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Author Topic: 4104 Radiator Shutters  (Read 4364 times)
gus
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« on: July 18, 2006, 07:01:15 PM »

I just recently discovered that my 4104 radiator shutters work fine. Most of the almost one year I've owned it I thought the shutters were rusted open because it never ran higher than 140-150 on flat ground. It ran 130 on cold days in April in the Rockies. Sometimes it would go as high as 180-190 on long grades but go right back down to 130-140 downhill.

I just finished a 1300 mile trip in mostly 95+ degree/100+ % humidity and they worked perfectly. The heat gage stayed between 178 and 188 depending of the conditions. Yesterday, one of our hottest so far, it stayed right on 178 for about 400 miles. I guessed that the shutters were completely open all this time because the other three days the temp fluctuated between 182 - 188 and 185-192, it was never completely stable at any one temp.

Call me a bit weird but I get a kick out of seeing these ancient systems work just as advertised.

They didn't work before because the drain valve at the shutter air valve leaked and the air had been turned off!!
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PD4107-152
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Stan
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« Reply #1 on: July 19, 2006, 05:42:31 AM »

gusc: The radiator shutters are not there to control the engine temperature. They open when the temperature goes above the  shutterstat  set point. Your engine should never be run at 130*. If your temperature gauge is working properly, the engine thermostat must be stuck open or someone has removed it. You can test the gauge by putting the sender in water and heating the water. Be sure to connect the sender body to ground. If the gauge is correct, then pull the themostat and if it is stuck open, jist replace it with the recommended temperature (180* - 185*)
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gus
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« Reply #2 on: July 19, 2006, 02:39:22 PM »

Stan,

Thanks for the info. I assumed the shutters controlled the temp and the thermostat sent water only through the block until it got warm enough to use the radiator.

However it works, I'm happy that it is finally running at 180+. I knew 130 was too cold, 150 is too cold, but I wasn't sure what to do to make it run warmer when I first got it. This is my first bus.

It won't surprise me to find that the thermostat is missing.

I don't think the gage is off because it is showing about what I would expect for the conditions.
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PD4107-152
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DrivingMissLazy
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« Reply #3 on: July 19, 2006, 04:33:45 PM »

What is their purpose then?
Richard
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The radiator shutters are not there to control the engine temperature
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« Reply #4 on: July 19, 2006, 07:05:08 PM »

Richard,

See Stan's post above.
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DrivingMissLazy
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« Reply #5 on: July 20, 2006, 03:34:22 AM »

I always thought they were to close in cold weather to reduce the air flow across the radiator and allow the engine to warm up or to keep it warm, thereby controlling the engine temperatrure, but what do I know? LOL
Richard


Richard,

See Stan's post above.
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« Reply #6 on: July 20, 2006, 06:04:15 AM »

Richard: Like you I am writing from memory (not good) but I think the DD manual give specific temperature spreads for the thermostat, fan and finally the shutters. The shutters are not to control the emgine temperature, that is the function of the thermostat. The shutters prevent engine overheating when the thermostat is wide open and thee is not enough cooling in the radiator without more airflow.

I expect that the shutters do stop some cold air cooling of the engine during warm up, but thrucks with thermostatic fans also use shutters so there is no forced air circulation until the fan cuts in at almost wide open thermostat. IIRC there is some overlap of the temperature controllers so that the fan cuts in before the the themostat is wide open. On a MCI  bus with a constant  fan, the dampers should open and allow air flow over the engine before the shutters open. HTH
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Frank @ TX
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« Reply #7 on: July 20, 2006, 11:42:38 AM »

What is their purpose then?
Richard
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The radiator shutters are not there to control the engine temperature

I heard the shutters are there when the bus was a bus and carried lots of people.
When the interior heaters were on full the engine would drop in temp with the rads and inside heat.
So the shutters would close and block off the rads, all available heat to the people.
The engine thermostats control the engine temp.
I have an AquaHot for interior heat so I removed the shutters for MORE air flow to the rads.
Frank
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Stan
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« Reply #8 on: July 20, 2006, 12:17:45 PM »

Frank: A local bus company doing construction crew transportation had complaintsd of cold feet in their 4104's in -40* weather. They installed Webasto heaters for supplemental heat. In buses with a 8V71 engine they put spray foam on the underside of the floor and that was suffiicient to stop the union complaints. I bought a MC-5 from this company with the sprayed in foam and wondered how a worker dressed to work outside was too cold inside a heated bus. You are correct that in very cold weather the heater core can cool down a 6-71 engine.

I am suprised nobody noticed the error in my previous post. The temperature contol sequence is thermostat, shutters and then fan. On a truck, the fan only comes on when ram air through the rad is not sufficient.
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gus
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« Reply #9 on: July 21, 2006, 01:16:56 PM »

The bottom line for me is that the temp stays where it belongs in this miserably hot weather and there is no doubt in my mind that it will run at the correct temp in cold weather.

What more could one ask?

I don't think that the absence of shutters improves cooling any because the shutters are at 90 deg to the radiator, they might even improve cooling by smoothing out the air flow.
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Stan
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« Reply #10 on: July 21, 2006, 02:28:37 PM »

gusc: I re-read your original post and I think you still have a temperature control problem. Running hard on a very hot day will have the engine thermostat wide open and the radiator shutters open. Iif you are lucky, and have a good clean cooling system, the temperature will stay in the 180* range under those conditions. This means that you are at the maximum capacity of your cooling system.

 If you have not changed anything except turn on the air to the shutter control, your engine will not come up to the proper operating  temperature on a cooler day. That is the way I understand your first post, and I think you have an engine thermostat problem.

 When the engine thermostat is closed, water dosen't circulate through the radiator and a working engine transfesr a lot of heat into the water in the block. If the thermostat stays closed, the water will boil. If it opens (as a good thermostat will) the water starts to circulate through the radiator before it reaches the thermostat set point. If the thermostat is set for 180* it will start to open about 170* and when the temperature reaches 180* it will modulate to hold it at 180*. Overheating occurs when it is wide open and the temperature continues to rise in the engine and the radiiator does not provide sufficient cooling to the circulating water. HTH If it  is clear as mud to you, ask more questions and I will try and help.
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Burgermeister
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« Reply #11 on: July 22, 2006, 07:44:27 AM »

I wish to add two points to Stan's post.

If temp is stabilized at 180 deg (180 deg Thermostat) and all else being equal and properly maintained,  there still is more capacity in the system as it should allow for a certain amount of coolant aeration and the need to  cope with the potential for a certain amount of exhaust gases leaking into the cooling system.  The fact that sustained temps at 195* or the planned shutdown of 205* means there is more capacity in the system. But just because it's there doesn't mean that it's a good idea to venture in to these areas of the perfomance envelope.

Second,  if the thermostat is closed, the bypass hose provides for a minimal, but necessary, circulation of water within the block.  Otherwise, if the water circulation was stopped, it could get real hot at the cylinder heads and the thermostat would never ( or much too late) find out about it.

These points are anecdotal and don't change Stan's post in any significant regard.  The relationship between the shutters and maintaining coolant temp secondary to maintaining engine temp could be restated in a more together or cogent fashion.

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DrivingMissLazy
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« Reply #12 on: July 22, 2006, 10:58:08 AM »

Marc, I have to agree with your last statement. To me, temperature control is controlling both low and high temperature.
Richard


These points are anecdotal and don't change Stan's post in any significant regard.  The relationship between the shutters and maintaining coolant temp secondary to maintaining engine temp could be restated in a more together or cogent fashion.


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« Reply #13 on: July 23, 2006, 06:02:51 AM »

Richard: Different methods have been used to control the low temperature. The engine thermostat does a fairly good job of bringing the engine up to operating temperature quickly if there is suffiecient load on the engine. Probably the ideal way is to preheat the engine coolant to 180* before starting. This is easily done with a propane fired engine coolant heater or a Webasto type heater.

If you want to maintain some fixed amount or temperature spread between the top and bottom of the engine, when running,  then you need a pretty exotic controller. Our older model buses were built when industriial pneumatic temperature controllers were common but the price and complexity of the system was prohibitive. With microprocessors on a DDEC style engine it is more feasible.

Many of the older engines used a primitive form of delta T control by using variable pitch fans, fluid drive fans and on-off fan control. They all had the same limitation in that they were operated by an on-off temperature sense switch which could not anticipate a change or determine the rate of change, or indeed even the amount of change. A convential shutterstat only switches when the temperature is either above or below the setpoint which means it will never stop at the setpoint, which is what you want.

With micropreocessor control you can measure the water temperature at the top and bottom of the engine and adjust the fan speed and shutter opening to maintain any desired spread.

All of this is academic with the buses that were built with DD 2-stroke engines as they all had either a marginal or inadequate cooling system when they were built. I doubt if any bus operator ever asked the factory to  increase the water temperature returning to the engine.

Marc: Engine designers make an educated guess at how hot you can run an engine without doing major damge. They then recommend  that the engine be operated somewhat below that temperature. That does not change the fact that you have exceeded the capacity of the cooling system when you can no longer maintain the setpoint temperature. Running it hotter than that just gets you closer to the potential damage temperature.

If you read the first post by gusc, I think you will agree that he had a non functioning thermostat and I directed my reply to him since itt appeared that he didn't understand the 'basic'  operation of the cooling system.
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« Reply #14 on: July 23, 2006, 06:45:17 AM »

Marc said:  "These points are anecdotal and don't change Stan's post in any significant regard.

Stan, AFAICR, you've shown greater understanding of cooling systems as any non-pro that's appeared on the BB boards.

Talks with Bob Sheaves leads me to believe that engineers make more than educated guesses.  In the 80's they'd instrument an engine to the cost of hundreds of thousands of dollars.  Today's new designs spend much more than that.  Bob Sheaves is currently on contract with Freightliner upgrading cooling systems.  The cost for the "upgraded" cooling system for the Austrailian trucks, used to pull trailer "trains" across the Outback, is considerably higher.   Bob touched upon this activity during the "All you NEVER wanted to know about cooling systems and were afraid to ask" seminar I more or less moderated at Bus'nUSA last weekend.

AFAIK. there isn't a particular "setpoint temperature"  due to a host of variables, what a cooling system engineer seeks/uses, instead of a "setpoint temperature" is the temperature at which the cooling system reaches equilibrium.  If that stablized temp is below the max acceptable engine mfg temp ( maybe your definition of setpoint??) it's within limits.  Otherwise, they have to increase capacity.

Basic  DD S-60 (IIRC) guidelines:  Max GVW, 12% incline, 135 deg F ambient temp.
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Stan
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« Reply #15 on: July 23, 2006, 12:36:37 PM »

Marc: My definition of setpoint is the temperature marked on the thermostat. I don't think any of your experts would recommend running a DD 2-stroke at 130* even though the system was at equilibrium.
.
DD usually recommended a thermostat in the range of 180* or 185*. A fuel injected engine is a heat engine and the hotter you can run it, the more efficient it becomes. Unfortunately, there are many physical limitations to the operating temperature. Engineers select a compromise to give good fuel economy with long engine life. If you are interested in running engines hot, do some research on ebullition cooling which was the soup de jour about fifty years ago for stationary engines.

Thermostats were installed to maintain the engine within a very narrow temperature range. Once you exced the thermostat rating, you no longer have control of the temperature. In an engine with varying load (any motor vehicle) the temperature will be all over the place and never reach equilibrium.
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boogiethecat
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« Reply #16 on: July 23, 2006, 02:10:53 PM »

Bicker bicker bicker you guys... sheesh!!

Here's how the stupid things work, it's really simple.

Thermostats control the engine temperature by moderating water flow.  The system is only "in control" when the thermostat is somewhere between fully closed and fully opened... outside of those conditions it is no longer in control, and the engine may run too hot or too cold. 
  In REALLY cold weather, the amount of cooling a radiator can do is such that even with the thermostat closed, there is still more cooling going on in the radiator than heat generated by the engine and thus the engine can never get up to temperature.  Enter shutters, which throttle down the radiator's airflow, making that part of the system less efficient so that the engine can now heat up enough to get the thermostat back into the equation. To make their control simple, they are simply set up to stay shut until the engine reaches a temperature slightly below the temperature at which the thermostat begins to open. Then they open up and let the thermostat do it's job.
  On the other extreme, shutters and thermostat fully opened on a hot day, if the engine gets hotter than the thermostat is able to control, you need a more efficient cooling system, more airflow, bigger radiator or, oh my god, misters.

Marc- I'd love to see less deferring everything about cooling systems to what Bob Sheaves says/said/might say.  He may be great, he may know more than anyone regarding cooling systems, BUT consider maybe that's for him to tell us personally, and I don't see him piping up here, just a lot of reference from you about him.  I don't particularly like to keep hearing "but Joe said".... unless Joe says it himself....
And about engineers making more than educated guesses, I disagree.  I have found that, like many professions, actual degreed engineers are quite often some of the worst thinkers out there.  Bob may not come under that category, I don't know him... but In my 35 years of electromechanical design work I've found that the best thinkers are 100% the non-degreed guys, and the degreed engineers make a LOT of stupid mistakes that get all the way to production.  Recalls anyone? All brought to you by your friendly detroit designers.... (Oh.. case in point, if Freightliner's engineers had done everything "perfect" in the first place and not taken any "educated guesses"... why are they in need of hiring Bob Sheaves to do "upgrades" for them ?? Perhaps they're in need of some band-aids for inadaquate original "engineering"?   Hmmmmm, guess there's a BIG difference between all those test stands with millions of dollars worth of bells n whistles, and the real world...  Smiley  )

Bottom line,  back to the original post, Gus, you may still have some problems.  As Stan said, the shutters are not supposed to have anything directly to do with the actual engine temperature control... they are a secondary system that helps the thermostat do it's job when other parts of the system get so cold that the thermostat is no longer in control, because it's totally shut and can't get any "shut-er". (pun intended)
« Last Edit: July 23, 2006, 02:37:28 PM by boogiethecat » Logged

1962 Crown
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« Reply #17 on: July 23, 2006, 09:28:31 PM »

Cooling systems are not sentient entities and therefore cannot be found to be stupid.

I dont' consider the exchange between Stan and myself to be bickering, more a search for common terminology. 

Thermostats do not control engine temperature, they only affect (you used the term "moderate") coolant flow in response to temperature.  The system as a whole, in conjunction with the operator "controls" the engine temperature.

You can be outside the temp range of the thermostat and achieve a stablized temperature.  The engine is only too hot when it exceeds the Mfg's maximum coolant temp.  For example 235 deg for a (some) S-60


As to your "On the other extreme"  you don't need a more efficient cooling system unless aeration is present, a condition you didn't specify.  What you actually need is a system with greater capacity.

Show me from the Bosch Design Guide, a common reference, where my quotes of Bob Sheaves are incorrect.  That was the reference used to prepare for the seminar.  Bob used to participate in the BB's but he tired of dealing with thoughtless criticism.  People didn't spend the time to consider what he said and spoke "from the hip" so to speak.

Freightliner's engineers probably did everything perfect,  except it was perfect for CONUS conditions, not Austrailia.  GVWR in excess of 280K pounds and ambient temps 10 deg higher than CONUS makes need for a much different (and larger) cooling system than the CONUS.  I raised these points earlier and you chose to "speak from the hip".   

Finally, your criticism of "degreed" engineers, states a minority but infers that the majority are so "afflicted".  I  agree that such individuals exist, but mayhaps you speak too generally. You should also consider the restraints placed on the engineer by the adminstration above him.  You speak from unstable ground unless you can establish that the engineer was given full latitude and support to complete his design.
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boogiethecat
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« Reply #18 on: July 24, 2006, 01:37:18 AM »

Oh Marc... get real and come to the real world dude.  You just love to argue don't you... about technical stuff, about politics, about almost everything.  I can see why others won't engage you.  From now on, me neither...and please remove me from your political mailing list....
Gary
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1962 Crown
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« Reply #19 on: July 24, 2006, 03:31:49 AM »

Gary,  From Wikipedia.  Searched on: "ad hominem argument"

Replying to an argument or assertion by attacking the person presenting the argument or assertion, rather than the argument itself  is (usually) a logical fallacy.

Instead of responding to the points I raised by citing their inaccuracy or pointing out the logic lapses (holes) in the points I raised, you attack the author (me) or his resource (Sheaves).

There are plenty of posts in the archives where I've apologized (even once to you, IIRC!)  when I had the facts wrong, misunderstood the issue, etc.

What's incorrect about the following point, seeking to clarify the use and meaning of the term efficient?

Closing shutters doesn't make the cooling system less efficient.  It reduces the amount of the air available to  carry away heat.   Efficiency deals with a qualitative factor when the shutters are a quantitative factor.  (Apples vs. Oranges time)

I asked you to supply facts in support of your position/argument and in response you urge me to "get real and come to the real world dude"

What's more "real world" than the facts?

Yes, I'm persistent, but only in response to either a persistant "ignorance" on how cooling systems work, or a persistant inability for me to explain basic fundamental aspects of cooling systems.

I'd wonder that you'd argue against the the theory of relativity by denying the point unless Einstein appeared in person and defended his theory.

I'm not running around like some huckster like Walker,  talking things up to gain some  personal advantage, or sell some product.  I strive for truth and accuracy.  I don't chortle and denigrate when I've made my point.  (No naner, naner, from me!)

If you really want to "make your point"  don't run and hide, tell me to "get real" or "take me off your list"  Tell me where I'm wrong and/or how I could say it better.

Isn't that what the BBs are for?




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Dallas
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« Reply #20 on: July 24, 2006, 04:30:55 AM »

OK guys,
This is as far as this needs to go.

This kind of arguing is not what the New MAK board is about and is not conducive to advancing the learning process and will not be tolerated.

If you have an opinion, that's good, but to try to force opinions on someone else is not the way to go about it.

I'm sure that Nick, Richard, Jack or myself do not want to be forced to take action here so lets try to keep it civil.

This is the first and only warning.

Thanks,
Dallas
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DrivingMissLazy
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« Reply #21 on: July 24, 2006, 04:52:24 AM »

Thanks Dallas, you just beat me to it. Course my plan was to delete the whold thing, but you did it better. Good (some) information saved for posterity.
Richard

OK guys,
This is as far as this needs to go.

This kind of arguing is not what the New MAK board is about and is not conducive to advancing the learning process and will not be tolerated.

If you have an opinion, that's good, but to try to force opinions on someone else is not the way to go about it.

I'm sure that Nick, Richard, Jack or myself do not want to be forced to take action here so lets try to keep it civil.

This is the first and only warning.

Thanks,
Dallas
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Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body. But rather to skid in sideways, chocolate in one hand, a good Reisling in the other, body thoroughly used up, totally worn out and screaming:  WOO HOO, what a ride
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« Reply #22 on: July 24, 2006, 08:10:02 AM »

Thanks Dallas and Richard.  Totally agreed.
Cheers
Gary
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gus
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« Reply #23 on: July 25, 2006, 07:00:00 PM »

Well, I never expected to have my original post end up like this.

There is only one person I know that writes like Burgermeister and I thought he was gone!!

Oh well, one can hope.

Anyway, the bottom line is that my 4104 is maintaining the proper temps, at least for now, and I am happy. I don't really care what the theory for cooling is?
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PD4107-152
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