Forum for air cooled diesel engines and clones

[90cummins]

A friend of mine just received an L70 Yanmar from e-bay that looks to have been wet-stacked. The oil screen had globs of jelled oil on it but no metal and the valve cover was scuzzy inside.
I told him to install a 200psi pressure gauge on it clean the screen and refill with any auto oil such as 5w30 and run it for a couple minutes while watching the oil pressure then drain it and check the screen again.
Do this as many times as necessary until the oil; comes out clean while running it longer between each change.
You never want to see metal constantly appearing on the screen.
When you have the crankcase flushed run the engine at 50 to 80% load to get it up to temperature while monitoring the oil pressure.
Keep checking the filter screen by tipping the engine on it's side. You can then pull the screen & check it without draining the oil.
If you can get to run it for 2 or more hours at load without any metal accumulating on the filter screen I would consider that a good sign.
Finally drain the oil and refill with a good quality diesel oil, my preference is Shell Rotella 5w40 synthetic.
These engines need to run under load and in a cold environment they need to be sheltered from the wind to help them get up to operating temperature.
Diesels run cooler than gasoline engines.
90cummins

 

[bf109v7]

I Have a M.C. KAWASAKI 16 HP and 558 cc. It looks like a yanmar clone, but in the housing is cast in "made in Japan". I bought it in the Philippines, and here they print labels of all kind. Up to now it ran fine for 10 hours.
Did anybody see an engine like it?
And I could use a lttle bit more power and think to put a turbo charger and intercooler on it. anybody has experance with this?
Alex

 

[90cummins]

No!
90cummins

 

[bf109v7]

No!
90cummins

Only you or everybody?
Alex

 

[normde2001]

Engines is engines. What do you reslly need to know? Forget the turbo, for more power, you need a bigger engine

 

[bf109v7]

No. Engine is not engine. Some are light and some are heavy. And this one is the most powerfull of the light single cylinder air cooled diesel engines. And I do have a turbocharger and an intercooler, I donｴt have to buy them.
But I bought an head gasket today for this engine, and the gasket is for a bore of 86. And a bore of 86 is for the typ 186, which has only 10 HP and 406 cc with 70 stroke. 556 cc with a bore of 86 would mean a stroke of 96!

 

[90cummins]

In my previous post my friend bought a surplus L70 Yanmar and a new 5kw generator head so he could build a diesel gen-set on a budget.
He put it together and mounted it then brought it to me so I could test it and set it up.
During testing it was a bit rough with an occasional miss at hi speed so I pulled the injection pump to inspect the lifter.
The lifter was gouged and the injection cam lobe had rust and a pit in it where the cam and lifter had set during storage with moisture in the oil.
It corroded both pieces so a teardown was done.
The rod bearing had signs of distress and the interior of the engine was absolutely filthy with deposits that could not be removed with any of my solvents.
He took the cases to Napa to have them hot tanked and I kept the internals to prevent damage from handling.
The flywheel side main bearing is a large ball bearing and the bearing cage was packed with sludge that solvent would not remove.
I went to Walmart looking for a cleaner that could clean the parts, after reading all the labels and warnings I bought (2) 2-1/2 gallon jugs of Purple Power at $13 each.
I poured them into a large 7 gallon bucket and placed the crankshaft & other internal parts in there for the night.
The next morning I removed the parts and was stunned; the parts looked brand new!
Even the ball bearing cage was clean. Fantastic cleaner!!
After inspection and ordering parts, new piston, rings cam and lifters I worked on the crankshaft polishing the rod journal and seal surfaces.
The cylinder bore cleaned up nicely showing very minor wear at the very top of the cylinder.
When the parts arrived we assembled the engine and fired it up and put it under load.
It ran much smoother and developed full power after we advanced the injection timing.
After five minutes we shut it down and pulled the oil filter screen for inspection, minor particles were found so we cleaned it, reinstalled it and continued the break-in.
After an hour or so of running and 2 oil changes during which the filter was found to be clean he took it home for his new backup system.
Mission Accomplished!!
90cummins

 

[bf109v7]

I could not wait, I took out the injector and checked the stroke with a welding wire. I measured 75, could be +/- 2. I am disappionted. So it cant be true
what is written on the sticker.
Alex

 

[Volp]

The problem is incomplete combustion and low stack temperature due to the engine being lightly loaded.
For odd jobs and putting around a gasser is the superior engine. For long hard operation at full power, the diesel is the preferred choice.

I have now added two more meters on my generator as you can se in the picture below.
The right one gives the oil temperature measured at the bottom of the Yanmar engine. I replaced the rear drain plug with a new one holding a temperature sensor.
The left one gives the exchaust temperatur. I drilled and tapered a M5 hole in the exchust collector on the engine.
The exchaust temperature follows the load closely. Around 180 Centigrades at idle and about 460 degrees at full load.
I am not shure of the optimal temperature to avoid wet stacking. The knowledge must be somewhere on this forum! :biggrin:

Anders

 

[Ilikeurtractor]

Nice work. I'm not sure of the "optimal" temperature either, but at least you're above the condensation temp of water so that's good. The other problem is even if the optimal temperature is, say 300°C, it won't necessarily be easy or make sense to maintain that temperature. Like burning wood in a wood stove, there is an optimal range of 300-550°F to prevent creosote formation but I found that you'd need to be fiddling with the stove air/wood supply to maintain those values which isn't something I'd want to spend doing all the time. Letting a fire die out guarantees you won't be at the minimum 300 temp for a while. I would think as long as you're hitting decent loads over 50% capacity for 10-15 minute periods wet stacking shouldn't be an issue. I've ran tractors at pretty low loads (<20%) for a couple hours here and there and never noticed a wet stacking issue.