Letting Oil Drain Out for a week

[Compass790]

Originally Posted by a64pilot

I don’t know of any studies, reasoning is who is going to pay for the study?
Now a preluber doesn’t hurt, it was something that I used to really want, but then as I said they didn’t seem to make much difference.
Truth is it seems that in an automobile if an engine isn’t abused and is properly cared for, the car is going to be junk well before the engine is.
Wife’s Father has a Honda Accord I think, it has over 400,000 miles on it and doesn’t burn a drop of oil, car is in actually very good shape too.

When the cars that would shut themselves off at every stop first starting being made, I though that is stupid, these things can’t last very long, being shut down and restarted so often, and worse yet, as soon as they start, they are put under a load.
Every body knows that will kill an engine in short order, yet they seem to last, who knows how or why?

It would seem that a lot of our accepted “Facts” may not be?
Maybe back in the day of thick oils and super cold soaked auto’s in Michigan Winter or something is where the most wear occurs on start up started?

Yes what you say is true re engine life on modern cars without pre-oilers. Just hoped some Ph.D engineering student had done some experimental work that would prove it.
Guess I'll be dead or unable to go boating before I can " guess " if ours had any effect.

[Allied39]

Originally Posted by hellosailor

"on a new motor I change my oil every 50 hrs, ...
So, 1940's aircraft and synthetic oils did not even enter the thought process......huh, go figure?"

Well, perhaps some engineering history is in order while you're throwing away all that oil. I was taught that a hundred years ago, if you wanted to buy a Rolls Royce, you had to also engage a properly trained chauffeur. And one of the *routine* jobs of a Rolls chauffeur was to disassemble the engine and hammer the soft silver metal bearings back into shape every so many hours.

Yes, you routinely remanufactured the bearings as part of routine operation.

Engines have come a long way since then. Even in the 70's or 80's the bearings certainly were more robust than bearings used to be. So, pre-oiling a marine diesel, or any other consumer or light commercial engine?

Might be more along the lines of buying a nice whole fresh cow every time you wanted a steak. And then throwing out the other 1800 pounds of beef because, well, you know, it wasn't fresh any more.

If you send out an oil sample for analysis after you've run the engine for one hour, and then you send out another sample when you do the 50-hour change, I'd be really sure that the samples would come back identical, showing a total waste of oil, unless you've got something like fuel or coolant contamination issues going on.

Or are you the fellow that's been listing "Gently used marine engine oil, good as new!" on Craigslist?

Whatever, done with this.

[hellosailor]

Compass, there's no need to guess. Just pull the engine, ship it off to any good engine maker, and pay them to tear it down and do a wear analysis on the bearings. They do that routinely for every new engine design.

I don't think they, or anyone, really gets a lot of requests from the general public but there must be someone, maybe a university metallurgical engineering program, where they'd be glad to tear into it. Or, they might have reference texts that document just how these things have changed and improved over the years.

Then again, the SAE or ASI might have lab results they could cite and share, which show how the new oil standards have diminished wear in the new engines.

Dunno. I haven't heard of an engine failing from "oil" problems in many years, and even then, the only real problem was "didn't put the drain plug back in" or "never changed the oil". Owner abuse, not so much the materials. The big fleet operators also have numbers on commercial diesels, as do the major shipping companies. But once you hit Big Gray Boat scales, I think they mainly do analysis, and save the changes until they are needed, by an objective measure.

[Compass790]

Originally Posted by hellosailor

Compass, there's no need to guess. Just pull the engine, ship it off to any good engine maker, and pay them to tear it down and do a wear analysis on the bearings. They do that routinely for every new engine design.

I don't think they, or anyone, really gets a lot of requests from the general public but there must be someone, maybe a university metallurgical engineering program, where they'd be glad to tear into it. Or, they might have reference texts that document just how these things have changed and improved over the years.

Then again, the SAE or ASI might have lab results they could cite and share, which show how the new oil standards have diminished wear in the new engines.

Dunno. I haven't heard of an engine failing from "oil" problems in many years, and even then, the only real problem was "didn't put the drain plug back in" or "never changed the oil". Owner abuse, not so much the materials. The big fleet operators also have numbers on commercial diesels, as do the major shipping companies. But once you hit Big Gray Boat scales, I think they mainly do analysis, and save the changes until they are needed, by an objective measure.

haha I'm done pulling the engine I hope.
Actually I'm a bit amazed there is no study ( that I can find for free anyway) on pre-oilers as there is lots of stuff about engine wear whilst cold.
Yacht/Sailboat engines don't seem to last as long as car engines. I'm guessing that's coz of all the short runs. Yea I dont worry about oil failure.

[RobPatterson]

Originally Posted by Compass790

Yacht/Sailboat engines don't seem to last as long as car engines.

???
30-year old engine in service here.
Automobile gasoline engines rarely go 450,000 miles (less than 10,000-hours). Marine diesel engines routinely exceed that unless maintenance is neglected.

[a64pilot]

Our Prius keeps track of average speed, it was mostly highway driven, it had to be to get to 250,000 miles in seven or eight years, yet it’s average speed has been about 20 ish MPH. Assumption is all those stop lights etc really kill the averages.
Assuming 250,000 miles, and 25 MPH to keep it simple, that means it’s at 10,000 hours so far and does not burn a drop of oil.
Using the Father in law’s Honda as an example, it’s well over 20,000 hours, and still doesn’t burn oil.
Automobile engines can last a very long time, I believe a lot of that is due to that they are most often run at very low power when compared to say an aircraft or marine engine.
Average aircraft TBO is 2,000 hours, often less. Now they are rarely worn out then, but still that is a short time, and I believe it’s because they are almost always run hard.
Not usually fast, cruise on my IO-540 was 2200 or so, but hard.

I’d say it’s pretty much unheard of for a smaller high RPM Diesel like a Yanmar etc to get to 20,000 hours.
Gardner’s etc. are a whole different animal.