Cummins Blowby

[nate]

I'm a little cornfused here.

I got some info on another forum on how to check the blowby. Info here:

http://www.cumminsforum.com/forum/94-98-powertrain/8684-how-much-blowby.html

Well I built the manometer (took me like 5 mins) I just used a 3/4" to 1/2" adapter hooked into the blow by tube which is relocated to by the fuel tank.

I ran about 5 feet of 1/2" clear tube, put in a T Fitting. I plugged the T and then drilled a 15/64" on the side of the fitting. This is a controlled leak since otherwise the blowby would just push the water out of the manometer.

Another 6 feet of tube makes the U, which is filled about 1/2 way with water.

I fired up the truck which was still fairly warm from coming home.

At idle, the water raised 1 1/4"

At 2500 RPM, 2 9/16"

At 2800 RPM 4 1/8"


Now the info on that site says a NEW engine should be worse than those #s, so something isn't right. My truck has 182,000 miles...

Does anyone see anything wrong with the math in those numbers? I'm not sure how water column is converted to lpm.

 

[Billysgoat]

Correct, a NEW engine will be worse than that because the rings are not seated yet. These engines wear in, not out (to a point).

 

[kuntryboy369]

you gettin any oil drips out for you blowby tube?

 

[nate]

Not that I've noticed. Just a fairly steady stream of oil vapors.

I did a bunch of searching and I don't see how a person can convert inches of water column to liters per minutre.

One is a measure of presure and the other is flow. They aren't directly related to each other.

Here are some pictures of my setup...