Chinese horizontal singles

[JMW]

Can anyone tell me how the crankcase breathing works on these engines.

Does it just vent into the surrounding atmosphere? I can't see anywhere it could be directed into the air intake.

Is there a reed valve or something that maintains negative pressure?
Would the bearings leak oil without this negatve pressure?

Mark

[mjn]

My Changfa 195 has a breather valve in the area under the fuel tank.  it just vents into the air.  At full power, a haze of smoke/oil comes out.  I used a piece of vinyl tubing to route the vapors back to the intake.  This helps eliminate the film of oil that collects on the speed control lever and spring.

[mobile_bob]

maybe that cloud of oil mist keeps the spring from rusting and the linkage lubed

don't laugh it would not surprise me in the least that the germans engineered or located the breather  to do just that.

might be interesting to see if the spring gets rusty or the lever starts to bind,
sometimes we correct things that looked to need correcting only to create a problem where one did not exist before.

i see this alot on various pieces of equipment,
the latest was the other day while working on a series 60 detroit,
the fuel trasfer pump has three holes thru the casting so there is a place for fuel to weep out if the seal gets bad
depending on how the pump is mounted (rotational position) you plug the two upper most holes with 1/8" pipe plugs to keep dirt and water
from running down into it, and leave the lower one open.
a well meaning mechanic plugged the bottom hole too, thinking it is threaded for a plug i will put it in.
the result is when the seal starts to leak it will fill the cavity and go past the oil seal and into the crankcase
with fuel dillution of the oil as the result and possible engine damage in the end.

with that plug in place the next mechanic would likely have half the engine apart trying to find out how the fuel is getting in the oil, never
thinking of the possibility that a well meaninged guy plugged the weep hole.

moral of the story is,, perhaps one should determine all the reasons something is built the way it is before modifying it.

rusted govenor springs break far sooner that oily ones, broken govenor springs lead to runaway engines and possible damage the result.

just something to consider, may not be an issue for everyone,, but might be a serious issue to a guy with a 195 in a humid environment
i don't know ?
bob g

[JMW]

Yeh. This is the problem I'm having. I can easily understand the existence of a tiny breather tube in a multi-cylinder engine where pistons are moving out of phase with each other, therefore the total air displacement within the crankcase is stable and small.
In a single cylinder engine, the piston displaces as much air in the crankcase as it does in the combustion chamber.
Where does it all go/come from?
It can't all go down that breather tube!

 

Mark

[draganof]

There is so much airflow past my 195 that I have never seen any haze. But it does keep the spring from getting rusty and nobody wants to let their spring get rusty. Just think of it as an automatic governor spring lubricator. Part of Caterpillars inspection checklist is greasing the governor linkage, Well on the Changfa it's done for you.

John

[Doug]

Bob:

Where does this German thing come from ?

The oldest versions of this engine I can find are Kubota.

Doug

[mobile_bob]

Doug:

i cannot tell you for sure, but i did see a german engine picture last year that looks remarkably like the changfa
so perhaps that engine is the papa of the kubota and changfa of this design.

kubota being japanese and them being buddies with the germans ,, who knows, maybe?

i didn't save the link, but i may have saved the pic,,, but i have no idea where.
if it comes up i will post it.

bob g

[Doug]

PLease try and find it Bob. A little history goes a long way in understanding.....


Doug

[europachris]

I seem to recall it was an old Hatz diesel that looked rather similar to the Kubota and/or Chinese singles.  Obviously the Chinese engines are cheaper "clones" of the Kubota horizontal singles, but the design definitely came from somewhere else. 

I'll bet that the Kubota design is a mish-mash of several diesel designs (mostly all German) rolled up into one. 

But, I have never seen an engine outside of the Chinese or Kubota that looked close enough to be called the 'father' of them without a lot of re-engineering.

[mjn]

Bob you could be perfectly right about the "Self Lubricating Governor Spring (tm) patent pending".

However,  the breather valve has an altogether too convenient 8 mm opening.  A piece of 5/16 tubing slips in as though it was designed for that purpose.  I suspect that some accountant told the Chinese factory that they could save .001 Yuan by leaving off the breather tube.

I don't get a lot of smoke or oil, but it is enough that I wanted to do something about it.

[europachris]

My Changfa 195 has a breather valve in the area under the fuel tank.  it just vents into the air.  At full power, a haze of smoke/oil comes out.  I used a piece of vinyl tubing to route the vapors back to the intake.  This helps eliminate the film of oil that collects on the speed control lever and spring.

My R185 has a breather on the crankcase cover at the back of the engine.  It's a little tube that sticks out.  There's a reed valve arrangement in there as I can hear it 'squeak' when I roll the engine over slowly.

I've not seen any other breather on the engine - I'll have to look up under the fuel tank, nor do I see any crankcase vapors coming out from anywhere on the engine.  It's totally tight and dry.

Chris

[rcavictim]

My Changfa 195 has a breather valve in the area under the fuel tank.  it just vents into the air.  At full power, a haze of smoke/oil comes out.  I used a piece of vinyl tubing to route the vapors back to the intake.  This helps eliminate the film of oil that collects on the speed control lever and spring.

My R185 has a breather on the crankcase cover at the back of the engine.  It's a little tube that sticks out.  There's a reed valve arrangement in there as I can hear it 'squeak' when I roll the engine over slowly.

I've not seen any other breather on the engine - I'll have to look up under the fuel tank, nor do I see any crankcase vapors coming out from anywhere on the engine.  It's totally tight and dry.

Chris

Chris,

My Jiang Dong 175A has exactly the same breather tube on the upper part of the rear crankcase cover.  Inside the cover is a reed valve also and a sandwhich baffle to separate oil from the breather air.  I ran a run of rubber fuel line hose to a port I made in the new intake manifold.  I never yet have seen any smoke out of this vent (my engine is near new and has no ring blowby) but there is a trace of oil mist present which if allowed to escape into the engine room would degrade the breathing air. Confined air with fine oil particles suspended in it is really bad for you. In fact it can kill you.  Same hazard exists in the exhaust from mechanical vacuum pumps (excepting the turbomolecular variety, but nobody I know owns one of those pricey jewels).

[wiebe]

Bob:

Where does this German thing come from ?

The oldest versions of this engine I can find are Kubota.

Doug

hi all i think its a clone from this engine/
http://www.youtube.com/watch?v=MxteeJvnfMY

greetings wiebe

[M61hops]

It could very well be.  However I think the motor in the vidio is a hit & miss gasoline engine and the valves on my changfa are side by side in a horizontal plane.  The cam in my changfa is under and parallel to the crankshaft.  The breather is a small tube that sticks out the top corner of the rear cover plate and has a reed valve and at least one baffel.  I really like the design of the changfas but my 175A is really noisy to run.  The 6-1 listeroid is the quietest diesel I have ever heard and noise is my most important consideration.       Leland