I want to lower the floor in a School Bus. Start with what chassis?

Carwhisperer · July 05, 2016, 05:44:09 PM

I'm looking to build a rolling diner of sorts. I want it to have a drive up window. At this point I am focused on a School Bus theme, although I would consider other options, maybe even a double decker. It must have vintage character. Right now I'm thinking a mid engine Crown might be the best option. These busses have more of a space frame than a ladder frame, right? If so, I was thinking I might reconstruct the frame to lower the floor on the curb side all the way between the front and rear axle. (My understanding is that the engine lays down on the driver's side) All of that area could then be used for the kitchen and I could also put the drive up window in that vicinity. A drive up window needs to be pretty low. Usually, the workers are standing at about the same level as the surface the vehicles are on. I could probably get away with 12-18 inches off the ground max. A bus on air bags would be ideal, but I don't believe many school busses came that way. Although I'm sure anything could be bagged. I was thinking I could also add a door behind the rear axle, on the driver's side. I would have a couple of small tables in that area for sit down patrons. I am thinking I would want at least a 36 footer. I would want the bus to still be mobile, although removing the drive train would be an option that would add a lot more available space. I was thinking a triple axle bus, in which one of the rear axles was removed, would also free up a lot of space.

Incidentally, in 1999 I converted a Flxible 31 foot city bus into a motorhome. During the conversion I wrote an article about replacing the PT injector pump on the Cummins triple nickel, which was published in the hard copy version of Bus Conversions Magazine. I even got a T-shirt for my trouble! I haven't been around busses much since then but have built and owned many RV's.

So any thoughts and input are/is invited!

chessie4905 · July 05, 2016, 06:05:05 PM

It would probably a lot easier to use a GM RTS. Engine in rear out of your way. Already has air suspension.

gumpy · July 05, 2016, 06:32:20 PM

More recent city buses have flat floors that are very close to curb level when the suspension is lowered. Seems like a better candidate for what you describe.

Lowering the floor in a frame mounted skoolie seems like a lot of work, and then you have to deal with climbing up and down when cooking vs serving.

Just my thoughts.

HB of CJ · July 05, 2016, 07:08:15 PM

A mid engined Crown Supercoach would be very difficult to lower. The frame is a custom laddered chrome moly box type with two, (2) big boxed members down the middle saddled with boxed lateral supports. Very strong and stiff.

The aluminum body is bonded to many 4130 supports and the whole separate body is bonded to the steel frame. The undersides of a Twinkie Crown is very busy. The 855 Cummins engine is huge. Hangs from frame on left side at 70%.

The interior bus floor is 1.5" redwood plywood. The seats bolt through the floor. No room for dropping. The Cummins can be raised a few inches but takes time and effort. Ground clearance on a Crown Supercoach is limited to a few inches under the skirt.

Then add either the Allison or Fuller tranny. One big 100 gallon fuel tank usually in two, (2) possible locations. Usually the frame stops at the rear axle leaf spring mounts. The post 1976 and later models were very heavily constructed indeed.

Add in the very large drivers side radiator. Two 8D batteries. An oversize air cleaner box. A big muffler behind the engine. There is just not much room left. Most Crowns had only 1 or 2 side truck locations using just one plus maybe a rear trunk.

Like already said, it might be a lot easier to find a proper ex transit model with the kneeling front option. Transits are very heavily built. Worst possible duty. Stop and go. Finding the exact proper one will take fun, madness and lots of cool research.

Carwhisperer · July 05, 2016, 08:26:45 PM

Thank you for the input! I see what you mean about all the stuff in the way on that side. When you say the Cummins hangs at 70%, do you mean that it occupies 70% of the width of the bus. In other words, I could only lower 30% of the floor on the curb side of the engine? Or do you mean it is 70% toward the back? I would think it could only occupy 1/2 the width of the bell housing past the centerline of the bus onto the curb side, presuming the driveshaft goes down the centerline.

How about this idea? Take a front engine bus with a really long rear overhang, and lower the whole frame behind the rear spring hangers? I wouldn't think there is much back there besides the exhaust and maybe a spare tire. 10-20 year old versions of these seem to go pretty cheap. I've seen some that have the hood, fenders and grill that are relatively modern looking, while the rest of the bus is just a box. Perhaps I could replace that front clip with a vintage 5 ton truck front clip, like a 50's Chevy, Ford or International, and end up with a pretty vintage looking bus with more modern mechanicals.

LuckyChow · July 05, 2016, 08:32:46 PM

You'd be light years ahead to consider a low floor transit.

RJ · July 05, 2016, 09:10:42 PM

Food for thought (pun intended):

http://www.bargainbusnews.com/Buses/8365-1966LeylandLeyland/#imgiframediv

http://britishbuscompany.com/bus-sales/

http://www.ebay.com/itm/Double-Decker-Bus-For-Sale-LEYLAND-TITAN-PD2-/331897238246?forcerrptr=true&hash=item4d469df2e6:g:UNUAAOSwgY9Xde1C&item=331897238246

http://forums.roadfood.com/Advice-on-building-a-food-truck-using-a-British-doubledecker-sought-m640574-p2.aspx (Scroll down and read PhilV's comment.)

FYI, the pancake engine in a Crown takes up the entire space between the frame rails. The amount of space between the frame rail and the body is reduced even more due to engine plumbing (air filter, intake, turbo, exhaust and muffler) outside the rails. Besides, since so many Crowns are now being crushed, rather than sold (due to Californication's idiotic political climate), the Crown Coach Junkies would have apoplexy if you were to modify a Twinkie Crown the way you're thinking of doing.

As already mentioned, a low-floor transit might be an excellent prospect - quite a few are coming up for auction from various transit properties, and sometimes sell for scrap metal prices.

FWIW & HTH. . .

easystreet · July 05, 2016, 10:13:43 PM

Crown built a few rear engine Supercoach look a likes towards the end when they were trying to offer a more price competitive schoolie. I had one in a district where I was Transportation Supervisor. Had 250hp Cat 3208 w/ Allison. Had standard baggage compartments underneath much like a Gillig schoolie. Really was a very nice driving unit. Was our primary trip bus at the time. If your after the Crown look, and could find one, it probably would be a better candidate for what your thinking.

scanzel · July 06, 2016, 03:10:44 AM

A lot of transit's on Ebay under buses.

Iceni John · July 06, 2016, 07:36:57 AM

Quote from: easystreet on July 05, 2016, 10:13:43 PM
Crown built a few rear engine Supercoach look a likes towards the end when they were trying to offer a more price competitive schoolie. I had one in a district where I was Transportation Supervisor. Had 250hp Cat 3208 w/ Allison. Had standard baggage compartments underneath much like a Gillig schoolie. Really was a very nice driving unit. Was our primary trip bus at the time. If your after the Crown look, and could find one, it probably would be a better candidate for what your thinking.

Like mine?

John

TomC · July 06, 2016, 08:50:28 AM

I have the perfect bus for you. It is a low floor transit with a rear left side mounted engine-usually using a Series 50 Detroit. Yes the engine is mounted fore and aft, but on the left side of the bus-you open the side panel and the engine is right there. Then that leaves the right side of the bus completely open for your right door behind the rear axle for seating, and the floor is low in the center for the kitchen, has air suspension that you can put dump valves on it. Don't fool with any other bus-this is perfect! We have some still running in Los Angeles-not quite sure the manufacturer of the bus. But since they are straight Diesel, I'm sure they will be retiring them soon in favor of new natural gass. Good Luck, TomC

opus · July 06, 2016, 09:02:23 AM

I've been watching transits sell for $1500, nice clean units, 8.3 Cummins most of them. Lots of miles and hours on them but for what you want it should be fine.

TomC · July 06, 2016, 10:23:32 AM

The rear side engine low floor transit is an Orion model VI with Series 50 engine made from 1995-2004. Good Luck, TomC

DoubleEagle · July 06, 2016, 10:40:10 AM

Yes, consider the GMC RTS, it still looks good after all these years, they are cheap, and the floor is low. I drove one for a while, and it handles nicely. You could spend a lot of time and money trying to reinvent a school bus, and it will end up looking less than professional.

Carwhisperer · July 08, 2016, 09:17:09 PM

Thanks for the replies and practical suggestions. That routemaster that is set up as a restaurant would be real interesting if the kitchen was on the bottom and seating on top. But I'll think about it anyway. I agree a low floor transit would be good for the height issue, but they don't have the character I'm looking for. But I haven't entirely ruled one out. I got an opportunity to look at a 3 axle mid engine Gillig today, and I see what you mean about how much room that engine intrudes onto the passenger side. I think I could move a lot of that stuff. The fuel tank for sure. I didn't get a chance to take any measurements though.