turbo owners: caution in transport

[ray66v]

There is residual oil even tho it is not flowing to carry away bearing heat. Oiled brass on steel is pretty happy. The question would be does the turbo spin at all. If so, is it fast enuf to cause it to run dry and forceful enuf that it doesnt stop as it dries. I dont think 25 rpm qualifys. Bushings with residual oil work for long periods with light sideload in electric motors. We are talking similar rpm as conjecture, but without load.
larry

Right, residual oil is capable of protecting the system from damage. it is not easily going to dry up, or burn off due to any amount of low speed. no load, low temperature, pinwheeling.

As an example of this, have you ever heard of the oil being drained from an engine and it being run until it fails? I have a friend that goes to bike week at Daytona every year. A form of entertainment there, is to put old, (japanese), motorcycles on a stage and drain all the oil, then run them WIDE OPEN until they blow. This takes much longer than you think. Why? residual oil. The residual oil offers protection, even at 8, 9, 10k rpm's, until the extreme heat caused by the continuous high rpm's finally destroys the oil.

 

[2Botas]

There is residual oil even tho it is not flowing to carry away bearing heat. Oiled brass on steel is pretty happy. The question would be does the turbo spin at all. If so, is it fast enuf to cause it to run dry and forceful enuf that it doesnt stop as it dries. I dont think 25 rpm qualifys. Bushings with residual oil work for long periods with light sideload in electric motors. We are talking similar rpm as conjecture, but without load.
larry

True, But turbochargers operate at extreme temperatures, and they retain alot of heat upon shut down. Due to this, what little bit of residual oil that is left in the turbo is often heated to such a degree after shutdown, that it is no longer very useful. Especially on the impeller side bushing. Often times proper procedures for shutdown of a turbocharged engine are ignored. Even if proper shutdown is observed, the standing temp of the oil left in the turbo can reach over 700 degrees Farenheit. At that point, that little skim coat of oil on the bushings, is no longer oil.

Yes, I was exagerating with the 25rpm

Bushings in electric motors are impregnated with graphite for lubrication. Or at least the wet environment motors that we use in the mill are. Also, the tolerances on those motors are not anywhere as critical as they are in a turbo.

 

[2Botas]

Right, residual oil is capable of protecting the system from damage. it is not easily going to dry up, or burn off due to any amount of low speed. no load, low temperature, pinwheeling.

As an example of this, have you ever heard of the oil being drained from an engine and it being run until it fails? I have a friend that goes to bike week at Daytona every year. A form of entertainment there, is to put old, (japanese), motorcycles on a stage and drain all the oil, then run them WIDE OPEN until they blow. This takes much longer than you think. Why? residual oil. The residual oil offers protection, even at 8, 9, 10k rpm's, until the extreme heat caused by the continuous high rpm's finally destroys the oil.

Drain the oil out of one of those bikes and see how long it takes for it to start knocking. As soon as it is knocking, it is causing damage. And that will only take 20-30 seconds. It will probably run for a good 5-10 minutes. But it was already doomed 30 seconds after startup.

 

[L4400]

Drain the oil out of one of those bikes and see how long it takes for it to start knocking. As soon as it is knocking, it is causing damage. And that will only take 20-30 seconds. It will probably run for a good 5-10 minutes. But it was already doomed 30 seconds after startup.

I had a BRAND NEW Troy-bilt mower that I started not knowing it didn't have any oil in it. It ran for about a minute and a half and locked up.

 

[ray66v]

I had a BRAND NEW Troy-bilt mower that I started not knowing it didn't have any oil in it. It ran for about a minute and a half and locked up.

Yes, probably because it did not have any oil in it.

My father has an old mower that he has forgot to replace the filler cap for the oil more than once. He has on more than one occasion mowed the lawn, 5 acres, with little to no oil in the engine because it all blows out the filler. Each time there was no sign of trouble until after he parked it, and saw oil on the floor of the garage. He refills the engine, puts the cap back on and it continues to run fine.

While I am certain this will not add any life to the engine, (it was worn out anyway), it has not done it in either.

 

[ray66v]

Drain the oil out of one of those bikes and see how long it takes for it to start knocking. As soon as it is knocking, it is causing damage. And that will only take 20-30 seconds. It will probably run for a good 5-10 minutes. But it was already doomed 30 seconds after startup.

Your speculating, but my friend is not, he has seen this year after year, and that is not what he has witnessed. He says they lock the front wheel and run the engines at full throttle with the rear tire on the ground spinning in a burn out pit.

He said they commonly run 10-15 minutes at full throttle, and full load, without even so much as a sputter. Sometimes the rear tire blows before the engines do.

 

[SPYDERLK]

True, But turbochargers operate at extreme temperatures, and they retain alot of heat upon shut down. Due to this, what little bit of residual oil that is left in the turbo is often heated to such a degree after shutdown, that it is no longer very useful. Especially on the impeller side bushing. Often times proper procedures for shutdown of a turbocharged engine are ignored. Even if proper shutdown is observed, the standing temp of the oil left in the turbo can reach over 700 degrees Farenheit. At that point, that little skim coat of oil on the bushings, is no longer oil.

Good point. Would you think that the very act of driving the item onto the truck would constitute a good approximation of proper shutdown? Also, Im thinking the equipment is often parked for awhile after work - then started and driven on "cold".
I really would like to know the answer to this. It just seems that some very specific conditions are occuring to get enuf air thru to spin the turbo at all. The restrictions of air filter and only partially open valves at enuf flow for spinup are significant to the miniscule pressures available moving thru air. Without extraordinarily bad luck of having the air cleaner in a high pressure zone and the exhaust in a very low pressure zone I cant imagine a differential pressure more than a few hundredths of a psi. And most of that would be across the air cleaner. It would not be trivial to set up a good test unless you happened to have all the right stuff. It seems like some of the major companies would have tho. Instead we get all hearsay under completely unknown conditions.
larry

 

[madslick]

Again,
I'll repeat my earlier post:
1) Block the exhaust to prevent moisture from getting into the turbos
2) Military transports of heavy equipment almost always block the exhaust of heavy equiment to prevent FOD (FOreign Object Damage) aka sand, birds, etc.

The turbo spinning is a MYTH based on old passdowns which weren't clear to begin with.

Cap the Exhaust stack for the 2 reasons above -- NOT THE SPINNING TURBO.

 

[ray66v]

Again,
I'll repeat my earlier post:
1) Block the exhaust to prevent moisture from getting into the turbos
2) Military transports of heavy equipment almost always block the exhaust of heavy equiment to prevent FOD (FOreign Object Damage) aka sand, birds, etc.

The turbo spinning is a MYTH based on old passdowns which weren't clear to begin with.

Cap the Exhaust stack for the 2 reasons above -- NOT THE SPINNING TURBO.

Amen, Todays oil does not break down from heat like the oil of years gone by. But, its a moot point because, if a 100 mph blower applied directly to the turbo barely turns it, it ain't gonna spin anyway.

 

[RobJ]

A form of entertainment there, is to put old, (japanese), motorcycles on a stage and drain all the oil, then run them WIDE OPEN until they blow. This takes much longer than you think. Why? residual oil. The residual oil offers protection, even at 8, 9, 10k rpm's, until the extreme heat caused by the continuous high rpm's finally destroys the oil.

This old jap bike wouldn't have been a 2 cycle? they'll run a long time without oil in the greas.