Crankcase ventilation hose goes nowhere?

[jetjock]

I recently bought a bobcat 853. I have noticed that there appears to be a crankcase venalation hose attached to the side of the top of the crankcase but the hose end is not attached to anything. Is that normal fior this model? When the engine is running I get some obvious exhaust out of the end of the hose.

 

[OldMachinist]

Thats standard on a Kubota engine. It should come off the valve cover and run almost all the way down the side of the engine.

 

[skidsteer.ca]

Thats standard on a Kubota engine. It should come off the valve cover and run almost all the way down the side of the engine.

That is standard on the Isuzu engine in the 853 as well. Air escaping out this pipe is what is leaking past the pistons in the engine. There will always be some piston blowby but less is better then more. Blowby is a percentage of your compression escaping.
Ken

 

[jetjock]

That is standard on the Isuzu engine in the 853 as well. Air escaping out this pipe is what is leaking past the pistons in the engine. There will always be some piston blowby but less is better then more. Blowby is a percentage of your compression escaping.
Ken

Okay, thanks for the responses. It just seems strange to have this hose just hangin there. I have always been used to seeing some sort of pcv system in a auto engine where the hoses actually go somewhere.

 

[Jyuma]

Okay, thanks for the responses. It just seems strange to have this hose just hangin there. I have always been used to seeing some sort of pcv system in a auto engine where the hoses actually go somewhere.

Back in the day, our car engines had what were called "road draft tubes". They were mostly candy-cane shaped metallic tubes that stuck into a grommet someplace at the top of the engine and arced away and down for the dual purpose of venting the crankcase gases to the outside world and prohibiting pressure buildup inside the crankcase that could possibly cause oil seepage past the seals. The crankcase affluence was channeled directly at the road via a sleight vacuum, or "draft", caused by air passing over the open end of the tube (Bernoulli's principle) positioned under the car... thus the name "Road Draft Tube".
In a fit of ecological insanity there came a time when venting crankcase gases to the outside world fell on disfavor so they applied the crankcase ventilation equivalent of sweeping the dirt under the rug and the PCV valve for the automobile was born.
The efficacy of a PCV valve is a subject of considerable debate but it did affect at least one notable accomplishment... it masked minor blow-by issues.

 

[jetjock]

Back in the day, our car engines had what were called "road draft tubes". They were mostly candy-cane shaped metallic tubes that stuck into a grommet someplace at the top of the engine and arced away and down for the dual purpose of venting the crankcase gases to the outside world and prohibiting pressure buildup inside the crankcase that could possibly cause oil seepage past the seals. The crankcase affluence was channeled directly at the road via a sleight vacuum, or "draft", caused by air passing over the open end of the tube (Bernoulli's principle) positioned under the car... thus the name "Road Draft Tube".
In a fit of ecological insanity there came a time when venting crankcase gases to the outside world fell on disfavor so they applied the crankcase ventilation equivalent of sweeping the dirt under the rug and the PCV valve for the automobile was born.
The efficacy of a PCV valve is a subject of considerable debate but it did affect at least one notable accomplishment... it masked minor blow-by issues.

It seems that I am having a lot of blow by. I actually stopped the machine the other day because I thought there was possibly a fire in the engine compartment. It turned out to be just the smoke coming out of the tube. Wondering if anybody has ever funneled this tube back into the air intake once past the air filters. I realize you would not want to do it before the filters because there would be enough to eventually gunk them up. BTW - it doesn't seem to be burning an excessive amount of oil - based on the age of the machine. Thoughts?

 

[Tazza]

It seems that I am having a lot of blow by. I actually stopped the machine the other day because I thought there was possibly a fire in the engine compartment. It turned out to be just the smoke coming out of the tube. Wondering if anybody has ever funneled this tube back into the air intake once past the air filters. I realize you would not want to do it before the filters because there would be enough to eventually gunk them up. BTW - it doesn't seem to be burning an excessive amount of oil - based on the age of the machine. Thoughts?

I have had a machine like this, i just plumbed it in just before the inlet manifold. It will just lubricate the inlet valve stems as its a mixture of exhaust and oil.