Excessive Blow-By Kama 554

[Artrac]

Members with Yangdong powered KAMA might be able to purchase the vented oil fill cap from a Jinma parts dealer and adapt a recirculating crankase ventilation system

[3RRL]

artrac said:

Members with Yangdong powered KAMA might be able to purchase the vented oil fill cap from a Jinma parts dealer and adapt a recirculating crankase ventilation system

Chip,
Could you explain what you mean by "recirculating" system?
I am still keen to help reduce the amount of blow by coming from the stock Kama 554 vent. Is there some literature or a link to where I could read about?
Thanks,
Rob-

[FlyHiFlyLo]

Rob, just pull the valve cover off. Go to the auto parts store and buy a PCV (Positive Crankcase ventilation) valve. While you are there get a PVC valve grommet. Drill a hole in your valve cover, push the grommet in, push the pcv valve in, install a 3/8" barbed fitting into your air cleaner housing, run a 3/8" hose from your PCV valve to the air cleaner..... Run a sealed oil cap. (no breathers)

Well-ah! Instant recirculating system.

All a PCV valve is- is a check valve that prevents air from sucking back into the crank case when the pistons are on the "up-stroke"

A smog pump on cars is only a vacuum pump that sucks the air off the back side of the pistons. Many race cars run this with two large check valves on each valve cover.... This actually sucks the piston down and makes even more power. The sucked air is deposited into the header collectors with two more check valves.

[3RRL]

Scott,
That is similar to what I was considering doing by running the breather to the intake manifold via a tube. Except without the PCV valve. So essentially that "blow-by" will get sucked up into the intake, right? What about excessive carbon build up on the valves? Do you think that will be a big problem then?
Question:
- Is it necessary to run a sealed oil cap or can I use the ventilated one?
- Is the 3/8 line large enough?
Thanks

[FlyHiFlyLo]

The vacuum from the engine actually helps suck the air out of the crankcase. You have to run the PCV to keep the pistons from sucking air back into the crankcase. Must be sealed. It doesn't affect the valves. Instead of the barbed fitting you can get a PVC filter from a 80's V8 air cleaner. This prevents oil from getting sucked into the intake.... But WTF it's a diesel.

Don't worry about the valves. A PCV system helps keep the seals from leaking too...

[bracabric]

Rob, if the smoke from the outlet only becomes noticeable after hours and hours of work, sounds as if the engine is gradually getting too hot! Have you noticed if the temperature gauge gradually gets higher as the work progresses? If so maybe the radiator is clogged with dust etc.

Dick

[3RRL]

Scott, thanks for the great diagram!
I will try to get that done...sounds like an improvement to me.

Dick, no the Kama does not overheat at all.
I should clarify that once it is up to running temp it smokes through that vent a little more than when it's cold.
It's more noticeable then.
The other thing is when I'm moving, I don't notice it either, since the smoke is dispersed into the air and I drive past it.
It is NOT like a cloud of smoke though.
I only notice it after stopping and letting the tractor idle after a long workout.
That's when it becomes MOST noticeable that there is a small amount of smoke coming from that valve cover breather vent.
So perhaps it's more normal than I think?
Rob-

[baknblack]

3rrl said:

So perhaps it's more normal than I think?
Rob-

Very normal. Scotts PCV system should take care of the smoke and if you not burning more than a quart every 100 hrs your engine is in great shape. I really don't think on a diesel you actually need a check valve.

For instance:

My 7.3 liter power stroke has a significant amount of blow by at idle. It puffs out the dipstick. It has no pcv check valve. just a screen and a hose going back into the intake before the turbo. The screen catches most of the oil and lets it drip back into the valve cover, the vapor travels on to be burnt. As soon as you rev the engine a bit the turbo creates enough negative pressure to suck the gas out of the crankcase.

[3RRL]

Dwayne,
Thanks,
That's what I was thinking too, although I guess a check valve wouldn't hurt, right?

[mariner]

Hi Rob,

I wouldn't be surprised if your engine is fine. On some engines that have been worked hard, they smoke a little on idle. I think because there is very little pressure behind the rings when compared to heavy load. This in turn probably lets a small amount of smoke by the rings as they may not be sealing s good as they woould normlly do.

I am not saying that is the case or that is what is happening, just bringing the point up - that being when the engine works hard, it most likely the rings seal a little better due to the increased pressure.

Are you getting any liquid (oil) condensing out from the smoke?

mariner

[baknblack]

3rrl said:

Dwayne,
Thanks,
That's what I was thinking too, although I guess a check valve wouldn't hurt, right?

If it were me, I'd try it without 1st.

If you could somehow run a hose right off your vented cap would be ideal.

I really don't know how these engines passed EPA just letting the blow by out into the air.

[3RRL]

mariner said:

Hi Rob,

I wouldn't be surprised if your engine is fine. On some engines that have been worked hard, they smoke a little on idle. I think because there is very little pressure behind the rings when compared to heavy load. This in turn probably lets a small amount of smoke by the rings as they may not be sealing s good as they would normally do.

I am not saying that is the case or that is what is happening, just bringing the point up - that being when the engine works hard, it most likely the rings seal a little better due to the increased pressure.

Are you getting any liquid (oil) condensing out from the smoke?

mariner

Thanks for the replies Jim and Dwayne.
My initial concern with this problem was whether or not my engine really needed an overhaul due to the excessive blow...at least I thought it to be excessive. What I've learned from all the responses is that it not necessarily excessive at all, in fact pretty normal. So that's made me feel better about it.

Yes, there is a little oil that forms around the valve cover and vent after running most of the day. It's not a big mess, but it is a spot that gets oily and of course dust and crap sticks to it. If possible, I'd like to do what Dwayne is suggesting to reduce/eliminate that problem.

That is, to run a hose from the breather cap directly to the air filter or intake manifold. To me, that seems like a simple solution. I would leave the mesh straining element in the breather cap so any oil that condenses on it will fall back into the valve cover. The remaining gases that exit from the breather would go directly into the air filter or intake manifold. They would be sucked (consumed) back into the engine and burned.
Does that make sense?
If that is OK to do, then where would the best place to make the junction be ... into the air filter or into the intake manifold?
Rob-

[baknblack]

intake manifold, the oil vapors will screw the filter up.

[3RRL]

OK, thanks Dwayne.
That will be happening very next chance I get ... right after the other million things on my plate! I do want to move it up the list though. I've been spending time on Loretta's tractor that I've neglected Huge Kama. I was up there last week for 5 days and never even fired it up!
Rob-

[arveeotto]

Rob
If it were me, I would not use a PCV valve, although it works great on a gas engine, you do not have the same vacuum on a diesel intake manifold. A diesel does not use a butterfly valve to change engine speed as a gas burner does, which in turn creates the vacuume that you would need. I would use the sealed cap if you can find one, so that the vapours only have one place to exit, into the intake manifold.
Rick