how to reduce crank case pressure

jordanjames81

jordanjames81

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whats the thoughts of making a system to pull the pressure out. I know gasser guys do it with on dragsters in seen it on some pulling truck. Wonder how it would work on a diesel tie in to the down pipe. Put a vent in the valve cover then run tubing to exhaust with one way check valve so soot dont get in the engine.
 
im not so sure that it would work on a turbo motor.. it smoothes out the pulses im thinking and the pulses are what i assume pulls out the cc pressure on gassers and usually it seems like those motors are cammed pretty big also.. i might be outa my tree and you are on to something but i dont know for sure.. i just spent 10 bucks at napa auto for some heater hose and pcv grommets and drilled to of my valve covers, oh and the oil filler too.. should be pretty vented..
 
Lazer Smith does a vacuum pump on a pully system for the CR. One of the theory's in that system is your pulling a negitive on your crankcase to reduce blow by. Putting a check valve in the system IMO would not work. It would be very hard to pop open at 1/2a psi unless you have some serious ring, valve or piston issues. It would then gum up and not work for chit if you managed to build enough pressure to release open it. Just use the breather kits you can buy at summit jegs etc. Thats what I did worked great and evey now and then open the drains on them and get the excess oil out.

I hear you on venting works good on mine. Just do it to atmosphere instead of trying to get it in the exhaust.

Chris.
 
i took all the filters off of my CR two years ago when built engine. Put in some Jci fitting and some blue hose over to driver side in tied the vent off the block into it. Just looking for a little different set up, I eighter need longer hose or keep cleaning front diff off.
 
jordanjames81 said:
whats the thoughts of making a system to pull the pressure out. I know gasser guys do it with on dragsters in seen it on some pulling truck. Wonder how it would work on a diesel tie in to the down pipe. Put a vent in the valve cover then run tubing to exhaust with one way check valve so soot dont get in the engine.
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You watched TRUCKS on spike TV today, didn't you.
 
I spin the 350 in my toyota to around 7500 and I kept pushing valve cover gaskets out. I ran a 3/4 in hose from a baffle in the valve cover to the intake, no more oil leaks. Running one pre turbo would have to go through a pretty good baffle or you'd pull oil I think.

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i bought a vacuum pump, but i cant find a pulley to fit and im not sire where to mount it.
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remind me to never go to carbon county. i feel i will get dumber if i was to visit
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hummin cummins said:
You watched TRUCKS on spike TV today, didn't you.
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I thought about this a two years ago when i built my engine. I have a cousin that run a big block chevy with a blower running this set up. Thought about trying it but never did, and today on trucks i seen it again. I think it would work if the turbine side on charger in down pipe didnt act like a pump in suck the oil out the engine. Guess you could run a vacum gauge in the cab to keep a check on things
 
I understand it's not quite the same animal but every gas engined vehicle I have owned had a crankcase breather hose plumbed into the air intake.

Why not do something similar and put it pre-turbo? You could put a restrictor in it to keep it from pulling oil?
 
I can't speak for the OP, but the amount of residual oil I have from the blowby is excessive, it was before the rebuild at HIGH RPM, but now it's leaving puddles if I make anything over 10psi then park it (could be because it's a fresh motor). However, I'd like to fix my issue before I get back to turning the RPM I used to.
 
if your filling the block with pressure the pison is working on the down stroke in, so it pulling double duty, If you can take that away then it free things up mean less fritcon in my opinon.

with the check valve it opens from crank case pressure and the exhaust make a vacum to help get it out.
 
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The 2007 & 2008 Jeep Grand Cherokee Diesels have the crank case breather tied in about 2" before the turbo on the intake pipe.

I image the vacuum created by the turbo helps to vent the crank case gasses.

As far as oil consumption, even with the tight Mercedes 3.0 V6 CRD Motor, the intake tract, turbo, charge piping, charge air cooler, and heads all have an oily mess from this system. In fact, it commonly pools oil and leaks at the turbo inlet boot and causes other issues and damage to electrical components directly below the turbo.

A common "mod" is to eliminate the closed crank case ventilation and run a catch can or draft tube down by the frame rail.

In a racing application, tying in the breather pre-turbo might be a good thing as long as it doesn't pull enough oil to cause a run-away condition.
 
Hellman, or somebody makes a big, nice crankcase breather canister. I'm wondering if you could install one of those, but also put another nipple coming off the canister that ties into your intake tube. So when ur at idle and low rpms, the vapors exit thru the filter on top, but at high boost, high rpm's, there's a small amount of vacuum pulled on the can.........................Make any sense?
 
but without a 'grease filter' or some type of baffle there's still a chance of drawing oil back to the intake tract.
 
diesel_importer said:
Hellman, or somebody makes a big, nice crankcase breather canister. I'm wondering if you could install one of those, but also put another nipple coming off the canister that ties into your intake tube. So when ur at idle and low rpms, the vapors exit thru the filter on top, but at high boost, high rpm's, there's a small amount of vacuum pulled on the can.........................Make any sense?
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The summit catch can with breather I have has two places to hook up, just needs another nipple. To work your way, it would need a check on the breather to develop vacuum.
 
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