Excessive Blow-By Kama 554

[3RRL]

I'm nearing 500 hours (on the clock) on my Kama 554. I've noticed excessive blow-by coming from the breather cap on the valve cover. It's become more apparent than before. I can see oil fumes (smoke) getting pushed out the little holes in the breather cap and the valve cover gets oily when it's been running for a long time.
There are no water leaks and the engine runs good. It does not overheat either, but uses oil more than before.
-Does anybody else have that problem?
-Is it normal?
-What causes that and what can I do to fix it?
Rob-

[harryg]

You should have some type of crankcase breather system. Check it for being plugged. Some have a hose that can collapse and the crankcase gets pressurized. that pressure has to go somewhere.
I'm hoping its something simple like this. If not it sounds like rings, piston, liner, valve seals/guides, etc.
What oil are you running? Oil level correct?(as in not making oil).


You didn't say how much oil you are using or how bad the fumes are but if not too bad I'd leave it as is.

[3RRL]

Thanks Harry,
I'll have to look for the crankcase breather. Anybody know where it could be on the Kama 554?
I've been running Mobil1 20w50 for the last 400 hours. Oil level is good (I check it) and I've added two quarts over the last 60 hours. It's due for a service at 500 hours again. The blow by is tolerable, but gets worse at the end of the day.
I was wondering if the need for valve lash adjustment would cause some of that too? Otherwise If not it sounds like rings, piston, liner, valve seals/guides, etc. lol ... what else?
Rob-

[harryg]

Well, it is using a little oil but 1 quart per 30 hours isn't anything I'd tear an engine down over.
Valve lash set incorrect can cause multiple problems but wouldn't have anything to do with using oil. Bad/worn valve seals or valve guides would. Worn piston rings can cause oil consumption and or excessive blow by.
I'd check the breather system first. I don't know how the Kama engine is set up as I have a Jinma. the Jinma has a tube from the crankcase that goes up to a cannister with coarse steel wool (kinda like a old time miniature oil bath air filter) and then a hose to the valve cover. It basically makes a loop for the air so the gases can escape and fresh air can replace it.


I had a PCV system hose on a car plug and it pressurized the crankcase so bad it aerated the oil in the oil pan. the engine had a noise due to oil starvation.


Oil bath air cleaners, damn, I must be getting old. ;D

[quikduk]

I wouldn't necessarily worry about it. If 100 hours = 10,000 miles, then 10 hours = 1,000 miles.

That being said, my former BMW was considered to be "o.k." if it used 1 quart every 1,000 miles but it did have hard chrome rings and very hard cylinder liners. Therefore, you are using a quart every 3,000 miles...and your use is considered much "harder" than most.

I would tend to think it is your valves so perhaps another adjustment is in order. I would try that first and make sure there are no obstructions in your crankcase ventilation circuit.

[3RRL]

I see the crankcase vent on Loretta's Jinma. My Kama doesn't appear to have anything like that. What it has is a breather cap on the valve cover but nothing I could see in the crankcase itself.
I took these photos this morning.
They are looking at the left side of the engine where the starter motor is. I want to know what that is, what does it do?



I took the 2 bolts off to remove the cover, but I think it must have a shank or something in it because the cover did not just pop off. See that screw in the 3rd photo, do I need to loosen it first? I stopped since there is nothing in my manual about it and I don't know what it's for. The starter is in the way of that set screw.
I was thinking of drilling a hole in that cover to add a crankcase vent like on the Jinma if it goes to the crankcase.
Rob-

[harryg]

There has to be an inlet and an outlet for a crankcase ventilation to work.
Where's Chip (Artrac)when you need him? ;D

[Artrac]

My ears are burning! To the best of my knowledge the KAMA vents through the oil fill cap, there is a "steel wool" filter built into it. Even on the TS series with Yangdong engines, on the KAMA they plug the port on the intake that Jinma used for the vent tube, running the crankcase fumes/smoke throught he intake and out the exhaust. I"m not sure what the capped off port is. I wondered if the block had a gas engine cousin that used that for a distributor mounting... I have a forklift with a perkins gas engine that is obviously derived from a diesel... very heavy built.

[bradblazer]

I checked mine out today. There is a pretty vigorous puffing of air coming from the holes in the breather while it's running and there is a small amount of oil on the surrounding surfaces. I didn't run it hard and did not see any fumes.

Here is a paragraph from Wikipedia (crankcase):
"Air ventilation
During normal operation, a small amount of unburned fuel and exhaust gases escape around the piston rings and enter the crankcase, referred to as "blow-by". [6] If these gases remained in the crankcase and condensed, the oil would become more diluted over time, decreasing its ability to lubricate. Condensed water would also cause parts of the engine to rust. [7] To counter this, a crankcase ventilation system exists to draw fresh air in from the air filter and expel the gases out the PCV valve into the intake manifold. The intake manifold is at a lower pressure than the crankcase, providing the suction to keep the ventilation system going.

If an engine is damaged or enters old age, gaps can form between the cylinder walls and pistons, resulting in larger amounts of blow-by than the crankcase ventilation system can handle. The gaps cause power loss, and ultimately mean that the engine needs to be rebuilt or replaced. [6] Symptoms of excessive blow-by include oil being pushed up into the air filter, out the dipstick[8], or out the PCV valve."

[bradblazer]

Re-reading that it does not discuss the pumping action of the pistons which creates some air pressure changes in the case independent of blow-by. Even with multiple cylinders the pistons move faster at the top of the stroke than at the bottom so the positions do not balance.

[baknblack]

Rob, In your manual somewhere it states how much engine oil use is acceptable.

My Y485 has had blow by ever since it was new. Enough to use use a quart in 100 hrs. Mine vents from the side of the crankcase via a tube with a wool strainer on top. I had to put a hose on it to get the gases below the tractor and not blowing on my starter.

I consider this normal and drive on, lol.

[bracabric]

Rob. Sounds very like a blocked breather to me, some Diesels vent right back into the air intake so as to burn the blown past gas. Oil consumption is not so bad, nothing to brake the engine down for and by your own admission it's had a harder life than most.
Good luck anyway,
Dick

[3RRL]

Well, from what you guys have told me, I don't feel so bad about anymore. For a couple reasons...

First, it does not use oil terribly at all. I said it might have taken 2 quarts over the last 60 hours or so, but it's closer to 100 hours now that I think about it. Shees, It's getting near 500 hours on the clock now! So that's not THAT bad.

Second, Brad's description of how his Kama 554 acts, it is almost exactly what mine is doing.
I checked mine out today. There is a pretty vigorous puffing of air coming from the holes in the breather while it's running and there is a small amount of oil on the surrounding surfaces. I didn't run it hard and did not see any fumes.
Mine gets worse after it has run all day long though....that is worse than it was when it was first fired up in the morning. It usually take a couple hours to notice the "smoke" emitting from the breather cap. Otherwise it's not really noticeable. Brad, do you ever run your 554 for say 8 hours at a whack? If you do, check it for me if that makes a difference like it does to mine. There's a little more smoke that comes out of the breather and some oil residue around that area.

So Chip, I have a couple questions for you and the others who might know:

- Is there anyway of finding out what that cover is all about? That would be good to know. As far as I know, it is not mentioned in the engine manuals.
- Also, can you point me to where that old breather plug they put in? I would still like to add a crankcase breather, just to reduce the oil residue coming out of the valve cover breather cap.
- What are your feelings about running the breather cap exhaust back into the intake? I discussed that with Larry and he was not to keen on the idea of having residue enter the maniforld and possibly building up on the valves.
- What about running it connected to the exhaust stack or exhaust manifold then?
Thanks, Rob-

[Artrac]

I answered this on another forum, and didn't know what breather plug you were talking about, but I see I mentioned it on the Yangdong engine (TS series 254 and 354). On the Kamas with that engine, the intake manifold had a bolt or plug in it. on the jinmas, there was a fitting with a vent tube going to a different filler cap that had a vent through it. the cap on the kama is solid and the vent is through a tube on the side of the engine. on the Feidong engine in your KM, the vent is in the oil filler cap.

I also posted there that the mystery plate on the side of the engine is access to the drive for the oil pump. It is alonside the camshaft and removing the plate will give you access to the drive gear for the oil pump.

[3RRL]

Thanks for clearing that up Chip,
You've been a real help as usual. I'm thinking that I'll just live with the situation for the time being. If I need to get new valve guides, is that something you have in stock?
Rob-