The thread running right now about the MCI 7 Combi with electric radiator fans got me thinking. Has anyone attempted to use the electric motor from either the condenser bay or the heater system to run the radiator squirrel cages? There may be some very simple reason not to, such as proper rpm etc. All the necessary pieces are there in the heating system, relays, wiring etc. Maybe just run wiring from the alternator direct to the motor, with the relay to turn it on? I think that's kind of how the heater system works. Any thoughts?
There was a big debate a while ago about whether one could cool with only electric fans. Someone was trying it and, I am told, it did not work out. However, there is a guy posting on BNO that says that is just what he is doing. It's not at the beginning but further down.
http://www.busnut.com/bbs/messages/11/20738.html?1204862467
Anything can be done...just a matter of how much time and money you want to throw at it.
I think the guy in the post referenced above decision was skewed by the fact he was repowering with a cummins.
probably much easier to engineer his elec setup than try to get pully's and gearboxes figured out
Simple- you just can't get the air flow with an electric motor compared to direct drive electric. Now with Hydraulic-that's another story. You could run it off the power steering pump with a priority valve that gives the power steering first crack at the pressure with the fans being secondary. Electric was tried on big rig trucks that have great frontal ram action into the radiator, and it just plainly didn't work on those long grades in summer time. Good Luck, TomC
There is lots of engineering data and empirical data on how much horsepower is required to move sufficient air to cool an engine. Detroit two strokes are one of the hardest engines to cool, consequently they need the greatest amount of air flow.
You can increase the surface area of the radiator or you can add more rows of tubes, but in either case you increase the horsepower required to move sufficient air.
Anything is possible even if not practical, and there seems to be little reason to redesign a system just to eliminate a belt.
It can be done, because I have already done it. When I bought my bus in 1998, the previous owner had removed the belt drive for the fans and replaced it with a 24v motor (which wasn't working well). During my investigation, I removed the bad motor and cages and installed 2 pairs of electric fans, 2 push and 2 pull, and connected them to a thermostat. The fans operate fine, cool the engine well, but here in Florida I needed more water flow and decided to install an aluminum radiator in the condenser bay behind the drivers side front wheel. This made an even more dramatic impact on the temperature and it also had an electric fan. I have since decided to get rid of the original 'suitcase' radiators in the back and replace them with similar aluminum radiators because they are much more efficient.
I have found that the problem is not using a particular type of fan (electric, hyd, belt) but the efficiency of the radiators themselves. The originals in mine are 8 row, staggered, smooth tube, straight fin and I believe 1/4" tubes. The additional radiator installed is 2 row, 1" tubes and is all aluminum. Part of the problem is trying to get the airflow all the way through the core. By using the push and pull fans, I have kind of gone around the problem of improving the air flow, but these 'antique design' radiators are essentially hot water bottles that have poor air flow. The design is much older than most of our buses and is inefficient for cooling. When I check the airflow and temperature around the new radiator core, the center is much, much cooler than around the perimeter of the fan. The older radiators (stock) are hot all over and do not have a cooler area to be found.
When I install the new aluminum radiators, I will be installing shrouds to improve efficiency and they will be a 'pull' type fan only. By the way, the current setup has been working fine and not a single temperature problem was encountered during my recent 6k mile trip that included going into Mexico. I hope this helps.
Ben MC7: As so many people have said, anything is possible if you spend enough time and money on it. I am intrigued by this statement
QuoteThe fans operate fine, cool the engine well, but here in Florida I needed more water flow and decided to install an aluminum radiator
Why would you add more coolant and an additional radiator to a system that was working well? If you needed more cooling in Florida, try one of the long grades in the SW mountains on a hot day!
One small error in my description of the system--
I removed the heater core that is installed in the forward baggage compartment. With the lack of water flow (and quantity of water) going to the front of the bus, it made the system much smaller. By installing the additional radiator in front I regained the system capacity that was limited without the heater core that was originally removed.
Yup. Stan has the idea. Any bus can function with electric fans... on the flats going slowly... but get over to this part of the country and try, for example the Baker grade when it's 115 outside, or the grapevine under similar circumstances, or even the final grade going west on I-8 in the middle of summer, and you'll WISH you had belt or hydraulic-driven fans again.
For example, my Crown runs at 180 day and night at 70mph fully loaded with a 6000 pound trailer, with the fan spinning at 20% of it's normal speed (I have a Horton eddy-current 2 speed clutch on it). Probably very equivalent to the biggest set of electric fans I could ever muster. But as soon as I hit those grades, the fan goes fully on and I'm also thankful that I added 3 inches of thickness, the new style to boot, of core to my radiator, or I'd never make it. Even then I'm pushing 205 degrees which is the limit for my old Cummins 220. It's only those times when electric won't cut it.
This has been thrashed over and over during the years. Everyone from the 2dogs debacle to Tim S. has said they could, actually done it, or whatever, and thus far no-one has been happy with the results. And as I recall, Tim even did it "right", with a gigantic high horsepower DC motor and the proper controls, then given it up 'cause it just didn't work. Bottom line, you just can't easily get that 20-30 HP from electric fans, and that's absolutely needed when the goin' gets tough....
Wow! I had no IDEA of how much this has been discussed. I found the BNO post dealing with Two Dogs. What a mess. I think I'll drop the idea and stick with what works. I know there is merit to going to aluminum radiators when possible/practical. I did the same on a 63 Ford Galaxie. Makes a big difference. I don't know if I'll ever get west, but I don't want to be stuck worrying about not being able to!
A side note,
As I read through the Two Dogs post on BNO, I was really taken aback by just how unpleasant the postings were. I am glad that I have never seen such inappropriate behavior here. I also have to say that things have not been as bad as that since I joined BNO as well. Different opinions are one thing, but there is no excuse for being hurtful.
This is not exactly on the topic of electric fans but it is related to this post.
According to this post & the others I can find, belt driven is the only way to go when it gets hot on long grades. It also appears that the belt driven system takes 25 to 40 HP depending on whose figures you want to rely on.
Assuming the above is so, it would be nice to reclaim that HP, when it is not needed for cooling, to increase fuel mileage.
To that end, is there anyway to easily adapt an air operated fan clutch to shut off the fan and gear box when not needed on an MCI? Has anyone done that?
TOM
Granted aluminum radiators do work well-Freightliner, Sterling, Western Star have all switched to them as the standard radiator. But look at Western Star (the heaviest duty truck we make), when the radiator needs to get big (1850 sq in) we switch back to the good old copper/brass design. Although aluminum has excellent heat exchanging qualities, it also has excellent calcium collecting qualities since it is a more porous metal than copper. Hence after a few years, the calcium collects and blocks the tubes, and since aluminum is so soft and the tanks are just clamped on plastic tanks, they are typically not repairable-just replace them. As compared to the copper/brass radiators that have metal bolted end tanks that easily facilitate rodding out the core when needed. When I had my copper/brass radiator core changed from a 5 row straight fin to a 6 row serpentine fin core, the radiator guys said the original core was clean and still in good shape-and I've owned the bus for 15 years alone! During that 15 years if you had a aluminum radiator, you'd probably already have replaced the radiator once with getting close to replacing it again. Good Luck, TomC
Ben: The heater core has nothing to do with the fans cooling the engine unless you are running the heater fans to remove heat from the core. Increasing the volume of the system only delays the point where the fans cannot keep up.
Just to add to Boogie's comment about the grade between El Centro and San Diego. I have driven that road with three different cars and not one of them would pull the grade to the top in the highest gear without overheating.
Tom: I think the original MCI design does more or less what you want. With a proper operating shutter and damper system, you unload the squirrel cage fans when cooling is not needed.
The MC-5 cooling system is as I've been told, marginal at best. While I have my 8V71 out to replace the clutch I am considering adding a third radiator with electric fan where the AC compressor used to be. Anyone have experience with this approach? It looks like it would be easy to add the third radiator in series with the passenger side radiator.
A side note,
As I read through the Two Dogs post on BNO, I was really taken aback by just how unpleasant the postings were. I am glad that I have never seen such inappropriate behavior here. I also have to say that things have not been as bad as that since I joined BNO as well. Different opinions are one thing, but there is no excuse for being hurtful.
[/quote]
Tenor, you should have been here before Nick,Phil,Dallas, and Richard and the new board I forgot Jack sorry
Quote from: Tenor on March 07, 2008, 07:36:24 AM
Wow! I had no IDEA of how much this has been discussed. I found the BNO post dealing with Two Dogs. What a mess. I think I'll drop the idea and stick with what works. I know there is merit to going to aluminum radiators when possible/practical. I did the same on a 63 Ford Galaxie. Makes a big difference. I don't know if I'll ever get west, but I don't want to be stuck worrying about not being able to!
A side note,
As I read through the Two Dogs post on BNO, I was really taken aback by just how unpleasant the postings were. I am glad that I have never seen such inappropriate behavior here. I also have to say that things have not been as bad as that since I joined BNO as well. Different opinions are one thing, but there is no excuse for being hurtful.
Tenor, That's the smartest answer I have seen in a long time. If you think about it how many of the big boys I.E. MCI, PREVOST. use electric fans to cool their power plants. You are wise beyond your years to read and listen to the addvice you find on this board. You my friend get an ATTABOY today, way to go.
WVaNative
Can someone tell me the difference in a hydraulic fan motor and electric controlled one with the same rpms and power as most are using the hydraulic fan motor now and isn't the fan on the new D4505 MCI a three speed electric fan I didn't notice any belts but I did see the 3 speed fan switch in the drivers area
A 40 hydraulic motor is much, much smaller than a 40 hp electric motor.
It is all about heat rejection. The bigger/ more efficient the radiator, the less air flow you need.
A centrifugal fan uses little HP to make pressure, it is moving the air that requires the HP. So closing off the inlet to the radiators will drastically reduce the power requirements to the fan.
If the electric fan supplier can't provide a fan curve, the fan probably isn't suitable for bus radiator cooling.
As for why manufacturers use hyd drive over belted - My guess is it is easier to design & fine tune. Not to mention more flexibility in radiator placement.
If I were to change from original on my Scenicruiser, my preference would be a hydraulic fan mounted to the swing out radiator. This would make engine access easier & solve the issue of expensive repairs to the fan drive gearbox.
Stan,
Unfortunately, the PO removed most of the shutter system and, even if he didn't, it still take HP to turn the gearbox..... not to mention the normal wear on the components. That is why I was asking about a clutch system.
Kyle and anyone else with a 4501: The miter box that has the fan attached can be a nightmare. It uses tapered roller bearings (which aren't the best choice for end thrust) and if they fail you have to machine the casting for a different bearing and seal. The bevel gears are 1:1 which means they are worn in in one spot. If you have to remove the shafts ensure that you mark the gear teeth before removing the shaft. Setting up the gears with shims is like setting up a crown and pinion. You torque it all up, blue the teeth, turn it one turn and then take it apart to change shims and do it all again. If you haven't marked the teeth before you take it part, you have several days of work trying to get it back into the original mesh before it will set up properly.
You are fortunate in having parts buses. When I looked for a gear box, I knew where there were several scrap 4501s and they were all missing the fan box.
oldmansax: If you use a conventional fan clutch, you will still have the belt turning the hub (the clutch goes at the fan, not on the crankshaft).. The additional HP required to turn the gearbox without a fan load will be small. You would be saving most of the HP that is wasted when cooling is not needed. However, it is like the electric fan discussion. If you spend enough time and money, anything is possible.
Oldmansax, I don't know the particulars of how much space you have in your fan area, but I can tell you what I did with my Crown.
Horton makes an eddy-current 2 speed fan clutch for skid-steer tractors. It's not too big and costs around $600 depending where you dig it up. It's all set up for serpentine V groove belts, so it wouldn't work as-is on my Crown... but that never stopped me...
I bought one, machined a V-belt pulley for it out of a 9" steel disc (That was one ugly lathe job), pressed it on where I'd machined off the serpentine belt grooves, and there I had it, a nifty doodah for my Crown that lets the fan lazily idle along most of the time, until my engine hits 185, the sensor gives it 12 volts: full on it comes. It works amazingly well.
I'm guessing 1-2 Hp most of the time and then when my big monster fan needs it, full-bore!!
Here's the part numbers and where to get em...
For Case tractors, It's called an "ECI" and is availiable as an option on skid steers...
Case P/N is: 336 635A1 $560.77 as of a few years ago
"Fan mount with Clutch" (it is NOT an Agricultural tractor part, so make sure you have the Skid-steer guys on the phone)
Horton's part number is 996500
HORTON engineering (fan drives):
1-800-621-1320 cust support
A 190 degrees mechanical snap action switch is part number 993617
Maybe these days they make easier ones to modify or directly use. When I got mine, Horton was just getting into it all and they were pretty scarce.
The nice thing about these as compared to air clutches, is that that these use eddy currents (made by permanent magnets) to drag the fan along slowly when the clutch is off, and then when the clutch is on, full bore. The two speeds that the thing creates is exactly perfect for buses... at least mine.... Air clutch systems are pretty much on or off, and don't have the nifty two speed feature.
Someone may have already described his post, but Mark Renner appears to have solved the electric radiator/motor thing. He's got some new pix of his setup over on the BNO board. Renner HAS engineering skills! He's got a to-die-for Eagle too.
While I wouldn't try this due to my total lack of engineering skills, an electric motor would not have to be a fraction of an ICE exchange.
Large DC motors (any size motor in any voltage) is readily available.
I have a 30 HP Advanced DC brush motor in an electric car that would rip the fans apart in a bus. It is far more powerful than the 180 HP ICE engine that it replaced. At the least, it has huge torque and power available.
I'd guess a pair of 2 HP DC motors would supply enough airflow for a properly engineered cooling system.
My thoughts would be that if automotive applications work with electric fans, a bus engine could be cooled with an electric fan, or fans, if someone wants to go to the trouble. I see the engineering as the hangup. Even some GM Suburbans had only electric fans cooling 454 engines with automatics and AC. It worked fine.
Placing one huge radiator with two fans in the rear of a MCI similar to a D model should make cooling easier. There would be a natural flow thru the radiators at highway speeds...unlike MC5 thru C model bus radiators.
What I would fear with these sorts of mods is a failure on the road. Where do you get parts?
One thing's for sure...if the MCI rad fans really draw up to 40 HP...that would be worth some effort to recover.
When I replaced the EEPROM in my DDEC and found a little over 300 HP (from 270), it made a world of difference...40 more HP would be great!
Now who's gonna try it in an MC with side rads??
JR
you'll note that mark is not running a detriot....I do not know if his new poerpalnt runs cooler than a DD.
now bringing up cars is apples vs oranges.....NO ram air cooling on a bus radiator..pretty much anything through it must be sucked through, also keeping in mind it takes a bit off effort to suck air in that is flowing past at 60+ mph.
not to say it can't be done, just takes some effort and engineering and cost.
Alot more folks out there that have tried and failed than succeeded.
I made a set up that if I need extra cooling on my mc8 with a 8v92, I can use the big bus interior heating radiator and exit the heat to the out side of the bus instead of the inside.
I beleive that the most efficent and economical way to increase cooling capacity on MCI is to add aux air to oil trans cooler. Mine is as big (my cooler) as the side access door in the pic (18" x 24" x 3") with 24 volt elct fan.
Its dual controlled, I have a toggle switch on the dash and it also has a sensor thats turns on the fan when the engine temp gets to 205.
This cooler was made for Allison and the fan is a Hayden. I paid $125 including shipping for the cooler and $65 Inc ship for the fan, both via ebay. Both were new.
The fan never runs auto, sometimes I just turn it on to watch the water temp drop whie driving.
Of course, I remove heat from the trans fluid in order to remove heat from the engine coolant.
I also turn off the gate valves that supply heated coolant to the front of the bus in the summer time, so the originall bus beater core and lines capacity arent any effect in the cooling issue.
I am running 8V71TA (377 hp) with HT740D with all stock cooling components that are set up and maitained properly. ( all is clean with good gaskets and such)
The biggest "hill" that I've been over is MontEagle in Tennessee- I flipped on the trans fan and cruised up at 45 mph. No cooling issues!
About $200 plus two hoses for the trans cooler setup. EZ install also- HTH Chuck
I hope you can believe me when I say that electric fan cooling just doesn't work. Even the huge 300 amp @ 14vdc Delco alternator (as huge as it is) only creates 5.6hp of electricity. For proper cooling you need at least 20hp. This is why hydraulic is used. Both the pump, motor and hydraulic lines are rather large. Believe me if electric was possible, the OEM's would use it since electric is a whole lot simpler than hydraulic. Instead of trying to reinvent the wheel, stick to what is proven-especially since our lovely 2 stroke Detroits are thee hardest engines to keep cool. Good Luck, TomC
Quote from: boogiethecat on March 07, 2008, 06:43:14 PM
Oldmansax, I don't know the particulars of how much space you have in your fan area, but I can tell you what I did with my Crown.
Here's the part numbers and where to get em...
For Case tractors, It's called an "ECI" and is availiable as an option on skid steers...
Case P/N is: 336 635A1 $560.77 as of a few years ago
"Fan mount with Clutch" (it is NOT an Agricultural tractor part, so make sure you have the Skid-steer guys on the phone)
Horton's part number is 996500
HORTON engineering (fan drives):
1-800-621-1320 cust support
Thanks Boogie!
I have a MCI MC7 with the usual belt/gearbox setup. I was thinking of a clutch that would bolt on to the front of the crank shaft replacing the existing V belt pulley that now drives the fan gearbox. This arrangement would eliminate the belt, gear box, and fans when the clutch was not engaged.
It appears that one of my major problems in designing and installing this system so far is I am both LAZY & CHEAP! ;D ;D ;D
I am working to overcome those obstacles but it is an uphill battle!
Thanks for the info, though. I will take some measurements (that is easy to do & low cost) and see if I have room for your arrangement.
TOM
Oldmansax,
Keep in mind there is not much room between the engine and the bumper support/cradle support. It may be easier to put this on the gearbox. Keep us posted!
Quote from: TomC on March 08, 2008, 05:12:18 AM
I hope you can believe me when I say that electric fan cooling just doesn't work. Even the huge 300 amp @ 14vdc Delco alternator (as huge as it is) only creates 5.6hp of electricity. For proper cooling you need at least 20hp. This is why hydraulic is used. Both the pump, motor and hydraulic lines are rather large. Believe me if electric was possible, the OEM's would use it since electric is a whole lot simpler than hydraulic. Instead of trying to reinvent the wheel, stick to what is proven-especially since our lovely 2 stroke Detroits are thee hardest engines to keep cool. Good Luck, TomC
TomC you are wrong about the electric cooling 90% of your buses made in China and Spain have electric cooling only.In the US the price of fuel has never been a concern till now and you will be seeing more a electric fans here in the future to save on fuel even the hydraulic powered fan create a large hp drain on the engine have a good day
In reading the almost parrelell threads on two boards I have come to the conclusion that with the brain trust available a viable solution should be able to be obtained. Leaving one to their own devices to do the design and implement a solution is asking for the mixed results we hear about. I will grant you that since I am running a 4 stroke my heating issues are not as great as those of you with DD's. So I am going to proffer some hypothysizes and those of you with the knowledge and desire take your best shot and refute the hypothesis. From this I believe move from the apples and oranges situation we keep getting stuck on.
Hypothis 1: HP is the resultant efficiency we are trying to gain not the input of the equations.
reason: If it was nothing more than HP waste then there wouldn't be any difference between my
Class C 460 running 18K # @ 4 MPG and MCI L10 28K # @ 9 MPG.
Hypothis 2: When one is looking at the dissipation of heat in the form of BTU/H then all of the system needs to be
looked at not just the engine.
reason: The transmission is a tremendous heat generator. I can tell you from personal experience that being
on the transmission test bench having a hose burst and being burned was not fun. That was only a
100 hp bench. I believe Chucks transmission cooler set up needs to be included in an overall design.
Hypothis 3: Squirrel cage fans are more efficient than blade fans in moving air.
reason: In trying to redesign my coach heating system I was amazed how hard it was to find like SFCM
with the same amp draw.
Hypothis 4: Electric motors per hp turning an item are more efficient than the same mechanical (engine) hp.
reason: It is one of the major reasons locomotives use diesel over electric.
Well there you have what I consider a start. Please if you can provide formulas and the such that would be great.
This soft science of my hypotheses won't cut it but I need more of which you with the capabilities can supply.
I really think that if I can show a positive ROI in a 2 or 3 year period I would be trying a conversion.
Thanks
Skip
PS I have tuff skin on this so flaming me won't bother me a bit :)
Skipn- your hypothesis sound good on paper, but there are still some myths I have to discuss. Hypothesis 4 is not correct. Thee only reason that trains use Diesel/electric is that you don't need a transmission or clutch/torque converter to get the load moving. An electric motor has the neat built in feature that it puts out maximum torque at zero rpm and maximum horsepower at full rpm-just perfect for getting a heavy load moving. Early Diesels tried the same setup as steam trains, first starting on compressed air then at about 15mph could ignite the engine-but obviously that didn't work. Running Diesel/electric is inefficient. First you have the engine driving the generator for about 96% transmission of power. Then the electricity running through switching and through the electric motors makes for about another 95% efficiency-so you loose about 10% power or fuel burn with a Diesel/electric. The most fuel efficient is direct drive anything-case in point is the big container ships using a single 2 stroke engine directly (no gear reduction) driving the propeller. Those big container ships both have the most fuel efficient Diesels made and can move the most tonnage with the least amount of fuel possible.
Makemineatwostroke- in regards to the electric fan buses in China and Spain-I think you'll find that they don't run two stroke engines. If I put a Series 50 in my bus, I would also feel confident in using electric fans to cool the engine. But with the combination of our 2 stroke engines, limited radiator size, no frontal air ram like a truck, the most prudent is to stick with the tried and true that is already on the bus. I have a big 30" 8 blade fan on mine that is direct drive that I know is sucking big time air and horsepower, built for reliability, I'm leaving it be. Good Luck, TomC
Tom,
Thank you for your point (well taken) I would like to offer that (if I remember my class days) that
from engine to wheels there can be a loss of up to 50% of HP. The current set-up on an MCI of belt
to gear box has to have some loss. The question is is it more than the 10% you stated of electricity
created and transmitted to be used. So the real question to start off whith is:
Is the power loss of a belt system to a gear box greater than 10%.
Again thanks
Skip
TomC, the biggest draw back cooling a V series two stroke is the design.You have a water pump on the left side pulling water from the oil and transmission cooler first then you have the crossover pipe pushing 200 + degree water to the right side this system hasn't worked for Cat,Cummins or anyone else with out large radiators and fans.The great part about removing heat from a 4 stroke you can move the heat with turbo boost won't happen on a two stroke in fact it will make it worse water only for cooling a two stroke Henry Ford had it right on his flat head engines a water pump for each side
The MCI guys have a problem with cooling because MCI would not give up on their idea about the radiators staying cleaner mounted up high but the problem with this was you had a water pump not design to pump water with a 4 ft head on it and was already at a high temperature from the engine.Water doesn't like to go up hill easy and we tried to tell this to MCI for years but when you have the best selling bus why change also they lose the air movement after certain speeds less air for the fan system to pull into the radiators and I don't know if a electric fan would work on these or not. A simple test for these guys is use a 6 ft long piece of yarn tied to the bus and watch the movement on it at different speeds Buses that have a low and side mounted radiator like yours and other bus are far easier to cool than the high mount systems some manufactures use have a good day
Is there any value to adding an air scoop to the sides of an MCI?
scoops are a benefit,
Other than the exposed are of the low side mount radiator, I do not see any difference between those of GM two storkes and the MCI's high mounts. why would it be any easier for radiators mounted lower to sucjk air vs those that are high mounted?
So why doesn't someone just take the RPM reading of one of your squirrel cage fans when your engine is at peak RPM, and then remove the drive to the fan and put a big DC motor on it, run it up and measure the voltage/current (ie horsepower) it takes to duplicate that measured RPM. In a nutshell all the arguements would become clear as to whether it will or will not work... Maybe we can all place bets... :)
Quote from: Stan on March 07, 2008, 05:39:03 PM
You are fortunate in having parts buses. When I looked for a gear box, I knew where there were several scrap 4501s and they were all missing the fan box.
They ain't parts buses, they are still viable buses - except for 011 - If I start removing essential parts, then they will become scrap & there are too few of 'em left as it is.
I know all about the gear box, even talked to Ohio Gear about new gears & shafts. Yep, still available . . . Just the low sales volume means the overhead is placed on fewer parts which translates to higher price. :'(
If one is going to re-design the cooling system, it occurs to me that there are many things one needs to know, some that come to mind ;
- how much heat rejection is required
- radiator efficiency
- coolant flow rate
- The above are used to determine how much air flow is needed thru the radiator.
I'm sure there are lots more things that will influence the results . . . . . .
Quote from: boogiethecat on March 08, 2008, 12:32:55 PM
So why doesn't someone just take the RPM reading of one of your squirrel cage fans when your engine is at peak RPM, and then remove the drive to the fan and put a big DC motor on it, run it up and measure the voltage/current (ie horsepower) it takes to duplicate that measured RPM. In a nutshell all the arguements would become clear as to whether it will or will not work... Maybe we can all place bets... :)
Could the max RPM of the MCI squirrel cage blowers be deduced from the gear ratio of the gearbox and pully drive?
If the box is 1-1, a tape on the pulleys would give that ratio. I'll bet the drum RPM is about the same as the engine RPM.
The CFM of the blowers could be found in an HVAC manual...I'll bet Nick or Christy could offer an excellent idea of what the CFM of a similar sized squirrel cage blower might move. Multiply times two and we have an idea of the CFM requirements of a fan. I'd bet there's a table of HP requirements available for such applications? Nick?
This is an interesting idea, however, I tend to agree with Tom. It's more trouble than it's worth to fab up an electric system. And the custom radiator is going to be made of unobtainium. Probably manufacturing cost, and not efficiency, is why MCI used the squirrel cage blowers and split radiators for so long. They never were ideal cooling devices.
And I'll add a Hypothesis 5: If you use a bladed fan, sucking is far more efficient than 'blowing' air thru a radiator. A blade fan in a properly designed shroud is quite efficient. The shroud makes all the difference.
Don't MCI D models have the fans on the rear of the radiator? Seems as though the D model with the radiator centered up in the back would have a natural airflow thru the radiators at highway speeds. The rear of the upper cap should create a massive low pressure area, and should pull a good bit of air thru the side intakes while driving. This natural effect would not be available on lower single side mounted radiators. That's a question...
One other point to keep in mind is that the engine compartment is kept cool by the radiator exhaust flowing over the engine...the lost flow would have to be made up by ducting or another blower of some sort.
An oversized radiator would also add to the ability to cool with minimal airflow.
As would separating out the transmission, and perhaps engine oil cooling. The engine oil cooler should be shunted back to the engine coolant in cold weather.
An electric motor large enough to spin a radiator fan may not be more than a couple HP.
Our MCIs have 275-300 amps at 24V, so there is a good bit of headroom..much more if the OTR AC is not used.
Anyone with the fab skills to convert to an electric cooling system could easily repower with a 4 stroke to make the conversion complete. There are all sorts of 4 stroke donors on the market now. Cummins and Cats. Cummins is a better choice. Complete running tractors for $2K isn't unusual. They may need a little freshening up, but..that's doable. A Cummins will offer the best fuel mileage.
Even an occasional S60 is available in a wreck..but they are complicated to install in MC7-9s.
JR
I've seen a picture of the new MCI's-they have huge radiators with huge multi blade (12 blade I think) fans that are belt driven. One for the air to air and the other for the radiator-both with individual hub clutches.
It's sort of a curious thing that people think that using an electric motor is going to save them fuel. If you have a 10hp draw fan that has a thermostatically powered switch so that it only runs when necessary, the belt driven will be the most efficient, an electric next and hydraulic the least efficient. No matter what, if you have a 10hp fan, you're going to use the same amount of fuel whether the power comes off a belt drive, through the alternator and batteries or through a hydraulic pump (actually a bit more with hydraulic). Personally-big trucks all have direct belt drive fans with thermostatically controlled clutch hub. What could be more efficient? Good Luck, TomC
Interesting discussion.
I was poking around in my 4106's engine compartment today, after reading this and the BNO thread last night, and got to looking and thinking about how GMC handled this "lost HP vs cooling" issue.
Now remember, on a GMC, there are NO belts of any kind - everything is directly driven off the powerplant, in some way.
In the case of my '06, GM used a torus drive for the cooling fan - conceptually a hydraulic version of Gary/Boogie's Horton edy-current electric fan clutch. When cool, the fan just sort of idles along, almost free-wheeling. However, as the temps rise, more oil is fed into the torus, until it literally becomes locked up like a torque converter and you've got direct drive. Pretty simple and effective - and only draws additional HP from the engine when it's needed.
I know that back when I was working in the charter business, I NEVER had a GMC overheat on me, even on the infamous Baker Grade on I-15 or climbing the Grapevine on I-5. Of course, these were stock, 275 hp motors (N60s/std timing), not the high-HP engines stuffed in many a coach's tail nowadays. NEVER had an MCI overheat on me either - but you had to watch the temp gauge a LOT more closely than with the GMs. Of course, that's part of the secret - driving technique. Maybe the biggest part. . .
Oh, one other point: GM also included a full-width mud-flap across the rear of the coach directly behind the rear axle. It's purpose was two-fold: Act as a mud-flap, and create a low-pressure area underneath the powertrain, to help exhaust the hot air being blown in by the cooling fan while at speed - basically anything over 40 mph. Amazing to me how many are missing, or a second one has been added hanging from the back bumper to keep stuff off the toad, but defeating the purpose of the factory flap.
I'm sort of like TomC on this - for the average busnut with a STOCK DD two-stroke powertrain, it's awfully hard to second-guess the factory!
FWIW & HTH. . .
;)
Often wondered why on the bus V blocks they convert the engine to a single out for the engine water return. On my first truck with the 8V-92TA, it had an outlet from each head with a thermostat, so it had two hoses going into the radiator. Just a comment. Good Luck, TomC
Tom, I think that the answer is that buses took less horsepower to push, which meant a lower fueling rate and less heat to reject. I can't see any reason that it should be any more complicated than that.
School buses cool just fine while in their original use, but when they go on the highway, they have problems with overheating. I've seen this in a bus with very comparable engine horsepower to a highway rig.
I just see the problem as an average fuel rate, more than anything else.
Tom Caffrey
Hi all, saw this MCI J4500 at WWWilliams, lvmci...
J4500
On my RTS with 350HP pushing hard up the mountains I installed a 6 row serpentine fined radiator, and then a radiator water spray system. My latest endeavor was using an RTS heater core that measures 3x36" with three rows, all aluminum, powerered by 3ea 12" car electric fans. It gets activated by a 180f switch and blows out the top roof screen. I can tell the difference climbing mountains.
Prevost's are using electric fans now also,there was one dead in the water in Needles that the designated alternator for the fans failed ,I bypassed the alternator and tied into the main starting system and he made it to Prevost in Ca.Before you run out buy electric fans those are not the 80w fans you buy from the local parts store they are high amps for power
I saw a new Prevost at the bus bash at Hershey, Pa. It had wall to wall fans on the radiator and three alternators.
Lots of Nova transits with entire radiator/air to air covered in these electric fans now.
Where's 2 dogs?
Maybe the OEM have redeemed him?
Happy coaching!
Buswarrior
Big difference between a transit running electric fans and an over the road bus. The only way I'd run electric is like Geoff on an auxiliary radiator. Good Luck, TomC
Quote from: TomC on September 15, 2018, 05:55:32 AM
Big difference between a transit running electric fans and an over the road bus. The only way I'd run electric is like Geoff on an auxiliary radiator. Good Luck, TomC
Those fans work and put 50 hp to work for other purposes increases fuel mileage to,plus now the $3000.00 Lining fan clutch is gone. They are neat they only come on 1 at a time as needed but they are high amp fans for power technology is here TomC even construction equipment are using electric fans,5 of those will move more CFM of air than a engine driven blade will so they say
Quote from: luvrbus on September 15, 2018, 06:37:10 AM
Those fans work and put 50 hp to work for other purposes increases fuel mileage to,plus now the $3000.00 Lining fan clutch is gone. They are neat they only come on 1 at a time as needed but they are high amp fans for power technology is here TomC even construction equipment are using electric fans,5 of those will move more CFM of air than a engine driven blade will so they say
Yup. Two Dogs is probably sitting on a mountain of cash in Figi, Tahiti, laid back with island girls on his 134' yacht drinking drinks with little umbrellas. for all of his innovative designs and patents :)
As I remember he insisted electric fans on radiators would work. He was ahead of time, although he failed to install the fans after someone on the board sent him some free ones.
Quote from: Geoff on September 15, 2018, 09:28:27 AM
As I remember he insisted electric fans on radiators would work. He was ahead of time, although he failed to install the fans after someone on the board sent him some free ones.
Yea him and George went after it for awhile,I haven't heard from him in 3 or 4 years wonder if he is still around