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This is on my bone stock 93 NX2K. While the car is running and the oil cap is off, there is a lot of air coming out of the oil fill. I heard this was normal but want to make sure. Thanks.
It's going in as well as out. Lay a strip of paper over the hole and watch it flap.
The pistons have to push crackcase air out of the way as they go down; as they go up, they suck air underneath themselves. Since the case webs aren't drilled to allow this air movement between adjacent cylinders (there's a couple of horsepower for the rich and determined), the entire crankcase air volume is stirred up. It's easier for the pressure to exit the oil filler hole (when the cap is off) than to migrate to the nearest piston moving in the opposite direction.
Rest assured, there is a small amount of blow-by past the rings but not enough to generate a sensible air movement.
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Bruce in Houston
1990 Acura Legend LS, stock (so far)
1994 Nissan Sentra SE-R (original owner) w/ $tuff, converting to ITA (even more $tuff)
1998 Suzuki Bandit1200S w/ $tuff, W.W.B.O.C. #101
2002 Dodge Dakota tow beast, stock! RIP swwwinger
It's going in as well as out. Lay a strip of paper over the hole and watch it flap.
The pistons have to push crackcase air out of the way as they go down; as they go up, they suck air underneath themselves. Since the case webs aren't drilled to allow this air movement between adjacent cylinders (there's a couple of horsepower for the rich and determined), the entire crankcase air volume is stirred up. It's easier for the pressure to exit the oil filler hole (when the cap is off) than to migrate to the nearest piston moving in the opposite direction.
Rest assured, there is a small amount of blow-by past the rings but not enough to generate a sensible air movement.
Here's what I got from this:
So basically, what your saying is that the air is made by the pistons movement and is normal? When the air comes out it feels like it would if I had my hand over my exhaust pipe, except it is more lopey. All in all, the car idles and runs smooth, there is no ticking or rough idle. Also I have noticed that some cars don't do this, is it because their case webs are drilled so it allows air movement between the cylinders, and since SR20's aren't it helps a little with horespower??? Please tell me if I am right or way off. This is something that I am not familiar with and would be a good new thing to know.
Thanks for the helpful info, please chime in some more so I can make sure I have the right idea.
bruce....what do you mean theres some more hp for the rich and determined? how do you fix that i have like 4 blocks i can attempt some stuff if im pointed in the right direction.....and if i kill a block well ill give it a proper burrial
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1991 nx2000:Black:Wrecked:Sold
1992 nx2000:White: Sold
1993 nx2000 :Electric blue:Sold
its not who you do in life, its who you leave behind. Jerry James Hays 9/1/1982-5/14/2006 Danielle Wilson 2/10/07
If someone could please tell me a straight answer of yes or no, that my car is running how it should and nothing is messed up, it would be nice . I can't compare it to my SE-R because i'm in the middle of a DET swap. Also if what I said 2 threads above is correct. Thanks.
Yes this is normal. It is called positive crank case pressure. This is how the PCV valve (positive crankcase ventilation valve) works on your valve cover.
I would not run your car like this...
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Black B15 SE w/pp
White B15 SE w/pp
'92 NX2000 - sold
Yes this is normal. It is called positive crank case pressure. This is how the PCV valve (positive crankcase ventilation valve) works on your valve cover.
I would not run your car like this...
Why would you not run my car like this if it is normal???
bruce....what do you mean theres some more hp for the rich and determined?
Drill ports through the webbing between the cylinders. This shortens the path the air must travel from one falling piston to the nearest rising piston. Less pumping loss. It won't be much extra power but it's there nonetheless.
This is becoming common practice in new crotch rockets (but has been around quite some time). I will say it again, read the mainstream motorcycle mags that review sport bikes. They give excellent accounts of how manufacturers are squeezing every last horsepower out of those little mills. What works in a motorcycle engine works in a car engine with the caveat that motorcycles are still running lots of overlap on their cams. Well, that and every sporting engine spins to at least 11k rpm.
Jerry James Hays 9/1/1982-5/14/2006
. I can't compare it to my SE-R because i'm in the middle of a DET swap. Also if what I said 2 threads above is correct. Thanks.
