Forum for air cooled diesel engines and clones

[CallMeColt]

I agree with injection timing, been there before.
Perfect injection timing is essential for a smooth running engine.
I have repaired 3 Yanmar air cooled diesels with the same issues.
Two L70 and one L100 clone.
The L70 had damaged camshafts from moisture which pitted the injection pump cam lobe.
The L100 clone had a bad needle bearing on the camshaft which in both instances effects the injection timing.
Remove the injection pump and cam follower and inspect the follower surface that contacts the camshaft.
Also look at the cam lobe as you slowly turn the engine. If there is pitting or spalling on the cam surface there is your problem.
Also remove the oil filter screen there should be no magnetic particles on it.
If so that is indicative of a failed cam bearing or lobe.
Photos of your findings (if any) will help.

90cummins

Sorry for the later follow up.

There was nothing at all wrong on the cam surface or anything. The inside of the engine was as if it was new when I opened it all up. Oil screen was clean as a whistle.

I ended up selling it for $200 to someone who wanted to take over. I put way to much time & effort into it. Needed some money to by something else much cooler that came up for sale.

Thanks for the follow up though.

 

[jamiegreen98]

Have to say an amazing thread here, hopefully still a few of you around. I've had my fair share of Chinese copy 186f's, including the Hyundai version which differs slightly again, but still managed to crack it's block 400 hours in. Replaced it with a china copy which the main bearing failed on at 200 hours and seized everything up. Rebuilt that one which lasted another 100 hours before... Well I don't even know what went wrong that time I had enough of it. About a month ago bought a HGI silenced generator with a genuine yanmar for a good price at 2500 hours (says it all really). The HGI (British manufacturer who makes a lot for the army) side of things is so well designed. Runs extremely quiet and the build quality and air flow diversion etc is brilliant. Anyway, the inside casing seemed to have a lot of oily residue so I stripped the entire thing down and cleaned it all up, looked great. Later discoverd a slight oil leakage from the inner air flow part of the head, baffled me because there's no gaskets there other than the head below and the rocker above. Anyway, changed the head gasket and oil seal, and just about every other gasket accessible. Leak back after couple days, then I found it, hairline crack in the head. Well that was annoying, and explained why the inner casing had gotten so dirty since the leaking oil was being blown around by the engine fan. Bought a new genuine head complete with valves from a engine repair shop for a fair price. New gaskets again, all torqued up and has now been running perfectly for past 50 hours or so, and absolutely no visable oil leaks.

So that's the story, now the questions.
First being pre heat, I rely on the geni for backup power off the grid and needs to start in the minus temps. The Hyundai had a standard car needle type glow plugged tapped into the air intake, so I did the same thing with the genuine and tapped a thread for a normal 100w glow plug in the intake. Controller heats it for 15 secs before cranking, obviously this is not the ideal use for a car glow plug, but will surely help, but I'm interested if anyone has any other pre heat ideas. I know you can buy grids for them but not for the l100 models. And I would have thought any sort of grid heater would be a bit useless before the air filter.

Next idea being the most interesting to me, adding a remote oil filter, a proper car one, would be great for the engine and widen the service intervals. Now I've seen people plumb the oil lines for fitting turbos, tap into the low oil pressure sensor hole which is directly connected to the oil pump, then up into the remote oil filter, then return to either the spare dipstick or the spare oil drain. Can anyone see any issues with doing this? As in it wouldn't stop the oil also being pumped to.. I think it goes to one of the bearings also? And would I be able to remove the mesh from the existing "filter" to bypass it as the remote oil filter will do all the work anyway.
Any ideas appreciated!

 

[jamiegreen98]

Have to say an amazing thread here, hopefully still a few of you around. I've had my fair share of Chinese copy 186f's, including the Hyundai version which differs slightly again, but still managed to crack it's block 400 hours in. Replaced it with a china copy which the main bearing failed on at 200 hours and seized everything up. Rebuilt that one which lasted another 100 hours before... Well I don't even know what went wrong that time I had enough of it. About a month ago bought a HGI silenced generator with a genuine yanmar for a good price at 2500 hours (says it all really). The HGI (British manufacturer who makes a lot for the army) side of things is so well designed. Runs extremely quiet and the build quality and air flow diversion etc is brilliant. Anyway, the inside casing seemed to have a lot of oily residue so I stripped the entire thing down and cleaned it all up, looked great. Later discoverd a slight oil leakage from the inner air flow part of the head, baffled me because there's no gaskets there other than the head below and the rocker above. Anyway, changed the head gasket and oil seal, and just about every other gasket accessible. Leak back after couple days, then I found it, hairline crack in the head. Well that was annoying, and explained why the inner casing had gotten so dirty since the leaking oil was being blown around by the engine fan. Bought a new genuine head complete with valves from a engine repair shop for a fair price. New gaskets again, all torqued up and has now been running perfectly for past 50 hours or so, and absolutely no visable oil leaks.

So that's the story, now the questions.
First being pre heat, I rely on the geni for backup power off the grid and needs to start in the minus temps. The Hyundai had a standard car needle type glow plugged tapped into the air intake, so I did the same thing with the genuine and tapped a thread for a normal 100w glow plug in the intake. Controller heats it for 15 secs before cranking, obviously this is not the ideal use for a car glow plug, but will surely help, but I'm interested if anyone has any other pre heat ideas. I know you can buy grids for them but not for the l100 models. And I would have thought any sort of grid heater would be a bit useless before the air filter.

Next idea being the most interesting to me, adding a remote oil filter, a proper car one, would be great for the engine and widen the service intervals. Now I've seen people plumb the oil lines for fitting turbos, tap into the low oil pressure sensor hole which is directly connected to the oil pump, then up into the remote oil filter, then return to either the spare dipstick or the spare oil drain. Can anyone see any issues with doing this? As in it wouldn't stop the oil also being pumped to.. I think it goes to one of the bearings also? And would I be able to remove the mesh from the existing "filter" to bypass it as the remote oil filter will do all the work anyway.
Any ideas appreciated!

Well I've done enough research to answer one of my questions. Not possible to add a remote oil filter (Simply) The oil pumps only real purpose is the feed the mesh filter and the main output "bearing" The oil pressure is regulated via a pinhole on the sump casing and is greatly effected by oil temp - viscosity. This means when cold oil can reach up to 250psi. If one added an oil filter this would become the main route for oil and would build up very little pressure as oil filters are pretty free flowing and most bypass at 15psi. Not good. the only real way to do this would be to remove the engine side and plug the pinhole and fit a new re-stricter pinhole (commonly used inline with turbos) or fit a adjustable pressure regulating valve before the remote oil filter. This would allow the engine to maintain standard oil pressure whilst feeding the remote oil filter low pressure oil before returning to sump. And thats more work than i'm willing to do as it involves removing the alternator etc. Maybe there will come a time but not yet.

 

[90cummins]

The Intake grid heater on the Dodge Cummins diesel would work.
You may need to use an automotive size battery because of the amperage it draws but that would most certainly work.
It is virtually identical to yanmars L70 but much larger


90cummins

 

[90cummins]

A filter could be added but would need to be as a bypass filter.
The screen you mention is on the suction side of the oil pump not after it.
Not a good idea to remove it.
You are correct there is no pressure regulation and the oil pressure approach 200psi when cold.
I have a L70 with a factory installed spin on bypass filter and an extended 2 quart oil sump which increases the oil Capacity to 3 quarts. It also came with a grid heater.
It was designed to operate 500 hours unattended in remote applications.
90cummins

 

[jamiegreen98]

I can't see a way of adding a bypass filter without dropping the oil pressure, and I imagine the floating "bearing" relies on good pressure. I guess a second pinhole oil restrictor could be added before the remote oil filter, for arguments sake lets say the original pinhole relief is 1mm, if I added a 0.25mm restrictor before the oil filter, I would be dropping the oil pressure (to the bearing) by.. 12.5 percent. Sine the engine would now have 1.25mm of hole to return to sump. Not sure on numbers but if the engine runs at 100psi warm I'd be dropping to 87.5psi instead. Not too sure if a 0.25mm restricter would allow a good enough flow of oil for a standard oil filter? Suppose it doesn't matter too much as long as it flows enough. How is your spinny oil filter plumbed? Suction side or high pressure side? Any info would be appreciated or pics.
As for the grid heater, I've seen those Cummins air intake heaters on US eBay, but wasn't quite sure where one would put it, I assume it would have to be fitted before the air filter which figured it might get clogged up?
Thanks

 

[90cummins]

I can't see a way of adding a bypass filter without dropping the oil pressure, and I imagine the floating "bearing" relies on good pressure. I guess a second pinhole oil restrictor could be added before the remote oil filter, for arguments sake lets say the original pinhole relief is 1mm, if I added a 0.25mm restrictor before the oil filter, I would be dropping the oil pressure (to the bearing) by.. 12.5 percent. Sine the engine would now have 1.25mm of hole to return to sump. Not sure on numbers but if the engine runs at 100psi warm I'd be dropping to 87.5psi instead. Not too sure if a 0.25mm restricter would allow a good enough flow of oil for a standard oil filter? Suppose it doesn't matter too much as long as it flows enough. How is your spinny oil filter plumbed? Suction side or high pressure side? Any info would be appreciated or pics.
As for the grid heater, I've seen those Cummins air intake heaters on US eBay, but wasn't quite sure where one would put it, I assume it would have to be fitted before the air filter which figured it might get clogged up?
Thanks

The grid heater should be on the engine after the air filter.
Placed before the air filter Could cause the filter to burn up.

Still looking for photos of my L70 bypass oil filter.

90cummins

 

[jamiegreen98]

The grid heater should be on the engine after the air filter.
Placed before the air filter Could cause the filter to burn up.

Still looking for photos of my L70 bypass oil filter.

90cummins

I suppose it would be a job of making some sort of custom intake manifold adapter to be able to bolt one of those intake heaters in. I assume the l48 intake is different to accept the genuine heater over the l100 which doesn't appear to have any fixings for one. But in all fairness to it, 15 secs on the car type glow plug this morning at 1 degrees and it started on the first stroke.

 

[90cummins]

As I mentioned some time ago I have an L70 Yanmar with a Factory option extra deep sump with a bypass filter.
The sump holds approximately 3 quarts. This engine was designed for remote applications requiring extended run times unattended. It also has an intake grid heater for extremely cold starts and is designed to run 500 hours between services.
There is a utube video of me starting it during a subzero cold stretch under username 90cummins.
I purchased it specifically to replace the 9hp L90 originally mounted to a 5000 watt generator head.
This was done to minimize fuel consumption with a short term capacity of 4kw with excellent surge capacity and voltage stability while still meeting my electrical requirements.
This works very nicely with my 4kw Xantrex hybrid off grid battery backup system.
During an outage if the load exceeds 3.2kw the inverter is programmed to assist the generator by pulling power from the batteries.


90cummins

 

[ponytug]

Wow! That's an amazing little engine. Thanks for sharing it. How did you find it? Do you have any insights on how the flow is partitioned between filter and the bearings?

All the best,

Peter