We build gen sets for severe conditions and long intervals without on site maintenance. We are just finishing up winter down south and had an interesting event. There was a power failure with a storm and one gen set was run at full load for 10 days instead of its usual emergency runs of 5-10 hours. The 10 day run ended when the generator melted. Because of the emergency it was run at over its rated capacity. The crankcase oil temp in the diesel went off the scale which only reads up to 280F. This all happened in an ambient temperature of -41F. The oil used is a custom brew, a polyol ester base stock from a French company that if you use traditional labels would be classified as a 0w-5. We do this to have our best chance of starting the engine when it's cold and the set goes up to rated load in 60 seconds. Anyhow, after a partial tear down and inspection there was not damage to the valve train, cylinder walls or bottom end bearings. I was surprised at how well this really thin oil held up under high temperature and a heavy load over a long duration. I've always been nervous about these modern thin oil in tough applications but this event has made me a convert. A few gaskets, seals, a new batch of oil and a new generator and coupling and it's back in business.
Thin oil and high temps in a diesel...
- Thread starter OneEyeJack
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Is anyone using the experience to change the specified maximum load, and or improve cooling so the generator will not be damaged in a similar way the next time?
dnewton3
Staff member
On topic: I'm not "supprised" but pleasantly amused that the thin oil did so well. I must admit such a thin oil does make one wonder just how thin is "too thin".
Off topic:
Originally Posted By: JimPghPA
Is anyone using the experience to change the specified maximum load, and or improve cooling so the generator will not be damaged in a similar way the next time?
I am supprised that such as (presumably) expensive piece of equipment does not have automated shut-down or drop-out features to protect itself. If I read the post right it was the gen head itself that melted down, and the heat conduction into the crankcase sent the engine temps off the chart. Is there not a thermal breaker or other protection device? Seems odd to me.
Off topic:
Originally Posted By: JimPghPA
Is anyone using the experience to change the specified maximum load, and or improve cooling so the generator will not be damaged in a similar way the next time?
I am supprised that such as (presumably) expensive piece of equipment does not have automated shut-down or drop-out features to protect itself. If I read the post right it was the gen head itself that melted down, and the heat conduction into the crankcase sent the engine temps off the chart. Is there not a thermal breaker or other protection device? Seems odd to me.
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JHZR2
Staff member
Those oil temps are high, butyou say you're in CA and it is -41? Not likely. I guess you are really someplace else.
Seems that with ambient of -41, there would be a LOT of cooling going on. Obviously there wasn't. Was it snow or ice packed? No airflow?
Could the generator have been bad (separate issue) and caused the heating of the oil?
Sounds like a generator issue vice an engine issue until proven otherwise??
Seems that with ambient of -41, there would be a LOT of cooling going on. Obviously there wasn't. Was it snow or ice packed? No airflow?
Could the generator have been bad (separate issue) and caused the heating of the oil?
Sounds like a generator issue vice an engine issue until proven otherwise??
How far down south-Antarctica?? This confirms my hypothesis-if you can control evaporation and leakage of the engine oil-THINNER IS BETTER!! PERIOD!! Is there ANY chance of getting a used oil analysis on that oil to see what the viscosity & shearing loss caused by this event was?
The over temp breakers were disabled because of the emergency. This gen set was very near the bottom of the earth, not California. I'm in California but our work is many other places.
About the ambient temps. It only matters at start up and during warm up. Once things are up to temp, hot is still hot. These gen sets must be light, transportable by airplane and sometimes drug behind a snowmobile. Once in a while it's a human safety mater to keep the generator going, even as it is getting overloaded and this was the case this time. There were multiple system failures because of a bad storm. We new from the telemetry that a failure was coming but the decision was made to keep it going as long as possible and the extra run time was worth the expense.
Because of this incident and the post failure analysis we are going to upgrade our oil specs now that we have some more real world experience. Some of us are old timers that are used to using thicker oil but we can still learn.
About the ambient temps. It only matters at start up and during warm up. Once things are up to temp, hot is still hot. These gen sets must be light, transportable by airplane and sometimes drug behind a snowmobile. Once in a while it's a human safety mater to keep the generator going, even as it is getting overloaded and this was the case this time. There were multiple system failures because of a bad storm. We new from the telemetry that a failure was coming but the decision was made to keep it going as long as possible and the extra run time was worth the expense.
Because of this incident and the post failure analysis we are going to upgrade our oil specs now that we have some more real world experience. Some of us are old timers that are used to using thicker oil but we can still learn.
Interesting story. It's nice to hear about applications in extreme conditions. Years ago, I was on an engineering project team to develop an oil-cooled diesel. The engine had many problems with heat due to the relatively poor heat transfer characteristics of oil.
It wasn't until many years later that I began to think we had taken the wrong approach. Why not lubricate the engine with antifreeze, instead of trying to cool it with oil? Ethylene glycol might be too thin, but perhaps propylene glycol would be better. Just think; with stable viscosity, cold start lubrication issues would be a thing of the past.
It wasn't until many years later that I began to think we had taken the wrong approach. Why not lubricate the engine with antifreeze, instead of trying to cool it with oil? Ethylene glycol might be too thin, but perhaps propylene glycol would be better. Just think; with stable viscosity, cold start lubrication issues would be a thing of the past.
Hi,
A_Harman - There are a number of very good aircooled high speed heavy diesel engines. One of the biggest problems that you will be aware of is noise - another is emmissions management in an overall sense
A_Harman - There are a number of very good aircooled high speed heavy diesel engines. One of the biggest problems that you will be aware of is noise - another is emmissions management in an overall sense
The Continental AVDS-1790 comes to mind as a good air-cooled diesel, but air-cooled engines are limited in BMEP capability. Deutz started out with air-cooling, but as they pushed specific output higher, they eventually went to oil-cooling.
The engine I was involved with was designed from the outset with oil cooling to make a high-power-density diesel for military use. Being that it was military project, the only emissions that we were concerned with was visible smoke. NOx was of no concern.
The engine I was involved with was designed from the outset with oil cooling to make a high-power-density diesel for military use. Being that it was military project, the only emissions that we were concerned with was visible smoke. NOx was of no concern.
Just a follow up. We have another emergency going on right now as I post this message. This time it's a recovery operation for a helicopter crash down south. That gen set I wrote about is running right now, full bore and doing fine. This POE 0w-5 oil is the real deal. We upgraded the generator to take a bigger load and we've upped the temp settings on the diesel engine.
What I wanted to post was an interesting experiment we are doing with the fuel. We store a small amount of fuel in a start up tank that is kept sealed from outside moisture. As the engine heats up we warm up the fuel as it comes into the filters and the injection system and make a big effort to take all the moisture out before it hits the high pressure fuel pump and the injectors. We are getting a quicker light off and a much cleaner burn at full load. It is really making a difference over a several day's run. We are getting more electrical energy out of a gallon of fuel, not a lot but every little bit matters when it's a long way to fill up again. It's a consistent 2-3% and at freeze your buns off temps that's a big deal. A mechanic working on the gen set that failed broke two box wrenches out in the cold weather, they just broke off in his hand. All the experts are arguing over what's going on so I though I'd post this and see what you have to say. And remember that this is all going on at temps from +10F to -45F and once in a while a few degrees colder than that.
What I wanted to post was an interesting experiment we are doing with the fuel. We store a small amount of fuel in a start up tank that is kept sealed from outside moisture. As the engine heats up we warm up the fuel as it comes into the filters and the injection system and make a big effort to take all the moisture out before it hits the high pressure fuel pump and the injectors. We are getting a quicker light off and a much cleaner burn at full load. It is really making a difference over a several day's run. We are getting more electrical energy out of a gallon of fuel, not a lot but every little bit matters when it's a long way to fill up again. It's a consistent 2-3% and at freeze your buns off temps that's a big deal. A mechanic working on the gen set that failed broke two box wrenches out in the cold weather, they just broke off in his hand. All the experts are arguing over what's going on so I though I'd post this and see what you have to say. And remember that this is all going on at temps from +10F to -45F and once in a while a few degrees colder than that.
Originally Posted By: bullwinkle
hypothesis-if you can control evaporation and leakage of the engine oil-THINNER IS BETTER!! PERIOD!! Is there ANY chance of getting a used oil analysis on that oil to see what the viscosity & shearing loss caused by this event was?
Sounds like they rebuild those engines on a constant basis
Thin is not better -
thin means more wear more maintenance
Why some continue to push thin oil is beyond me -- for what gain
MPG gains are almost negligible - so to what purpose ?
other than to satisfy ones ego that his opinion was correct.
What they use in the arctics has no real life application for North America or Europe
hypothesis-if you can control evaporation and leakage of the engine oil-THINNER IS BETTER!! PERIOD!! Is there ANY chance of getting a used oil analysis on that oil to see what the viscosity & shearing loss caused by this event was?
Sounds like they rebuild those engines on a constant basis
Thin is not better -
thin means more wear more maintenance
Why some continue to push thin oil is beyond me -- for what gain
MPG gains are almost negligible - so to what purpose ?
other than to satisfy ones ego that his opinion was correct.
What they use in the arctics has no real life application for North America or Europe
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Originally Posted By: badnews
Originally Posted By: bullwinkle
hypothesis-if you can control evaporation and leakage of the engine oil-THINNER IS BETTER!! PERIOD!! Is there ANY chance of getting a used oil analysis on that oil to see what the viscosity & shearing loss caused by this event was?
Sounds like they rebuild those engines on a constant basis
Thin is not better -
thin means more wear more maintenance
Why some continue to push thin oil is beyond me -- for what gain
MPG gains are almost negligible - so to what purpose ?
other than to satisfy ones ego that his opinion was correct.
What they use in the arctics has no real life application for North America or Europe
+1
Originally Posted By: bullwinkle
hypothesis-if you can control evaporation and leakage of the engine oil-THINNER IS BETTER!! PERIOD!! Is there ANY chance of getting a used oil analysis on that oil to see what the viscosity & shearing loss caused by this event was?
Sounds like they rebuild those engines on a constant basis
Thin is not better -
thin means more wear more maintenance
Why some continue to push thin oil is beyond me -- for what gain
MPG gains are almost negligible - so to what purpose ?
other than to satisfy ones ego that his opinion was correct.
What they use in the arctics has no real life application for North America or Europe
+1
Actually these engines are not rebuilt as much as freshened up now that we have the new POE oil. The engine we freshened up with the burnt generator required no hard parts, just seals and gaskets. It survived a high temp run quite well when the oil is up over 280F for quite a while. I don't think being down south matters much once the engine is warm, hot is hot. What we do in extreme environments effects what we do everywhere else. I think we have a handle on start up wear, that is wear at crank and during warm up. The wear during the warm up run is more critical than cranking wear. Pressuring up the oil system before cranking showed no change in overall wear when compared to similar installations without the pre-oilier. We have gen sets in the desert in Libya were ambient temps are 125F+ and we are running 0w-20. We have a trial running right now with 0w-5 in three of those sets and so far no problems. I know a lot of people on this site are experts and won't agree but we can only go on our results. We find that some common knowledge about oil does not always work. We have the technical department of an oil company helping us with lubrication and we have hundreds of sets out and about. It looks like these new oils are earning their keep.
in 1984 i bought a new car. the manual said to run the heavest oil and still get it started in the cold. but in kansas you cant predict the weather good. this was in the heavy duty service section. i still follow that idea. how ever a few years ago temp went to +10 f i had 20-50 racing oil in a dodge hi per 360. it didnt start. had to change oil in the driveway (+10 degrees) i put 10-30 in, cause of the cold. later on i have gone to Valvoline premium blue diesel 15-40. so far so good, but i know some day ill have trouble. thats just the way cars and kansas are. new subject: if i had known i was going to last this long i would have taken better care of my self.
Originally Posted By: OneEyeJack
Actually these engines are not rebuilt as much as freshened up now that we have the new POE oil. The engine we freshened up with the burnt generator required no hard parts, just seals and gaskets. It survived a high temp run quite well when the oil is up over 280F for quite a while. I don't think being down south matters much once the engine is warm, hot is hot. What we do in extreme environments effects what we do everywhere else. I think we have a handle on start up wear, that is wear at crank and during warm up. The wear during the warm up run is more critical than cranking wear. Pressuring up the oil system before cranking showed no change in overall wear when compared to similar installations without the pre-oilier. We have gen sets in the desert in Libya were ambient temps are 125F+ and we are running 0w-20. We have a trial running right now with 0w-5 in three of those sets and so far no problems. I know a lot of people on this site are experts and won't agree but we can only go on our results. We find that some common knowledge about oil does not always work. We have the technical department of an oil company helping us with lubrication and we have hundreds of sets out and about. It looks like these new oils are earning their keep.
I still say that he's on the right track here-the vast majority of wear occurs at start up-and if you run a QUALITY SYNTHETIC-thinner is better. I'm referring to Group IV & V here-which limits the selection to RedLine, Amsoil, RP, possibly Delvac 1. There has to be a reason (besides MPG) that almost all the major manufacturers are trending towards 0W oils. I don't pretend to know more than Mercedes, Toyota, even GM!
Actually these engines are not rebuilt as much as freshened up now that we have the new POE oil. The engine we freshened up with the burnt generator required no hard parts, just seals and gaskets. It survived a high temp run quite well when the oil is up over 280F for quite a while. I don't think being down south matters much once the engine is warm, hot is hot. What we do in extreme environments effects what we do everywhere else. I think we have a handle on start up wear, that is wear at crank and during warm up. The wear during the warm up run is more critical than cranking wear. Pressuring up the oil system before cranking showed no change in overall wear when compared to similar installations without the pre-oilier. We have gen sets in the desert in Libya were ambient temps are 125F+ and we are running 0w-20. We have a trial running right now with 0w-5 in three of those sets and so far no problems. I know a lot of people on this site are experts and won't agree but we can only go on our results. We find that some common knowledge about oil does not always work. We have the technical department of an oil company helping us with lubrication and we have hundreds of sets out and about. It looks like these new oils are earning their keep.
I still say that he's on the right track here-the vast majority of wear occurs at start up-and if you run a QUALITY SYNTHETIC-thinner is better. I'm referring to Group IV & V here-which limits the selection to RedLine, Amsoil, RP, possibly Delvac 1. There has to be a reason (besides MPG) that almost all the major manufacturers are trending towards 0W oils. I don't pretend to know more than Mercedes, Toyota, even GM!
This week we start a test with the 0w-5 oil in several gen sets in the hot desert. So far in one parallel test, that is one engine with 0w-20 and one with 0w-5 and the oil temps after a full load run of 4 hours shows the the 0w-5 at about 10F cooler than the other. The temps are 220F and 230F, both ok for our purposes. This is too little testing to say one runs cooler than the other, for sure.
If the 2 gensets have identical or near-identical loads & run time-I'd like to hear what your fuel savings is (percentage)-sounds like with a 10F temperature drop, friction is definitely lower during operation. We hyper-miler diesel drivers are looking for every break we can get!
To make the test more reliable, even if it's only between these 2 engines, fill up with the other engine's oil viscosity type at the next oil change. See if the lower temps track/follow the oil switcheroo.
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