| Author |
Message |
Ken Klunder (Novice) (209.112.145.225)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 14, 2002 - 8:52 pm: | |
We need to find a location for a generator in our MC 9. We have a wrico 8kw generator with thoughts of putting it in the front cargo bay under the driver. Any comments, thoughts or experiences on which bay or compartment would be the best location?
The Alaskan Novice
MCI MC 9
#S15327 |
Ross Carlisle (Ross) (207.88.97.243)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 14, 2002 - 9:37 pm: | |
I just went through this. I installed a Powertech Diesel in the forward baggage bay on the drivers side. I assume thats what you were thinking as well since there is no baggage bay under the driver.
I've heard of people putting them in the AC condenser bay, but every genset I looked at would not fit, even thought every manufacturer said that thier genset would fit there. Even Powertech said that thiers would fit. Fortunately, I'm bright enough to know that a 24" wide genset will not fit in a 22" wide area, so rather than arguing that point, I just planned on installing it in the forward baggage bay right from the start.
It worked out very well, and considering the bus is still a shell inside, the genset is surprisingly quiet. I'm very pleased with my choice in gensets.
Ross |
Buswarrior (Buswarrior) (64.229.210.148)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 15, 2002 - 12:57 am: | |
Hello Alaskan!
You need to think hard about putting the generator in the first bay if you are keeping parts of the stock coach heat or air. Exhaust fumes have a sneaky way of funding their way in through that plywood fan access door.
Regardless of that decision, all the little holes and seams between the generator box and the coach interior need to be sealed on every generator installation so that the exhaust doesn't get in the coach and poison you.
Be safe, breathe fresh air!
happy coaching!
buswarrior |
Jim Ashworth (Jimnh) (172.136.37.150)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 15, 2002 - 7:43 am: | |
The only genset I found would fit in the a/c condensor compartment is a 6.5K non-RV Onan diesel. The rearward end of the compartment had to come out in order to do it. With an 8K, look at installing it in one of the bays, being aware of the weight that it will put on the front axle if in the front bay. Perhaps the center or rear bay may distribute the weight better.
Jim |
Ross Carlisle (Ross) (207.88.96.230)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 15, 2002 - 9:50 am: | |
Jim...
I went with the front bay because the rear bay is where the tanks are going. I figured it would balance out. Besides, the genset is only 500lbs. I'm putting the electrical components in the forward bay, LP in the AC condenser bay and tanks in the rear bay....Leaving the center bay completely open for pass through storage.
Ross |
Peter Broadribb (Madbrit) (170.215.32.248)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 15, 2002 - 2:26 pm: | |
Ross,
that was my thought exactly. My generator is 650 lbs and I reckon that equates to only 3 adults, maybe 4 smaller ones. That is only the occupants of one row of seats.
However, I may still put it further back such as under the kitchen/bathroom area purely as a sound deadening exercise. I figured that it would be a lot quieter being under the area which has the most covered with cabinets etc.
I have a Onan Quiet unit and have yet to figure the exhaust system that is easy to split apart if I want to remove the unit on a slider, otherwise I need access to the rear of the unit as well.
Peter. |
Ross Carlisle (Ross) (207.88.97.85)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 15, 2002 - 3:17 pm: | |
Peter...
I was going to put it on a slider, but the Powertech is so easy to service without removal, I didnt do it. The exhaust goes out the floor of the bay and goes about 5 feet forward them makes a left turn to the muffler. The muffler is under the AC condenser bay. My first thought was to run the muffler back 5 feet but that would have put it right in the middle of the bus wheelbase. I figured if anything is going to be hanging slightly low, it should be close to one of the axles to avaoid high centering. Since the genset is closest to the front axle, I positioned the muffler closer to the front axle.
I basically have a removable wall dividing the forward bay. Normal service can be done easily from inside the bay. Rear access can be had by removing the divider wall...Might even install an access door in that wall. I figured if the genset needs servicing to the point that it needs to be removed, it will be serious enough that the genset will be headed back to Powertech for repair.
To place it under my kitchen area, it would have had to go in the center bay. I really wanted to keep that bay open. You may be right though...It may be a little quieter there.
I also plan on building a sound proof box that will slide over the genset and be easily removable for service.
Ross |
Henry R. Bergman, Jr. (Henryofcj) (63.164.175.132)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 15, 2002 - 3:40 pm: | |
The neat thing about basic math is that a particular piece of coach equipment of known weight (such as a gen set) can easily be calculated as to its exact effect on the weight and balance of the coach front to back and side to side.
One month ago I didn't have a clue as how to do this. I'm kinda slow. A 12 year old kid showed me how. The point here is that before a permanent location is determined, do the math to see EXACTLY how the weight is going to effect all four corners (6?) of the bus.
Estimating here is not going to work. You will need to know exactly how the coach is going to be balanced before any wrenches start getting turned. This way there are no suprises later going down the road. Thanks. |
Peter Broadribb (Madbrit) (170.215.59.13)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 15, 2002 - 4:26 pm: | |
The Onan Quiet unit is also front servicable, except for the fuel filter which needs a contortionist and removal of half of the casing to get to. The seller advised me to remove the factory one and move it to somewhere more accessable.
It is in its own sound proof box but I will add some soundproofing to the bay anyway. It takes in its air supply and exhausts it from below, so that simplifies that part. Just need to duct it to keep out water, road dirt, etc and to not blow dust as one drives through parking lots. I am not sure how much heat it will produce through the casing, I haven't found any info on that aspect of the unit as yet, so I may have to use a fan in the bay to keep things cool.
Oh and Henry, what was that formula again for weight distribution? I have mislaid it. Thanks.
Peter. |
Henry R. Bergman, Jr. (Henryofcj) (63.164.175.89)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 15, 2002 - 7:57 pm: | |
Oh gosh Peter, I was afraid someone would call me on that one. Hoist by my own Petard! He he he!
Well, as the young person sosss patiently tried to teach me, it is all a matter of proportions and relationships..... Hang on....long post.
An example; if a large diesel apu of 656 pounds is centered (gravity or center of mass wise) 72 inches in front of the rear axle and 24 inches out from the centerline on the passenger's side...
And the wheelbase is say, 220 inches and the front track is, let's say 78 inches and the rear track 66 inches, then...
One can calculate how much each axle end front to back and side to side is going to be affected. ...Got to go to my car and get my Radio
Shack $5.00 calculator....
Ok, since the apu is between the axles, we already can assume that each axle will have some weight added to it. Now lets see how much will go to each corner.
Take 220 inches and subtract 72 inches from it. This gives you 148 inches from the apu to the front axle.
72 over 148 times X over 100 will give you 48.5% of the weight on the front axle, which means also that 51.4% will be on the back axle. OK so far? This is giving ME a headache. Hang on.
Now we can figure how much will be on the Right and Left sides too. This is also easy to do--heck I can do it. I am even left handed.
Let's do the front axle first. Since the front axle track is 78 inches, that means the distance from the centerline to each end is one half of that, or 39".
We already know that the apu sets 24 inches out from the centerline on the passenger side. Subtract 24" from 39" to get 15". Then take 15 over 78 times X over 100. This is because the apu rests inside the track dimension.
This gives you 19.2% of 48.5% of the apu weight on the left front tire (driver's side) That means 80.8% of 48.5% is on the right front tire (passenger's side)
The back weight side to side goes the same way. The rear track is narrower because of the duel tires. I am guessing 66". Actual measurement may be different.
Sosss.... do the same thing to the rear. One half of 66" minus 24" equals 9". Then do 9 over 66 times X over 100 which equals 13.6% of 51.4% on the left rear which means 86.4% of 51.4% rests on the right rear.
Then do the math. Looks like the RF 257, LF 61, RR 291, LR 47. The total should equal the weight of apu which is 656 pounds. Let me proof read this.....
I think it is good. Also there is a factor that we have NOT used which relates to the ratio of the different front and rear tracks. Don't even pretend I understand THAT. The kid does. Good luck and sorry I was soossss long winded. Good luck. |
Buswarrior (Buswarrior) (64.229.212.168)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, August 15, 2002 - 10:52 pm: | |
Something to think about...
The new coaches have pushed the AC and the fuel tank heavily towards the rear instead of the historical configuration of these items being hard up behind the front axle. Part of the problem is the longer wheelbase on the 45 footers and the manufacturers trying harder today to keep the front axle within legal limits when loaded than what they might have in days gone by.
The problem? The new coaches are a real handful to keep in the lane in a heavy crosswind because there is so little weight on the front, relative to the side area and weight on the rears. My MC8 with the sloppy old ram steering, a full tank of fuel and many many miles on it is nicer to drive in a crosswind than a new MCI Renaissance or Prevost H3-45 full of fuel and people.
I would advocate keeping an eye on the front axle weight, but don't worry about putting all your weight heavy to the rear, you might end up with it being less pleasurable to drive in crosswind conditions, never mind it's stability in the snow!
Don't be afraid to load up the front axle close to the axle rating. Do be thoughtful with your fluid tank placement: Your fuels leave as you use them, lightening up the coach, but your fresh water moves to the waste tanks. As long as you haven't done your figuring and forgot that the empty 700 gallon waste tank lurking in the front hold could eventually transfer that 7000lbs of water in the rear hold forward, you'll be fine.
Here's why you really shouldn't worry too much:
Ever wonder what two holds packed completely full of the big weekend newspapers, the other hold packed tight full of luggage, more suitcases in the parcel racks and in the aisle and 47 people in the seats on the midnight red eye pulling out of the big city might have weighed on each axle?
Year in year out with no problems, every big city in North America, every major fleet, with every big newspaper aboard.
Ever wonder why buses don't go into the scales?
Maybe it's best we don't wonder.
So, put a good set of steer tires under your conversion, and don't worry about the weight on the steer axle, just be thoughtful.
Lots of better things to use your worry on!
happy coaching!
buswarrior |
Peter Broadribb (Madbrit) (170.215.36.232)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, August 16, 2002 - 5:08 am: | |
Thanks Henry,
Sorry to have given you a headache, all is now clear that it is just a matter of percentages, gee and I thought it going to be a complicated formula....... LOL.
Buswarrior, you are probably right about more weight on the front. We do have to bare in mind that most of us have removed the a/c and heavy fan motors, also the heater core and condensor. Also, maybe moved the start batteries to the back and so that is already a great part of the genset weight accounted for. Now using Henry's calculations, we have to allow that for anything we move to the back behind the rear axles, such as those batteries, makes a really big difference.
If the water tanks are kept in the same vacinity, the movement of liquids from one tank to another should not be too much of a concern. My idea is to have the fresh water under the foot of the bed and the grey and black in the rear bay. The generator being forward of that with the house and start batteries in the same bay, so that two of the heaviest stable weighted items are fairly well balanced.
Peter. |
Molsdorf (208.18.102.109)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, August 16, 2002 - 9:24 am: | |
Ross, this might help on that 22/24 math problem;
Here is a method I used to put one in that small A/C compartment door (so it would also ventilate) .
I put it on a slide and made a swivel plate (on top of slide arms) so it would turn, then when pulled out you can swivel it to work on, now what you do need to gain 2-3 inches in length is make a box opening to the adjoining compartment, when you start to pull it out or in, just pull the pin on the swivel plate so that it will start to rotate when pulling out or in and you have all the clearance you could want, plus you have a well vented compartment and you can get to all the components with ease. The swivel plate was two plates which I milled a circle in each (matching) put in a hand full of wheel bearings which I got from a truck axle thrown away at a repair shop. Bingo a swivel plate that only added 1 1/2" to height. |
Henry R. Bergman, Jr. (Henryofcj) (63.224.197.10)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, August 16, 2002 - 4:05 pm: | |
Peter, what I forgot to say too was that if a weight is placed BEHIND or IN FRONT of the rear or front axle the same math applies with just a few changes.
This is because since the added items are outside of the 4 corners, some extra weight is going to be added to one axle and actually some weight is lifted OFF of the other axle.
The total weight increase the chassis experiences is the same, only the makeup of the weight is different. Sorry I did not mention this--the kid knows this also.
My Crown right now (stripped shell) only has 9400 pounds on a 16,000 front axle which I can legally (?) load to 14,400 pounds with the 12R x 22.5 18 ply tires. The steering is a little vague.
Right now the calculations indicate that the front end may end up weighing around 10,750 to 11,000 full load curb weight with no people. I might consider adding some more front end weight to tighten up the steering.
Getting the weights and balances correct for the various static and dynamic loads has been real fun, let me tell you. Seems I have studied over 12 different ideas on how and where the fuel, water and holding stuff will all go.
Yea, you burn fuel. You kinda usually only transfer the water around as gray and black. It all makes a difference where stuff ends up being installed on the coach. Then you have to add people to the equations too. Are we having fun yet? I need a beer!!! Thanks. |
Henry R. Bergman, Jr. (Henryofcj) (63.224.197.10)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, August 21, 2002 - 8:30 pm: | |
Peter;
Very sorry to have to report that my math on the weights and balances was INCORRECT!!!
The error is very subtle (added rather than subtracted) and I do not have time right now to give you the CORRECT equation.
I only discovered this when rechecking my own figures on my own coach conversion calculations and found they were not quite correct.
Tomorrow or Friday when I have the time, I will post my error and try to give the CORRECT way to do the math.
Sorry to have posted the wrong stuff. Only found out about it a few minutes ago. Will correct it. Suicide an option. AHHHHHAGGHH! Henry |
Henry R. Bergman, Jr. (Henryofcj) (63.224.197.10)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, August 26, 2002 - 3:30 pm: | |
Peter;
If a gen set is located 72" in front of the rear axle and the wheelbase is, lets say, 220 inches, here is the way the math SHOULD GO!!
72" over 220", NOT 72" over 148" This is embarrassing. I did not catch it at the time and I am sorry. Oh well, live and learn.
The rest of the weight and balance math is, I hope, correct. The Kid who tried to teach me this is shaking her head. Seems I flunked math again. |
Peter Broadribb (Madbrit) (216.67.216.37)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, August 27, 2002 - 12:43 am: | |
Henry,
Thank you for your correction. I will add this to the already bulging bus info file I have. I wish I had a budding mathematician handy to help out with another set of fingers and toes.
Peter. |
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