Since Forrest's major mods round 2 all has been going well-very well in fact. The power is outstanding as is hot/cold starting and overall running. Forrest has never run better. I've been trying some different custom tunes and have landed on PHP custom tunes being the favored variety.

Within the "major mods round 2" thread, I made an effort to try routing CCV outside of the intake tube-pretty much for the helluvit. I was indifferent to the various reasoning's both for and against the modification and I thought I'd try a few things to see if I could effectively route the CCV externally and not have the oil mist running through the cold air side of the turbo system. During this work, I removed the IC and cleaned it out. There honestly wasn't that much to clean after 165K but I thought I'd give it a try. I first used a breather tank:




It fit and looked pretty good but didn't work out for a few reasons. 1) Path of least resistance was through the filter on top after going through the tank and once the filter on top the tank became oil saturated, it created back-pressure and Forrest protested by smoking out the tail pipe under boost. It could be that the baffling was insufficient, but not likely IMO. 2) the breather made Forrest rather stinky at idle in the cab-duh... Driving was no issue but idling sure was. 3) the oil saturated filter started dripping... OCD took over with this information and now the tank is at the Portland swap meet this weekend.

My next venture was to perform the "classic" CCV mod by routing 3/4" fuel hose over the brake booster and routing under the truck to about the transfer case. Forrest was pleased with the back pressure being under control and stopped smoking out the tailpipe when under boost. For a few days I thought this would be a reasonable solution. After those few days passed, I found that I could smell the fumes and see them occasionally when sitting at stop lights if the wind was working in that direction. I thought about extending the hose out further but two things precluded that. 1) Backpressure in the crankcase is no good and extending the hose will increase that. Slightly albeit 2) I didn't want to buy more 3/4" hose and 3) I already decided I need to route back to the intake.

The current and last iteration of CCV Re-Route is leaving the doghouse reversed, routing 3/4" fuel hose up and curved over the brake booster, then around to the 4" steel coupler between the intake tube and the 4" turbo tube on the 38R. I drilled a hole, welded in a 1/2" NPT mild steel bung, threaded a brass 3/4" barb and made the connection.











Pluses are there is no more stinky going on, back pressure is minimized and perhaps even a little negative back pressure is created as the turbo spools up, the hose going up over the brake booster may reduce oil reaching to the intake and drain back into the valve cover, the 4" coupler is less restrictive than the stock coupler. Lastly, without the metal bracket, the intake tube arrangement is less rigid in terms of managing flex and letting the 38R tube establish it's own "happy path" vs being contorted to fit.

My final thoughts on the subject of CCV re-route:
1) Leave the CCV as is-it's not going to cause any problems per se
2) Go classic if you're fine with the fumes
3) Build a more complex CCV filtration system using an electric vacuum pump to minimize back pressure and even create a little negative back pressure
4) The option I went with here seems like a good alternative to the stock setup.

 

Do you have a more straight on shot of the hose? I would like to see where it goes after being routed over the brake booster. It appears to dip down a bit which would theoretically cause a p-trap of sorts over time right? If so, this would increase pressure greatly, unless I am understanding the mod wrong.

All you ended up with pretty much is the dog house reversed and a longer tube to the intake instead of the very short OEM tube. This is an interesting method that I had not seen before. This method still gets rid of the fumes, coats the wheel and turbo with a bit of oil and protecting it from the elements and still maintaining good pressure out of the vent.

 

Ever thought about sending it into the down pipe? If you had an acute entry angle, you'd get a little venture suction out of it and might seal the rings better.

 

I'm afraid with no way to drain it that your hose will eventually "fill-up" & block the path back to your intake. When I have forgotten to drain my catch can the pressure in the crankcase causes the oil to blow past the rear seal & make a helluva mess, not knocking you just sharing my experience lol

 

I build my own, out of pvc and capable of holding 2.5 qts and have a drain valve at the bottom of the driver side door and can have an open ccv or closed system.

 

That's why I'm thinking if this is such a problem, then you could come down at a 45 degree angle from the back of the engine into the down pipe and anything that was still liquid would end up burnt out by the exhaust or the vapor would end up going out the tailpipe.


You'd need to use some kind of high temp hose for the initial connection at the down pipe or just make the metal tube long enough it's not an issue.

Too close to 45 from the exhaust's bore might end up pumping backpressure into the case, and we all know that's bad. Maybe a check valve in line?

 

FWIW, dumping into the exhaust on a diesel is a no-go. I won't go into all the research around this but it's been tried and fails as a solution.

Now, the low point in the hose is a good call out. I don't think there's that much liquid pumping through the CCV to really be an issue with the "p trap" concern as evidenced by the lack of oil in the intercooler when I drained it, but nonetheless, I also saw that as a way to further simplify the design and shorten the hose a bit. The next improvement is the installation of a -12AN fitting into the bung and on the hose to facilitate an easy removal as the brass barb is very unwilling to let go of the hose. Those pieces are coming. So far, I'm happy with this approach. It simplifies the intake tubing by eliminating the bracket, is less restrictive than the factory inlet connector and promotes less oil getting into the intake via the hose heading up for a longer stretch before going to the intake.

 

looking good there SRBF, wish I had the ability to fab that up as I would jump right on that! looks very clean too!!

 

The latest version of the mod seems to be the most logical and cleanest.

Good work, I may follow your lead on this if/when I get back in there for more mods and maintenance.

 

Got any links? I'm not saying to feed it into the turbo, I'm saying to feed it into the tailpipe with appropriate geometry to cause a vacuum on the tube.

Guys used to put the tubes cut at 45 degrees down their firewalls to have the air flowing under the car pull vacuum on their crankcases in the 60's and 70's.

 

That's simply an old wives tale. I put 150,000 trouble free miles on mine routed to the exhaust. It's the best way to run it IMO.

 

That being the case, it's probably in the same category of the benefits of CCV routing being widely ranging debate and mostly a personal decision. Thanks for sharing your experience! I'm going to stick with this version as going further is more trial/error and I don't see potential gains worth the effort as even left as delivered, trucks go to 1MM miles or 200K miles-many more variables affect lifetime.

 

Final iteration includes AN fittings:

 

The oil is still going to get sucked in, regardless wich angle its orienteded. Ill take pics of my system tomorow. Or check it on my thread "ebay catch can"(phone and cant link stuff)

 

I built this one a few years ago and it's worked great although I've barely drained a couple ounces out of it in that time. I mounted it on the frame rail next to my fuel filter. I used transmission line as I heard from some folks that heater hose will disintegrate eventually from the oil and bits will be sucked into the system. It routes the air right back into the doghouse after passing thru the cannister. No smoke or stink or drip.

That reminds me I do need to open that CCV can and check the plastic scrubbers I put in there to make sure they are not disintegrating.