gomerpile

with all this talk lately about improved blowby breathers, i have been wonderin, why does no one just hook a tube to the intake to put a vacuum on the crankcase, also it might help MPG's. i mean you could put something like a valve on it so it dont just suck fumes out of it when you shut off the fuel.

i mean at the filter your probably pulling some good vac #'s. just wondering what migjt happen if you did do this

Richie O

In a boat I used to have with a T6-354M perkins I put the blow by hose in the suction side of the turbo Screen. On a boat there sometimes is no air cleaner. I also put in a Tee fitting in the line incase there was a restriction in the intake for the turbo. I didn't want the screen to plug then start eating engine oil and turn 4 grand. Worked fine for that.

BC847

With all the vents I have on my mess, there's next to nothing in the way of oil carry-over. With that, I'm mulling the notion of venting it into the air filter box.

BearKiller

The old Ford/International V-8 IDI diesels HAD PCV-valves that dumped into the breather, just like on old gas-burners.

All I ever seen it good for was to make a nasty pond of oil in the breather.


Nearly all of those guys have changed over to what they call a "road draft tube", which is no more than what we already have.

Some have incorporated a catch-bottle at the hose-end that has to be dumped occassionally.

olddodgetrucks

diesel has no vacuum so no pcv like a gas motor

BearKiller

I never put a vacuum-gauge on a non-turbo diesel intake, but there would have to be a vacuum of sorts created by the suction of the pistons drawing in the intake-air.

On the other hand, diesels have no throttle-plate/carburetor to close off the intake and maintain the vacuum that they create.

Of course on a turbo-equipped engine, any vacuum is quickly purged and over-ridden by the pressure created by the turbo.



I wonder if true fuel-injected gas-burners are comparable to diesels as far as vacuum is concerned.

99globalwarmer

ferd delete that because it eats up the compressor wheels and also my 680 hp 6.0 with the factory ccv valve would fill up the intake with oil gunk. the compressor wheel soon was covered in charred oil slime and threw the wheel out to of balance and caused it to scrape the compressor housing. that was before twins so i would suggest you dont ventilate any oil substance into the turbo dump it into the open or a oil water air seperator like we do to the fords that come into the shop. by the way sold the excursion to my dad. happy to get rid of it

gomerpile

yes i do agree thats theres no vacuum on the intake manifold of the engine, but there is one on the intake pre turbo, i have seen many guys with enought vacuum there that when they go full loud pedal they can completly pull down a filter minder, also when your pushing enough air to make 30 lbs of boost your pulling a hefty vacuum somewhere, also that will mainly come into play when you have boost creating blow by which is the main function of all this

wannadiesel

GM, Ford and Mercedes turbodiesels all do what you describe. Like Bearkiller said, it makes an oily mess in there. The oil cokes in the passages and on the back of the intake valves and chokes off the airflow over time. If you want to do it, you need a CDR (crankcase depression regulator) valve from a Ford or GM application plumbed in the line from the breather tube to the intake. The CDR valve limits the vacuum you pull on the crankcase so you don't suck gaskets into the engine and start an oil leak.