow much oil out when the RDT was installed, i did notice a film on the frame where the tube was secured.
but no puddles of oil, even when idling in the driveway for 30 min +

I tested quite a bit with a vacuum/pressure guage on my down tube. Same set up with a pulse air check valve that has a lighter opening rate. There wasn't enough vac. generated in the down pipe to open the checkvalve. Removing the check valve allowed pressure in the downpipe to escape. Wasn't more than a lb. but put a piece of paper over the opening and it blows it away from the inlet. I did get about 1.5 inches of Vac at 2500 rpm. Wasn't worth it to me to pressurize the crankcase. This has been discussed at length on this forum. The turbo dampens the exhaust pulses and that makes the dead "vacuum' spots between firing waves disappear. I also have a 3inch down pipe and 4 inch exhaust. Yes it works on your gassers. Take it for what its worth, its not going to work on your truck.

Dieselcrawler said:

be ready for oil out the tail pipe. biggest complaint with doing that. a few here have tried that way and just went back to the stock setup or a catch can design.

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What he said. I was planning to do this (and even have a bung welded into a piece of exhaust pipe to thread a venturi fitting into), and decided not to after others dealt with this problem. I would strongly recommend taking a look at this thread: http://www.oilburners.net/forums/showthread.php?67332-RDT-Into-Exhaust

IDIoit said:

the plug in the valley pan, does that go to the lifter valley?
maybe fit it for a oil return from the can?

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Surprisingly no, that plug in the rear of the valley pan does not not go into the lifter valley. The center of the plug is hollow...I think the purpose of the "plug" is to help hold the valley pan in and keep anything from cross-contaminating, but any liquid that goes into that hole gets dumped out the side, somewhere above the starter. I think it was IH's way of getting rid of any liquid that gets into the valley, including rainwater and fuel (in case of an IP leak) without it getting into the engine block via the CDR valve grommet.

looks like a catch can is the way to go!
altho my 7.3 does not produce much oil out of the CDR, im sure in time it will.
so if oil is the biggest problem with this design, i will run a catch can inbetween the CDR and exhaust.
im going to build my own can ill post back when i get to it.
today, i get to address my transfer selector and hopefully install new door panels and carpet.

after about 500 miles,
this is my exhaust pipe.
no significant oil in exhaust!
guess im one of the lucky ones!