Need Help!! About to Buy!!!!

[KevinDarcy11]

When saying "big buses" is that going to be everything larger than a shortie?

This forum is so great. Definitely a bit overwhelming but knowing there is a community here to help is incredible. Thanks again for all the info, everyone!

Last question and I think I will have most questions answered. Are hours OR miles on an engine more important? I truly don't know how this works. It looks like from google research most engines need to be rebuilt around ~9000 hours?

[cadillackid]

Originally Posted by PNW_Steve

I mostly agree with Marc.

I do feel a little different about the Cummins 5.9.

I have owned several 5.9's and in the right application it is one of my favorites. In a shorty, I would take a 5.9 over a T444e.

In a full size bus I would stick with an 8.3 or DT-466/530 and either an Allison 2500, MD-3060 or MT-643.

If by any chance you happen across a 5.9 powered 5-6 window please ping me?

my shortie with a 444E will Smoke a 5.9 and probably a lot of the DT466E out there

[PNW_Steve]

Originally Posted by cadillackid

my shortie with a 444E will Smoke a 5.9 and probably a lot of the DT466E out there

Dunno...

I have a 10k LB rig that is 22.5' long with a 5.9 that may give you a pretty good challenge.

I have not owned a T-444E. I have had a couple of Powerstrokes and, again, my preference is for the I6's. There are lots of great T444 and GM 6.6 Duramax that do a fantastic job. My preference is for I6. If you want big displacement then the 8.3 is another great engine.

I will make an exception for the DD two strokes. No logic there. A modern I6 four stroke is superior in so many ways. I just love a two stroke DD.

[cowlitzcoach]

Most school buses rack up, on average, 10K miles per year over the service life of the bus. Most will rack up a lot more miles when new and the gradually fewer miles as the bus is moved off of long runs to short runs to the spare line.



Hours on a bus is a little hard to average as a bus with A/C in FL will probably run a lot of hours while not going anywhere a lot more than a bus in WA will run to keep the heater going. 20 MPH average is not uncommon for a school bus. If the average is lower it means it has spent a very large percentage of the time not moving which is hard on an engine. If the average is higher it means it spent a higher percentage actually moving. Some trip buses will have a crazy number of miles but relatively low engine hours.



At the end of the day you need to determine what will work the best for you. If the price is attractive enough spending the $$$$ later to rebuild an engine/transmission might be less expensive than purchasing a bus that appears to be better for a higher price.

[KevinDarcy11]

Is there an average on the amount of hours until a rebuild is necessary? I requested maintenance records as well to see if any overhaul was done.

[Sleddgracer]

PNW_Steve - could you expand on that please? - no gas or propane?? - I have my eye on a 'possible' skoolie purchase, right size, already registered locally as a motor home, that has been converted to propane and the owner claims gets 'good mileage - I also have my eye on a moderately low mileage fairly high end motorhome that has water damage with a 454 and Ram Air - repairing water damage is the least of my worries

[o1marc]

Originally Posted by Sleddgracer

PNW_Steve - could you expand on that please? - no gas or propane?? - I have my eye on a 'possible' skoolie purchase, right size, already registered locally as a motor home, that has been converted to propane and the owner claims gets 'good mileage - I also have my eye on a moderately low mileage fairly high end motorhome that has water damage with a 454 and Ram Air - repairing water damage is the least of my worries

My research shows propane gets worse mileage, but cost less so there's a benefit at the end. I don't think propane delivers as much power either.

[o1marc]

Originally Posted by Sleddgracer

PNW_Steve - could you expand on that please? - no gas or propane?? - I have my eye on a 'possible' skoolie purchase, right size, already registered locally as a motor home, that has been converted to propane and the owner claims gets 'good mileage - I also have my eye on a moderately low mileage fairly high end motorhome that has water damage with a 454 and Ram Air - repairing water damage is the least of my worries

Rebuilds are usually determined by mileage , not hours. Many motors get 300k-500k miles before normal rebuild is needed. One with low miles yet extremely high hours may need it sooner.

[cowlitzcoach]

Originally Posted by Sleddgracer

PNW_Steve - could you expand on that please? - no gas or propane?? - I have my eye on a 'possible' skoolie purchase, right size, already registered locally as a motor home, that has been converted to propane and the owner claims gets 'good mileage - I also have my eye on a moderately low mileage fairly high end motorhome that has water damage with a 454 and Ram Air - repairing water damage is the least of my worries

The problem with all of the gas/propane powered buses up until the last few years is they were under powered and gas hogs. 4-5 MPG with an automatic was great fuel mileage compared with 8-11 MPG with a diesel in the same size bus.

[EastCoastCB]

Originally Posted by o1marc

My research shows propane gets worse mileage, but cost less so there's a benefit at the end. I don't think propane delivers as much power either.

This is my understanding as well.

[Sleddgracer]

Originally Posted by cowlitzcoach

The problem with all of the gas/propane powered buses up until the last few years is they were under powered and gas hogs. 4-5 MPG with an automatic was great fuel mileage compared with 8-11 MPG with a diesel in the same size bus.

has anyone figured the cost of repairs into it? - lots of cheap parts and experienced mechanics when it comes to a chevy 454 - not so much when it comes to diesels - I always figured you had to count on adding a "0" to the cost of fixing a gas engine when it came to fixing a diesel - I would welcome alternative thoughts

[Brad_SwiftFur]

Originally Posted by KevinDarcy11

When saying "big buses" is that going to be everything larger than a shortie?

Last question and I think I will have most questions answered. Are hours OR miles on an engine more important? I truly don't know how this works. It looks like from google research most engines need to be rebuilt around ~9000 hours?

Originally Posted by KevinDarcy11

Is there an average on the amount of hours until a rebuild is necessary? I requested maintenance records as well to see if any overhaul was done.

Hours/miles are kinda subjective. Were the miles freeway cruising on flat land? Heavy stop and go in the mountains? Long trips? Lots of start ups and shut downs? Get the idea?

Originally Posted by PNW_Steve

Dunno...

I have a 10k LB rig that is 22.5' long with a 5.9 that may give you a pretty good challenge.

I have not owned a T-444E. I have had a couple of Powerstrokes and, again, my preference is for the I6's. There are lots of great T444 and GM 6.6 Duramax that do a fantastic job. My preference is for I6. If you want big displacement then the 8.3 is another great engine.

I will make an exception for the DD two strokes. No logic there. A modern I6 four stroke is superior in so many ways. I just love a two stroke DD.

One thing about the DD 2-stroke engines is that they produced power on each stroke of the piston, as opposed to every other stroke on other engines.


The V-8 style T444 (and it's "E" variant) and other V8 style diesel engines (excluding the DD 2 stroke) is that they simply don't generate as much torque as most straight 6's do. Consider this ... a racecar might generate 600 horsepower. It will accelerate quickly, have a high top speed, and the engine will spin many RPM's ... but don't last long, and don't generate much torque. A big truck might have a 600 HP engine (Cummins ISX for example) and won't accelerate as quickly and certainly not have as much top speed, but it will haul absurd amounts of weight up steep hills. It'll have a top RPM much lower than the racecar, and may last over a million miles. A locomotive may also have a 600 HP engine (old switcher type), have a redline of 900 RPM, but generates *GOBS* of torque ... enough to move a number of heavily loaded railcars.


In our world, horsepower comes second to torque. The two are related mathematically but ultimately it translates to an old racer's saying. "Horsepower determines how fast you can go, torque determines how heavy of a trailer you can pull." Compare a T444 and DT466. Engine displacement is fairly close, but the DT466 only has 6 cylinders instead of 8. Each will have a larger diameter, and more importantly for generating torque, a longer stroke. The 8.3 Cummins simply has a larger displacement than the DT466, and the potential for more torque (depends on how they are spec'ed and programmed). An L10 Cummins, M11 Cummins, N14 Cummins will each have more displacement (respectively) and each could generate more power. (And yes, the N14 was listed as factory engines on some school buses!)

Originally Posted by Sleddgracer

PNW_Steve - could you expand on that please? - no gas or propane?? - I have my eye on a 'possible' skoolie purchase, right size, already registered locally as a motor home, that has been converted to propane and the owner claims gets 'good mileage - I also have my eye on a moderately low mileage fairly high end motorhome that has water damage with a 454 and Ram Air - repairing water damage is the least of my worries

Originally Posted by cowlitzcoach

The problem with all of the gas/propane powered buses up until the last few years is they were under powered and gas hogs. 4-5 MPG with an automatic was great fuel mileage compared with 8-11 MPG with a diesel in the same size bus.

Originally Posted by Sleddgracer

has anyone figured the cost of repairs into it? - lots of cheap parts and experienced mechanics when it comes to a chevy 454 - not so much when it comes to diesels - I always figured you had to count on adding a "0" to the cost of fixing a gas engine when it came to fixing a diesel - I would welcome alternative thoughts

Here in the states, Propane is fairly uncommon for highway use. There aren't many refueling stations and it's partly because the EPA has stringent regulations on propane conversion kits. They simply never became popular. It is my understanding propane is much more common in Canada, and may be a more feasible alternative. Propane engines need far fewer oil changes (I've heard of some going 50K between oil changes).


The thing is, diesel engines, by their very design, use inherently less fuel than their ignition based competitors. The latter require a specific fuel-air mixture at all times, where a diesel intakes plain air, compressed to a high temperature on the compression stroke, and just enough fuel injected to meet the load. There may be unused air if the engine is idling. Also, diesel has more heat energy per gallon than gas does (About 20% IIRC), thus less is needed for the same amount of power.

[Ronnie]

Originally Posted by Sleddgracer

PNW_Steve - could you expand on that please? - no gas or propane?? - I have my eye on a 'possible' skoolie purchase, right size, already registered locally as a motor home, that has been converted to propane and the owner claims gets 'good mileage - I also have my eye on a moderately low mileage fairly high end motorhome that has water damage with a 454 and Ram Air - repairing water damage is the least of my worries

Can always convert back to gas from propane. The other thing to think about is the price difference between gas and diesel. 80 cents a gallon around here but more in other places, $1.20 a gallon difference is the largest I have seen. So cost per mile needs to be figured rather then miles per gallon.

[KevinDarcy11]

Definitely understand. I'm assuming since it was a FL bus and with the type of transmission in it, it would have been used for a lot of stop start. With the amount of hours and the set up on this particular one gonna have to say NO! Ha, thanks for all the help, you all are a wealth of knowledge!

[EastCoastCB]

Originally Posted by KevinDarcy11

Definitely understand. I'm assuming since it was a FL bus and with the type of transmission in it, it would have been used for a lot of stop start. With the amount of hours and the set up on this particular one gonna have to say NO! Ha, thanks for all the help, you all are a wealth of knowledge!

Fl isn't a great place for buses. High prices and low spec. Mostly cannibalized hulks when FL is done with em.

[Miles O Roads]

Is propane and cng the same. Don't know anything about them but seen a lot of blown up deere motors in buses for sale on cng. I assume natural gas? As said I would stay away from propane if your traveling.

[Ronnie]

CNG is compressed natural gas, and is lighter then air
Propane is refined from oil and is heavier then air. The fuel mixture is a little different, so you can not switch back and forth without adjusting the fuel mixture.

[KevinDarcy11]

ONE MORE QUESTION!
What do you guys think of an 01' Thomas Freightliner, Cummins, Allison 2000 ~170K miles, 10K hours???

[PNW_Steve]

Originally Posted by KevinDarcy11

ONE MORE QUESTION!
What do you guys think of an 01' Thomas Freightliner, Cummins, Allison 2000 ~170K miles, 10K hours???

What size is the bus? Which Cummins engine?

The Allison 2000 is a very good transmission for our application.

[KevinDarcy11]

65 passenger Cummins 5.9 I believe