My dealer advised against SUDT

Sully2 · Dec 1, 2005

( BTW, Kubota does not spec any engine oil for their engines and never has.
)

What exactly does THAT mean? You mean they dont specify any BRAND..or any particular WEIGHT..or ???

IH3444 · Dec 1, 2005

SkyPup, you've brought up a topic that I guess I should post a new thread for, but here goes seeing that you are so very knowlegdeable in so many areas. Why doesn't our extremely well made diesel engines have hydraulic lifters. Many a fine diesel automobile have them. Volkswagen, and Mercedes come to mind. My NH TC48DA shop manual says to check valve clearance at 600 hours. I was a bit flabbergassed, assuming that the engine would have come equiped with hydraulic lifters. Just thoughts.......

SkyPup · Dec 1, 2005

( ( BTW, Kubota does not spec any engine oil for their engines and never has.
)

What exactly does THAT mean? You mean they dont specify any BRAND..or any particular WEIGHT..or ??? )

It means exactly what it says, they only spec the hydraulic transmission fluids required for their equipment.

For further information, please refer to the SAE Technical Paper Series from the International Trends and Developments in Power Fluid for Off-Highway Operation Applications, entitled "Development of High Performance Transmission/Hydraulic Fluid (KUBOTA SUPER-UDT) Establishing the Specification and New Test Method by Nobushige Ichikawa and Tsunejiryo Seno, Senior Lubrication Engineers, Kubota Tractor Corporation, it contains the complete specs on the develoment of the Super-UDT hydraulic fluid for Kubota's new GST trannys, HST trannys, and their hydraulic equipment.

SkyPup · Dec 1, 2005

Here is a real good reason to use SUDT instead of a UDT rated hydraulic fluid in your Kubota HST, GST, and hydraulic pumps! /forums/images/graemlins/blush.gif

That makes it extremely easy to understand why Kubota put their special SUDT in my L-39 TLB with 23 gallons per minute of hydraulic flow!!! /forums/images/graemlins/grin.gif

SkyPup · Dec 1, 2005

( SkyPup, you've brought up a topic that I guess I should post a new thread for, but here goes seeing that you are so very knowlegdeable in so many areas. Why doesn't our extremely well made diesel engines have hydraulic lifters. Many a fine diesel automobile have them. Volkswagen, and Mercedes come to mind. My NH TC48DA shop manual says to check valve clearance at 600 hours. I was a bit flabbergassed, assuming that the engine would have come equiped with hydraulic lifters. Just thoughts....... )

I am not certain about that, but the VW & Mercedes have overhead cams with much more sophisticated fuel injection equipment (common rail, pump duse unit injectors, peizoelectric injectors, all at much high injection pressures, etc.) for much higher rpm operation.

I would guess that it has something to due with the cam grind and how steep the lobes are, how stiff the springs are, duration of the cam and total amount of lift.

Diesel tractor engines are low speed low horsepower diesels comparatively speaking to high output modern passenger car diesels, so I would imagine the air flow characteristics of the tractor engine combustion chambers are totally aimed at a different mode of output, ie. milder cam profile so not max lift for max flow at high rpms but probably longer duration to get more air into the combustion chamber prior to the end of injection and ignition before top dead center.

Sully2 · Dec 1, 2005

(
What exactly does THAT mean? You mean they dont specify any BRAND..or any particular WEIGHT..or ??? )

It means exactly what it says, they only spec the hydraulic transmission fluids required for their equipment.

)

oh! I get it now. Someone asks a question and they get techinical jargon thrown in their face. Okie doke! Gotcha!!

SkyPup · Dec 1, 2005

( (
What exactly does THAT mean? You mean they dont specify any BRAND..or any particular WEIGHT..or ??? )

It means exactly what it says, they only spec the hydraulic transmission fluids required for their equipment.

)

oh! I get it now. Someone asks a question and they get techinical jargon thrown in their face. Okie doke! Gotcha!! )

No, it simply means you need to reread the orignal post again since it contains the answer to your question in it. /forums/images/graemlins/wink.gif

HGM · Dec 1, 2005

SkyPup,
I'm going to join your side on the hydraulic fluids. They are exposed to much greater pressures and temperature fluctuations than motor oil. Synthetics would be a good idea in this case. Likely the real reason they were designed in my opinion.

IH3444 · Dec 2, 2005

SkyPup, thanks for the response. I thought with the milder cam in a diesel it would have been easy to install the hydraulic lifters. Maybe that tech has not caught up with tractor engines. As far as your Kubota valve clearance goes, I don't know, but I'm sure that info is easy to find. The clearance for the valves on my IH3444 BD154 engine is 0.020" for both intake and exhaust. They were very loud at that setting, so I set'em down to 0.018". The rocker arms need to be removed and refinished on the end that contacts the valve stem, but I haven't done that yet. If I ever pull the head, that will get done also. I refinished the rocker ends that ride on my Porsche 911 engine, they weren't really worn much, but I was installing some Vopper profile cams into a fresh rebuild. Always a pleasure reading your post. Thanks for your time. I also found with the oil pressure, and oil temp gauges in several application that with synthetics the oil pressure didn't spike the pressure gauge on cold start ups, and held higher pressure after oil was hot. Also the temp never went over 210F, where as under hard use the temp with regular dino the temp sometimes exceeded 250F. Yipes!! Just an obsevation. You graph shows the increased flow at start up due to the improved properties of synthetics. /forums/images/graemlins/grin.gif

SkyPup · Dec 2, 2005

Modern high speed direct injection turbodiesel engines (HSDI) are putting out 100HP/liter displacement, something simply unheard of and unbelieveable only ten years ago! Many gasoline engines in commerical production cannot even match that! /forums/images/graemlins/blush.gif

Tractor IDI engines are only putting out around 15-20HP/liter, so obivously allot less airflow going into the combustion chambers on the low rpm tractor design heads. The Ricardo IDI combustion chamber has not changed much over the last fifty years, but the new DI designs have been mutating like lightning every year with new metallurgy, especially the cast graphite sintered engine block and head to encapsulate the extreme combustion chamber pressures experienced in modern HSDI designs such as Mercedes, Volkswagen, Audi, and Peugot.