Crank case vacuum

R

roost

New member
Is there gains to be had adding vacuum to the crankcase? I know it can work well on higher hp gassers, why not cummins?
 
I run an evacuation setup on my drag truck plumbed into the hood stack. Its benefit is I don't have to strap down the dipstick tube and was constantly pushing the tapper cover gasket out before.

Now this is a drag truck only and has worked perfect for me, some other guys have tried it on hot street trucks with mixed results, some have said it will suck oil out the exhaust.

On my drag truck it's been working perfect with no oil out the stack, and it doesn't half fill my catch cans anymore.
 
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Interesting. So gas velocity pulls blowby from the crankcase if I understand that correctly.

Ive seen dyno results of +100hp on healthy big blocks running a belt driven vacuum. Maybe it's alot less significant with diesels.
 
Has anyone tried this? Wouldn’t be hard to toss an AN line from a lot the valve cover into the exhaust


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I've had plans of pulling it through a parker oil separator into the intake on my cat. Haven't done it yet though. I think it would help with oil leaks more than anything.

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chevota84 said:
I've had plans of pulling it through a parker oil separator into the intake on my cat. Haven't done it yet though. I think it would help with oil leaks more than anything.

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Why not just vent to atmosphere instead of adding a more complex system?

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jasonc said:
Yes I have, works well for me.
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You ever gonna post anything on your truck? Got a YouTube or something? Been interested in seeing some details or video on it for a while now.


As for vacuum on the crankcase making power, I’m guessing these high compression diesels just aren’t effected by the windage as much. Also guessing the rings have more tension than a gas engine and revs are generally lower than a gas engine. That’s just my uneducated guess.
 
bateman said:
You ever gonna post anything on your truck? Got a YouTube or something? Been interested in seeing some details or video on it for a while now.


As for vacuum on the crankcase making power, I’m guessing these high compression diesels just aren’t effected by the windage as much. Also guessing the rings have more tension than a gas engine and revs are generally lower than a gas engine. That’s just my uneducated guess.
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I'm not much if any on social media, the trucks been sitting in my shop for the last yr covered in dust. I keep saying I'm gonna get it out and back going, maybe this fall.

Our local track shut down and I kinda lost interest.
 
Before I added the evac setup to the hoodstack, the 2 catch cans would have about a half quart in them, and I also had to strap the dip stick down or I would push out and spray oil mist.

All that went away after plumbing in a single vent hose to the stack, along with keeping the additional 2 separate vented catch cans.
 
bateman said:
You ever gonna post anything on your truck? Got a YouTube or something? Been interested in seeing some details or video on it for a while now.
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jasonc said:
Before I added the evac setup to the hoodstack, the 2 catch cans would have about a half quart in them, and I also had to strap the dip stick down or I would push out and spray oil mist.
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You don't really have a race truck. It's all bullshit isn't it? JK :bow:
 
Couple years ago I went through his post digging to see if I could get some details on it haha Just interesting setup what little I’ve heard about it.

I ran a vibrant exhaust evac on a little 600hp 4 cylinder when I was a kid. Pretty much in a stack the stack was just pointed at the ground. Seemed to do its job.
 
bateman said:
Couple years ago I went through his post digging to see if I could get some details on it haha Just interesting setup what little I’ve heard about it.
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Jason is a good dude, and he knows lot's of things about the diesels for sure. I'm just messin'.
 
bateman said:
He seems like a good ole boy. He had my attention when he posted his Cummins boat haha
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While we're in derail mode, why did I think you lived near Lake Havasu Az.?
Do I have you mixed up with someone else? I'm sorry, but I'll just use my age as an excuse if I am wrong.
 
Haha not me. I’m just a honky from Alabama. I’ll let it slide this time.

I have been to AZ once if it makes ya feel any better.
 
I did this back when plumbed into the downpipe. Worked well. I would smell a little oil burning after a hard pull, but never saw any wetness or anything. I did away with it after going to a hoodstack.
 
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