Starting Procedure

[poldies4]

I am impressed! There is nothing like some hard data to help people make a decision. I was suprised by the results. They also give me some comfort in not switching to 10W-40 in the winter.
Thanks for the using your "laboratory" to shed some light on this question.
By the way, my B7800 manual says "set the throttle lever to about 1/2 way." It says nothing about RPMs.

Exactly, half throttle is not half rpm. I tried many variations this week, and found the best for my tractor(according to how it sounded) was half or so throttle until start, then ease it back to 14-1500 to warm up. Sounds real nice at those levels. That's my for what it is worth

 

[TripleR]

Yesterday in preparation for the coming storms I went out with my wife to hook up to the FEL on my BX2660 and move stuff under roof. I took my glasses as unlike my other tractors the BX has very small digital tach which I cannot read without glasses. I cranked it up the way I usually do; nothing precise. The engine sounded "about right" to me. I put my glasses on and to my surprise I was turning 2350 RPM's. It did not "sound" too fast to me, but I dropped it down to 1500. I must interject that ALL these engines sound too fast especially my John Deere 425 gas and even my L5030 when running it at the PTO speed; too many years farming with the old iron I guess.

My L5030 "half throttle" start up is 1300-1500 RPM's, but it has an easily readable tach, so that might have influenced my perception of "half throttle".

This has been a very interesting thread and just goes to show that no matter how long you have been operating machinery, it sure doesn't hurt to re-examine your operation at times; might just learn something. I am going to use my glasses to warm my BX up until I can get right around 1500 RPM's consistently; 2350 doesn't "sound" too fast to me, but saying it out loud sure does.

 

[kuboman]

IBNXE; I thank you for your time and effort put into your test. I don't want to dispute your findings but I do want to interject a few things. There are many oil passages in an engine that are very small. Small enough that a cold heavy oil will not flow through with any speed. Most oil pressure gauges take there reading quite often right at oil filter which is the first to get oil. So watching the oil light go out does not tell you much about the lubrication of the engine. Cam shafts and top end valve trains have very small oil passages and it is not unusual for cold heavy oil to take 90 seconds to get lubrication to those areas.
I realize most of your readers live in a part of the world that never experience minus 20F or even -40F. I do so I have done allot of research and read allot about cold weather engine treatment. Believe me when I say that if I used Kubotas engine starting procedure I would have been out of business years ago.

 

[ibnxe]

IBNXE; I thank you for your time and effort put into your test. I don't want to dispute your findings but I do want to interject a few things. There are many oil passages in an engine that are very small. Small enough that a cold heavy oil will not flow through with any speed. Most oil pressure gauges take there reading quite often right at oil filter which is the first to get oil. So watching the oil light go out does not tell you much about the lubrication of the engine. Cam shafts and top end valve trains have very small oil passages and it is not unusual for cold heavy oil to take 90 seconds to get lubrication to those areas.
I realize most of your readers live in a part of the world that never experience minus 20F or even -40F. I do so I have done allot of research and read allot about cold weather engine treatment. Believe me when I say that if I used Kubotas engine starting procedure I would have been out of business years ago.

Believe it or not, engine manufacturers design the size of these small oil passages to limit flow to certain areas of the engine. These smaller passages are typically to feed oil to the rocker arms and valves. Flow to these areas is limited, as to not exceed the rate that the oil can drain back to the crankcase sump. In the past, I have up-sized drilled oil passages, on blocks used for racing purposes to increase flow to these areas.

You haven't mentioned where you are from. Here in Puget Sound area of western Washington, it rarely gets much below freezing. In this area I can easily run the same grade of oil all year long.

 

[kuboman]

Believe it or not, engine manufacturers design the size of these small oil passages to limit flow to certain areas of the engine. These smaller passages are typically to feed oil to the rocker arms and valves. Flow to these areas is limited, as to not exceed the rate that the oil can drain back to the crankcase sump. In the past, I have up-sized drilled oil passages, on blocks used for racing purposes to increase flow to these areas.

You haven't mentioned where you are from. Here in Puget Sound area of western Washington, it rarely gets much below freezing. In this area I can easily run the same grade of oil all year long.

Limit yes not starve which is what happens with heavy oil at temperatures below its design.
I live in the northern prairies of Canada. I have seen many engines ruined by cold weather starts. People can do what ever they want. Engineers/manufactures are not always right with there recommendations.

 

[TripleR]

Seems like we might be straying a little and going from "starting procedure" to "starting procedure in extreme temperatures".

I would imagine that if I lived in the northern climes, it would be prudent to modify starting and operating procedures. I doubt that I would start anything without some type of preheating. Many years ago, I literally blew the oil filters off my cars by cranking them up without preheating.

 

[EE_Bota]

Seems like we might be straying a little and going from "starting procedure" to "starting procedure in extreme temperatures".

I would imagine that if I lived in the northern climes, it would be prudent to modify starting and operating procedures. I doubt that I would start anything without some type of preheating. Many years ago, I literally blew the oil filters off my cars by cranking them up without preheating.

In a previous job, I designed substation transformers. We had a standard manual that went out with all transformers. The only time I had to write a custom manual was for one that I designed for northern Alaska. In extreme cold, sometimes things are a bit different. That series of transformers would have destroyed themselves if they were started in the normal fashion.

In the part of the thread about what rpm is half throttle, I would have thought folks would report that "my tractor turns x rpm at half throttle." I am reasonably confident Kubota means "grab hold of that handle and move it somewhere close to the halfway point."

As for the gentleman that did the test with the oil pump: I was very impressed everything he said. He is sharp as a tack, and he knows what he is talking about, and that shines right through.

Most modern engines have a bypass in their filter in the event that they may somehow become clogged, but also to prevent them from simply blowing apart their shell. I have seen these shells fracture, but mostly, they will be pushed off of their threaded nipple until the rubber gasket looses its seal, and the oil spills out. I have seen this in hydraulics and in engines.

Also, it should be remembered that most modern engines have a oil pump relief valve that sets the maximum pressure that will be obtained, regardless of the temperature of the oil. Although pressure could get too low due to high oil temperature, or low pump rpm, it ought not get too high, regardless of temperature. If you believe your climate precludes this, then certainly you will need a gear drive tractor, not a hydrostatic one, since those reliefs would be likewise effected.

Some oil pumps can have difficulty establishing their prime once lost. Many pumps will lose their prime over time. High viscosity oil in a pickup tube makes it even harder. Starting at a lower rpm certainly does not help this situation. In this case, you are dealing with a pump that is pumping air, not oil. Once the air is displaced, and some vacuum is formed, and the oil finally gets up to the pump, then it begins to function as the reliable fixed displacement pump we all rely on.

If if you want to talk about a diesel, you can say they burn diesel, and they have high compression, and they have high injection pressures to compensate. BUT: beyond these common things, you must then specify WHICH diesel. A VW that can turn nearly 6000 rpm, a Kubota that can turn 3200 rpm, or a big industrial that can turn 900 rpm? Each is different, and each has their own manual, which will tell you many things, including how to start it.

My BX has a fixed displacement lift pump that acts as a pilot pump for the hydrostatic unit as well. It ought to warm up a bit before it is put to work. If will warm up much faster at half throttle than at idle, since few if any of the reliefs are being challenged at idle. Anytime a hydraulic pressure drops with an actual flow of fluid and this happens while not shifting a heavy load, that power is going directly to heat. Even so, it still takes a while.