Buying Advice Turbo or not

[RickB]

The cool down time for a turbo is so you don't cut oil supply while it's still spinning high rims.

Like I implied earlier, 10 year reliability, no big deal. 30 to 50 year reliability, give me NA. How long do you hold onto a tractor?

Cool down time is also so you don稚 coke up a few drops of oil and a bearing set from an exhaust turbine that went from handling 1200 degree exhaust to shutdown in a handful of seconds. Cool down time lets the turbine temp lower dramatically when coming off anything resembling full load and high boost.

 

[Slowpoke Slim]

We were always told in my old service days, that you had to idle or "no load" the engine down after use to give the turbo a chance to spin all the way down to min rpms before you shut off the engine, to keep the turbo's bearings from starving for oil (cook off the oil and go metal-metal) and thus destroying the turbo. I think our heavy equipment had at least a 15 min minimum run down time before you were supposed to shutdown the engine. At least back then (80's through early 90's), there was no oil re circulation path to the turbo bearings once you shut down the engine. I think at least some modern heavy equipment/gensets have a "keep alive" oiling system now, that will continue to circulate oil through the turbo bearings even after the engine is off.

 

[Redneck in training]

I had aircraft mechanic training, and an aircraft with a turbocharger needs special training to fly it.. Aircraft Engine Turbochargers Explained... also, Aircraft engine parts, especially with the required repair/installation by a qualified mechanic, is VERY expensive.. everything has to be maintained on a schedule, and logged, and each aircraft has it's own schedule for that.. you can't be flying an aircraft that could suddenly lose power.. of course, a Tractor is a bit different, but, you still need to operate it properly to avoid a catastrophe...

I just tried to use little humor. I used to commission gas turbines (essentially jet engines) for living. Every gas turbine has control system that takes care of starting, running and shutting down the machine. I still commission steam turbines. They take more abuse but still they have control system preventing the users to shorten the life of the machine. Tractors doesn't have that so it is the user that has to follow the procedures or pay for it.

 

[Redneck in training]

We were always told in my old service days, that you had to idle or "no load" the engine down after use to give the turbo a chance to spin all the way down to min rpms before you shut off the engine, to keep the turbo's bearings from starving for oil (cook off the oil and go metal-metal) and thus destroying the turbo. I think our heavy equipment had at least a 15 min minimum run down time before you were supposed to shutdown the engine. At least back then (80's through early 90's), there was no oil re circulation path to the turbo bearings once you shut down the engine. I think at least some modern heavy equipment/gensets have a "keep alive" oiling system now, that will continue to circulate oil through the turbo bearings even after the engine is off.

Compact tractors have small turbos with not much rotating mass. They spool down generally in less than a minute. Temperature is another matter though. The turbine is very hot and the stator as well so to keep the engine running is necessary to circulate oil until the temperatures decrease. If stopped hot the turbo will cook the oil even when not spinning.

 

[TMGT]

And if you don't do it they will be happy to sell you new turbo. That is why there isn't safety timer. Tractor isn't an airplane.

I think lack of timers is probably due to the libility of an engine that keeps running for 5-15min after you shut it down..........

We use to install aftermarket timers when we added turbos or heavily modified turbo cars.

Newer OEM turbos are pretty good about handling immediate shutdowns, water cooling and ball bearings help a lot. Turbo technology has come a long way, even in the last few years.

That being said I always give my cars/equipment at least a few min of cool down before shutting off, turbo or not.

 

[Groo]

I think lack of timers is probably due to the libility of an engine that keeps running for 5-15min after you shut it down..........

We use to install aftermarket timers when we added turbos or heavily modified turbo cars.

Newer OEM turbos are pretty good about handling immediate shutdowns, water cooling and ball bearings help a lot. Turbo technology has come a long way, even in the last few years.

That being said I always give my cars/equipment at least a few min of cool down before shutting off, turbo or not.

5 minutes is probably a bit excessive.
Some tractors have a fuel shut-off and a key kill option, so that wold be less liability rather than more, since there would be a way to imediately kill the engine if needed.

 

[TMGT]

5 minutes is probably a bit excessive.
Some tractors have a fuel shut-off and a key kill option, so that wold be less liability rather than more, since there would be a way to imediately kill the engine if needed.

Libility is based on idiot proofing, yes a bypass could be added for immediate shutdown. I've seen equipment/cars equipped with factory timers, usually high end specialty equipment, some were basic time based and some were feedback that looked at different parameters for shutdown time.

Longest I can remember seemed to be about 10min, that was after a long heavy full load run with not downtime before shutdown.

I wouldn't be afraid of a 30+ year old turbo engine, like anything proper maintenence and it'll last.

 

[TractorGuy]

I put together some engine specs on my series backhoe you might find interesting. Note the 4 different engines are very similar with the 575E, 655E, and 675E being identical in displacement and compression ratios. The turbo 575E has the same HP as the NA 655E with a little more torque.

The shutdown procedure in my operator's manual says to idle the engine down to 1000 RPMs for two minutes before turning it off.

 

[duwem]

The motor may only be turning at 3K rpm but the turbo may be spinning at 15K rpm.

Make that 50-150k

No one has mentioned one engine is a reputable Yanmar brand and the other is a ding dang dong brand (never heard of whatever it is)....

 

[TMGT]

Make that 50-150k

No one has mentioned one engine is a reputable Yanmar brand and the other is a ding dang dong brand (never heard of whatever it is)....

Daedong is a reputable engine, it's the parent company name for Kioti and has been manufacturing engines/equipment since the 50's I believe. Their engines have been used in various equipment just like Yanmar, Kubota, Isuzu etc.

I wouldn't be afraid of its reliability.