another blow by question (1 Viewer)

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update....

with the valve cover vented directly to atmosphere my oil leakage has nearly completely stopped. i don't have any more puddles on the drive way and the side of my engine is still relatively clean. ill likely just get a length of hose and keep it vented that way and forget the catch can all together. i guess the pressurized crankcase would likely prevent the oil from draining back in so there was excess oil in the valve cover causing the excess spill over. that's the only way i can make sense of less oil
coming out while venting the hole more that the oil comes out of!! anyway lesson for those wanting a catch can... make sure it flows enough air
 
@franklin40 What were you using for a catchcan that proved to be too restrictive?
 
Yes, I'm interested as well. I was originally getting blow-by with the factory setup (i.e. the valve cover port outlet is connected to the post-filter/pre-turbo hose). I knew this because the hose connecting from post air filter to pre turbo was saturated with oil and would drip on the ground.

To fix this I installed a Provent 200 in my 1HD-T. Since installing the Provent the oil that used to saturate the hose that connects the air filter to the turbo intake is gone (doesn't drip and doesn't appear "wet" with oil), but I'm definitely still catching blow-by oil using the Provent 200. Not that much oil, but enough that I notice there is oil accumulating at the drain port (I have a clear, plastic hose going from the bottom of the Provent to the wheelwell where I have a stopcock drain valve that I can use to empty it).
 
I remember someone who ran the vent hose into his frame rail and used the pressure to keep the frame rust free!

Glad you found the problem and it made it better.
 
i was using a mishimoto baffled catch can. i have some blow by still but very little oil coming out the valve cover. when the engine was installed there was just a little breather filter that was getting saturated in oil so i took it off and put a catch can on. i don't have the stock air cleaner so the hose wasn't routed to burn the vapours. just vented to atmosphere. i wonder if the breather was a little too restrictive as well. right now i have the hole on the valve cover completely open (i don't want it to stay this way though). i don't seem to have any oil drops now. i wonder if the negative pressure that the air intake creates helps that much? even a small restriction seemed to increase oil output. when i get my new air filter system going i might try a provent and then route it back to the intake. or maybe ill just leave it with a hose into my frame. time will tell
 
Personally, I don't want to have any engine blow-by being fed into my engine. My Isuzu is also a turbo engine, and having oily mist coat the blades and heat soak bake it it not something I want.

My engine has the factory crankcase oil separator that drains any oil back into the oil pan, but vents to the atmosphere.
 
after about 100km of driving both highway and city boosting up to about 12psi my engine looks like this. i washed it just before. night and day difference. it's super clean now. i also took the catch can right off. was just disconnected before. i bought some hose to just vent it down for now. just haven't put it on yet
IMG_4359.JPG
 
I had the same problem with my 12ht sucking oil into the turbo inlet it only happened when working the engine hard pulling my caravan. I installed the provent 200 per there fitting guide and had great success with no oil entering the induction side. The manual states the filter should be replaced every couple years my guess is the OP filter is blocked and needs replacing.
The moral of this story is when all else fails read the destructions :)
 
mine didn't have a filter. just a baffled catch can that i think didn't flow enough volume. the breather was also covered in oil which would also then make the air flow worse. no blocks in the system. just not enough air flow to allow pressure out

after a few hundred more km there is a small oil drip under the valve cover vent. ill keep an eye on how much a mess it makes. may still look into a provent
 
Personally, I don't want to have any engine blow-by being fed into my engine. My Isuzu is also a turbo engine, and having oily mist coat the blades and heat soak bake it it not something I want.

My engine has the factory crankcase oil separator that drains any oil back into the oil pan, but vents to the atmosphere.

Can something like this be used on a turbo 3b?
 
Can something like this be used on a turbo 3b?

Just cut the breather tube down a bit and get some one inch I believe oil/fuel rubber line. slip it on the shortened breather tube with a hose clamp. put the other end into your frame. It the best thing you can do for half your frame here in Canada.
 
That is true but I don’t see the vent tube or any part in the motor getting corroded from it. Seems like even the exhaust rusts mostly from the outside. The oil and oil vapor overcomes any acidic properties.
 
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I use Eastwood internal frame coating on mine with great results and ran my blowby tube to a Venturi at the end of my exhaust. No more smell in the cab at stop signs, better ring seal from crankcase Vacume and the frame is well protected from internal rust. A nice bennifit too is many of my small engine leaks stopped.

image.jpeg
 
Measuring crankcase pressure under operation has to go on my to do list. I think we underestimate both the pressure and volume when we're driving and are satisfied to watch it gently puff out at idle in the driveway. Or maybe at least I do.
 
Quick question for you guys... I rigged my crank breather with a hose down to the frame. It works perfectly but I feel funny about leaving it open. Do you guys just leave the hose open? Or do you use a filter or something similar?
 
Open. on my 3b’s it’s just a pipe pointing at the ground open from the factory. Filters would get plugged real fast and cause pressure problems.
 
Open. on my 3b’s it’s just a pipe pointing at the ground open from the factory. Filters would get plugged real fast and cause pressure problems.

Thanks for the reply. So, this setup would be ok to run permanently?



 

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