Temperature of the Oil in the tank?

lcrken · Jan 3, 2013

hobot said:
Hm, can't find where I got idea to set up for assumed 280' F temp form but do appreciate knowing that racer oil tanks over boiling ain't that big a deal.

Maybe from my post on first page of this thread? Just remember, that's worst case, hot day, fast track, iron cylinder, race engine, no oil cooler temperature. For what it's worth, the oil was Kendall GT 40W. That's what Axtell recommended back in the '70s, before we had all the modern synthetics, and it was pretty popular with the dirt track crowd.

Ken

john robert bould · Jan 3, 2013

Back to the original post,
Oil temperature in the tank, What interests me is where the oil loose's the heat?
Oil is very reluctant to give up heat, as the engine as a much larger surface area and subjected to wind/air flow i am thinking the oil cools in the crankcase..the hidden oil tank has very little cooling effect.
Will adding more oil help? I personaly think not...high flow mayby?
What do you racers think?

Dances with Shrapnel · Jan 3, 2013

I tend to agree that a considerable amount of heat from the oil is lost through the crank cases on a Norton twin; the aluminum cases have good thermal conductivity, plenty of surface area and normally right out in the cool air. The oil tank surface is another major path for heat loss.

Increasing oil quantity does bring down oil temperature. As an example, for a given unit of time, if you double the oil quantity you 1.) double the cumulative time any given unit of oil has to cool in the tank and elsewhere and 2.) reduce by half, the cumulative time any given unit of oil will spend in an area accumulating heat energy. In theory you are removing heat (energy) from the system at the same rate in either scenario, the difference is that oil will be a bit cooler when delivered to the engine parts if you double the reservoir volume.

This is a typical thermodynamic problem where you look at heat flow rate as it relates to mass flow rate and residence time.

What do you think would happen to oil temperature if you ran a Commando hard with say 1-1/2 or even 1 quart of oil?

john robert bould · Jan 3, 2013

Running with low oil?
Not a simple question to answer, does a small amount of oil take less to cool? yes it will. But a small amount heats up quicker..but as we have read a commando engine relies more on air flow over the engine rather than oil cooling....a tipical 10 degrees less if the tank is 1/2 full or topped up.
Two strokes dont have oil tanks or oil to cool, just bigger fins. will a bigger finned head and cylinder produce a better cooling solution?

Nortiboy · Jan 3, 2013

john robert bould said:
Oil is very reluctant to give up heat, as the engine as a much larger surface area and subjected to wind/air flow quote]

The coolest running commando motor I have is a 750 MkV using both combat and an oversize 850 style (open) breather, plus larger holes through the timing side. Heaps of air pumping in and out. After a 2 hour run in 120f (47c) air, at about 4500 rpm I can dip my finger in the tank oil. Another factor in this motor is Mobil 1 V Twin seems to run cooler than non-synthetic oils.

Airflow is the only coolant we have so ambient air getting thrashed around inside the motor would certainly help strip some heat.

Dances with Shrapnel · Jan 3, 2013

john robert bould said:
Running with low oil?

Well of course it is not a recommendation but cited to make a point.

john robert bould said:
Not a simple question to answer,

Well yes, it is all too simple. What is difficult to answer is "How much cooler"

john robert bould said:
does a small amount of oil take less to cool? yes it will. But a small amount heats up quicker

Your above statement is muddying up the waters. You ask and then answer but without context; less time, less energy transfer, less what?

john robert bould said:
but as we have read a commando engine relies more on air flow over the engine rather than oil cooling....a tipical 10 degrees less if the tank is 1/2 full or topped up.
Two strokes dont have oil tanks or oil to cool, just bigger fins. will a bigger finned head and cylinder produce a better cooling solution?

Again, not in context with your original question. What you present above is a discussion on ways to keep a Norton twin cooler. Of course bigger finned head will keep things cooler.

What I am saying is that for a given engine load, speed etc, your oil tank temps will be lower with more oil rather than less. Simply stated, the more time the oil resides in a tank (cooling time) in proportion to being rifled through the engine picking up heat (heating time), the cooler that oil will be. Furthermore, when you start with a cooler oil feed the temp rise (delta) should remain constant after passing through the motor but will be at a lower temperature when it comes out; it still carries the same thermal energy at the same rate.

On the other hand, a hotter oil tank will shed thermal energy at a higher rate than a cooler oil tank. That is where the complexity is when trying to answer "How much". Again, for illustration purposes only to understand the effects oil capacity (volume) has on temperature, if you ran your Commando hard with say only 1 quart of oil, it would heat up much faster than with the recommended 2.5 quarts and the oil would be considerably hotter under equally steady state conditions.

more oil = cooler.

Nortiboy · Jan 3, 2013

more oil = cooler.[/quote]

Yes.

More oil see's more tank wall to dissipate heat.

More oil takes longer to heat up and cool down.

Matt Spencer · Jan 3, 2013

Tech . heat dissapation ; http://www.lmr.com.br/httpdocs/catalogo ... chap_5.pdf

john robert bould · Jan 3, 2013

I have no equipment to measure the oil tanks heat loss..have you?

uote="Dances with Shrapnel"]

john robert bould said:
Running with low oil?

Well of course it is not a recommendation but cited to make a point.

john robert bould said:
Not a simple question to answer,

Well yes, it is all too simple. What is difficult to answer is "How much cooler"

john robert bould said:
does a small amount of oil take less to cool? yes it will. But a small amount heats up quicker

Your above statement is muddying up the waters. You ask and then answer but without context; less time, less energy transfer, less what?

john robert bould said:
but as we have read a commando engine relies more on air flow over the engine rather than oil cooling....a tipical 10 degrees less if the tank is 1/2 full or topped up.
Two strokes dont have oil tanks or oil to cool, just bigger fins. will a bigger finned head and cylinder produce a better cooling solution?

Again, not in context with your original question. What you present above is a discussion on ways to keep a Norton twin cooler. Of course bigger finned head will keep things cooler.

What I am saying is that for a given engine load, speed etc, your oil tank temps will be lower with more oil rather than less. Simply stated, the more time the oil resides in a tank (cooling time) in proportion to being rifled through the engine picking up heat (heating time), the cooler that oil will be. Furthermore, when you start with a cooler oil feed the temp rise (delta) should remain constant after passing through the motor but will be at a lower temperature when it comes out; it still carries the same thermal energy at the same rate.

On the other hand, a hotter oil tank will shed thermal energy at a higher rate than a cooler oil tank. That is where the complexity is when trying to answer "How much". Again, for illustration purposes only to understand the effects oil capacity (volume) has on temperature, if you ran your Commando hard with say only 1 quart of oil, it would heat up much faster than with the recommended 2.5 quarts and the oil would be considerably hotter under equally steady state conditions.

more oil = cooler.[/quote]

Hobot · Jan 4, 2013

Here's another piece of wood in the stove to clear some smoke. Its a cooking principle to use oil to conduct heat into food rather than just the weight bearing contacts, I don't think engine cases get boiling hot from combustion heat so far away, so I want to believe oil could cool off via the time spent splashing in crankcase. I've read @ 6000 rpm pumps ~13 gal / hr, 10 to the crank and 3 to the head. So a bit more than 1/3 the oil in case is head oil rather over boiling hot.

Shrapnel list is accurate but for his haste on below effect on doubling oil hauled around.

2.) reduce by half, the cumulative time any given unit of oil will spend in an area accumulating heat energy.

Only doubling the oil flow and drain would reduce the oil time in contact with stuff - regardless of the total volume lugged around. At any set flow rate, 2x's the oil amount would take twice as long for all the oil to contact stuff.

One tiny point missed so far is increasing the oil volume also increases the amount of surface it can conduct heat through. As covered, main reason more oil helps cool is there's more of it just sitting around cooling off before going back to work. More oil help stablize temp swings somewhat too. Drouin's users were recommended to fit an oil cooler to help with their extra heat. I wonder how long any one can hang on to much Drouin throttle at one go.
================================================================================

This ain't academic to Peel so I've tried to put some numbers around it.

Ms Peel may need to shed 830,000 btu/min vs 250,000 of regular Combat. That's like 66% or 2/3'rds more heat to radiate than a hot factory Combat head.

Please check my math as able or willing.
post100789.html?hilit=btu

Hobot · Jan 4, 2013

Nano texturing for heat conduction may be in some Norton's future. Splashing droplets work the best it says.
http://phys.org/news/2013-01-droplets.html

Dances with Shrapnel · Jan 4, 2013

john robert bould said:
I have no equipment to measure the oil tanks heat loss..have you?

Yes, I do.

It is the gray matter between my ears. A little thermodynamics, a little math, a little intuition, a little logic and VOILA!

Not exactly equipment but when I add more oil in the tank, the oil in the tank stays cooler....hmmmm. What else could it be?

The extra oil for more cooling is mentioned in

broken link removed courtesy of Matt Spencer.

Where a splash system such as a rear differential on a car keeps cool by adequate volume and adequate surface area.

Dances with Shrapnel · Jan 4, 2013

hobot said:
Shrapnel list is accurate but for his haste on below effect on doubling oil hauled around.

2.) reduce by half, the cumulative time any given unit of oil will spend in an area accumulating heat energy.

Click to expand...

In hobot's haste he has missed what I wrote when I stated "cumulative time".

To illustrate this If you could isolate and move each cubic centimeter of oil sequentially through the engine (like on a conveyor belt) and the oil flow rate remains the same (conveyor belt speed) then if you double the number of packages of oil available to handle, the cumulative time for each package is halved. Furthermore, each package now has twice the time to cool off. This is the simple math.

Where it gets a little more complicated is that the overall system is now cooler. With a lower temperature the heat energy transfer rate slows down a bit. This is a related rate problem but somewhat academic when you can observe that after adding oil the system is cooler.

In your instance hobot with the Drouin, it would be interesting to see the relative surface area of your oil in frame as compared to the typical Commando oil tank. I would still go with an oil cooler.

Dances with Shrapnel · Jan 4, 2013

Matt Spencer said:
Tech . heat dissapation ; broken link removed

Thanks again Matt. Interesting graph on page 125 of the referenced article pertaining to moisture content and "Relative (factor) Life".

So when someone suggests putting in an oil cooler without a thermostat this is what my concern/opinion is; not getting the oil up to proper temperature to drive off moisture will likely happen more often and cause more damage to the oil and motor than an overheated oil excursion. In my opinion it is similar to the emotional judgement in avoiding commercial air travel and using car travel because it is safer when it is not.

john robert bould · Jan 4, 2013

[

So, basicly you simply guess? What was the start temp, how much did you add,how many miles did you do before a second record?
Did you drain off some oil.or simply top up. I guess you felt the tank side and thought ..yep that feels cooler....Not really Thermodynamic's is it?

uote="Dances with Shrapnel"]

john robert bould said:
I have no equipment to measure the oil tanks heat loss..have you?

Yes, I do.

It is the gray matter between my ears. A little thermodynamics, a little math, a little intuition, a little logic and VOILA!

Not exactly equipment but when I add more oil in the tank, the oil in the tank stays cooler....hmmmm. What else could it be?

The extra oil for more cooling is mentioned in

broken link removed courtesy of Matt Spencer.

Where a splash system such as a rear differential on a car keeps cool by adequate volume and adequate surface area.[/quote]

Hobot · Jan 4, 2013

Engine Shredder, what we have here is simply a failure to communicate.

To illustrate this If you could isolate and move each cubic centimeter of oil sequentially through the engine (like on a conveyor belt) and the oil flow rate remains the same (conveyor belt speed) then if you double the number of packages of oil available to handle, the cumulative time for each package is halved. Furthermore, each package now has twice the time to cool off. This is the simple math.

We-me know you know what you're talking about, just ain't conveyed your above point correctly yet. One oil unit at a time in single file flow though a path will not change flow rate, no matter how many extra units of oil waiting in line. If you increase oil head height then yes, but not if oil tank enlarged so oil level the same just more of it, cooling off waiting. To double the flow the belt must be sped up 2x's, like higher oil pressure might or 2 units of oil must be carried in the same space [stacked on a top one another aka on wider belt or in bigger pipe. Oil level in tank don't change flow through engine very much to matter. Its true that cooler oil and engine radiate less heat, but such a small amount issue in our size engines can be ignored unless this cooler temp to dump also prevents water cook off.

The more I learn the hotter I want the oil in the tank til pretty nearly boiling for a while, especially if I ain't going be riding it again next day. I've got more oil cooling options already on hand than a parking lot of cafe's or a race pit full of Norton, up to a Corvette size, but will hold off till Peel shows me what she wants. May not be able to live with Drouin so Peel already set up for easy addition or removal of a cooler - hung aligned out of bike air flow but fully exposed to the outward air spray of tire and rear spokes blasts. I've see all air flows into, through, up down and around a Commando + pilot and tell ya most the engine hot air slaps right back where the air box or carb throats open, which is not occurring on dyno runs so might be worth keepping in mind to those pressing their luck. Read on and maybe come on in closer from the cold and sit a spell nearer hobot's oil heated camp.

Water world bad juju issues and many solutions to be aware of,epsecially only moderately heated oil.
http://www.machinerylubrication.com/Rea ... ter-in-oil

Experiments have shown the protection provided by zinc dialkyldithiophosphate (ZDDP), a common anti-wear additive and antioxidant, to be destroyed by as little as one drop of water in a gallon of oil, with oil temperature above 180 degrees F(82 degrees C).

The deleterious effects of water on the fatigue life of rolling element bearings is widely documented. According to SKF, "It is well-known that free water in lubricating oil decreases the life of rolling element bearings by ten to more than a hundred times...

much more here
http://www.maintenanceresources.com/ref ... s/oa-m.htm

Dances with Shrapnel · Jan 4, 2013

john robert bould said:
So, basicly you simply guess? What was the start temp, how much did you add,how many miles did you do before a second record?
Did you drain off some oil.or simply top up. I guess you felt the tank side and thought ..yep that feels cooler....Not really Thermodynamic's is it?

I see you ask a lot of questions and guess a lot.

So I am guilty of not stating the obvious; I use a thermometer, both candy (immersion) thermometer and indirect on occasion.

No guessing but glad you asked.

"What was the start temp,"

too hot. I've seen 10-15 degree drops on occasions from excess of 230 F.

"how much did you add,"

enough. This can vary but usually .5 to 1.0 quarts. These are race bikes.

"how many miles did you do before a second record?"

Laps man, laps. Usually practices are several laps so also dependent upon track size but a fair amount of WOT for 6 to 10 miles in a session. And yes, lap times are usually consistent and oil temperatures are consistent. :roll:

"Did you drain off some oil.or simply top up."

I add. Sometimes if cold conditions I'll keep the tank a little low for morning practices if it is cool out. The
bikes get worked over so much after a race weekend that it is usually a matter of refilling the tanks.

Am I correct to assume that you do not believe extra oil capacity reduces the temperature of the oil? Is that what this is all about? Is that your position?

I have offered some explanations and it sounds like you do not like them, do not understand them or simply do not accept them. If mass and energy (heat) flow is not Thermodynamics, then what is it?

What is your position on this? How do you explain what I am seeing. How do you reconcile with what was explained in the referenced article above?

I'll certainly eat crow if I am wrong here. Is your position that greater oil quantity has no impact on tank temperature? Is your position that greater oil quantity increases tank temperature?

Just curious. What am I missing. Bring something to this table.

Dances with Shrapnel · Jan 4, 2013

hobot said:
Engine Shredder, what we have here is simply a failure to communicate.

Dances with Shrapnel said:

To illustrate this If you could isolate and move each cubic centimeter of oil sequentially through the engine (like on a conveyor belt) and the oil flow rate remains the same (conveyor belt speed) then if you double the number of packages of oil available to handle, the cumulative time for each package is halved. Furthermore, each package now has twice the time to cool off. This is the simple math.

Click to expand...

We-me know you know what you're talking about, just ain't conveyed your above point correctly yet. One oil unit at a time in single file flow though a path will not change flow rate, no matter how many extra units of oil waiting in line. If you increase oil head height then yes, but not if oil tank enlarged so oil level the same just more of it, cooling off waiting. To double the flow the belt must be sped up 2x's, like higher oil pressure might or 2 units of oil must be carried in the same space [stacked on a top one another aka on wider belt or in bigger pipe.

Well I think you have got it and I understand what you are trying to say about increased flow rate which was never an issue. The point I was trying to illustrate was that with increased capacity for a given flow rate, a unit of oil has more time to loose heat energy. In other words, double the oil volume and those "packages" of oil will spend twice as much time cooling off.

When you get your bike together with the Drouin, start making observations (thermometer) of oil temperature as well as indirects temp readings on the cylinder head and elsewhere so you have a good sense of what is really happening.

john robert bould · Jan 5, 2013

I agree with your point...now i realize your aplication.....A race bike constant 6000 rpm [nealy] and 60-120 wind ,plus a bigger alloy tank?
Compared to a sadate road bike...with a hidden steel tank..
I still stand by my statement..a Road use Steel oil tank will remove little heat.... I didnt say NONE.
One member stated Commando's are AIR cooled ...Not OIL cooled

Do we agree that race bikes are a differant beast? Placing a high speed fan [100mph wind] draft in front of a oil tank will considerbly reduce the tank surface temp..
Totally agree. Cover it up and have little wind......?

Dances with Shrapnel said:
hobot said:

Engine Shredder, what we have here is simply a failure to communicate.

Dances with Shrapnel said:

To illustrate this If you could isolate and move each cubic centimeter of oil sequentially through the engine (like on a conveyor belt) and the oil flow rate remains the same (conveyor belt speed) then if you double the number of packages of oil available to handle, the cumulative time for each package is halved. Furthermore, each package now has twice the time to cool off. This is the simple math.

Click to expand...

We-me know you know what you're talking about, just ain't conveyed your above point correctly yet. One oil unit at a time in single file flow though a path will not change flow rate, no matter how many extra units of oil waiting in line. If you increase oil head height then yes, but not if oil tank enlarged so oil level the same just more of it, cooling off waiting. To double the flow the belt must be sped up 2x's, like higher oil pressure might or 2 units of oil must be carried in the same space [stacked on a top one another aka on wider belt or in bigger pipe.

Click to expand...

Well I think you have got it and I understand what you are trying to say about increased flow rate which was never an issue. The point I was trying to illustrate was that with increased capacity for a given flow rate, a unit of oil has more time to loose heat energy. In other words, double the oil volume and those "packages" of oil will spend twice as much time cooling off.

When you get your bike together with the Drouin, start making observations (thermometer) of oil temperature as well as indirects temp readings on the cylinder head and elsewhere so you have a good sense of what is really happening.

Hobot · Jan 5, 2013

Duh, everyone's got it about heat flow into environment, just how much and where is the mystery, except we know if takes rather extreme conditions to have to worry about too cold, like the fella in Alaska with a 7 mile work trip with milky oil or over heated like Goldwater's loaded down run that turned oil into thin brown soup on 200 mile hot ride. Peel's frame and hoses and small filter should hold almost 2 quarts max. Her spine is tapped at rear plate for a temp sendor bung, there oil drains out a 3/8" steel tube about 5" long that fills the RH frame tube with a hose off to pump at top of Z plate level. I've put a failsafe ball valve there but think I've talked my self out of it for the wet sump benefits. Oil return goes into a 6"x 2" Al canister filter then check valve into LH frame tube about mid level of Z plate then into the spine at stem level via 4" long steel tube silver solder snug to side of stem. Ain't done surface area calc's but should have at least twice oil tank surface exposed to air flow. I bought Al foil covered foam insulation to wrap around spine just in case Peel don't show nearly boiling temps at rear of spine. I may paste on those liquid crystal thermometer strips to see how oil cools along the way.

I agree a steel blocky shaped oil tank under cover ain't radiating heat very efficiently but certainly enough to live with unless in extreme conditions. When I was more ignorant I'd cut air slots in front of Peels IS side cover but think that mostly just let in more insulating dust layer than extra cooling. Wesley has cut a lightening bolt shape in his '71 cover, mostly because of boredom and style to look though to see black flank of tank. I've nixed idea to install sensor in the head metal like Comstock, sense he's already given us the 500' F the metal gets too after 20 min still idle or 20 miles over the ton.

What I've spend most time looking up is how to cool Peel mixture intake which is more important than oil temp to detonation.

Temperature of the Oil in the tank?

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