Long Bus Body Modifications?

jackofallmasterof0 · 01-02-2017, 08:30 AM

Hey guys, new to the community, but an old hand at fabrication and modification. I've worked in sales, installation, repair and customization for mostly cars and light trucks for the last 15 years. Built carbs for NHRA and NASCAR racing, maintained Italian exotics, built renovations and expansions on homes, rebuilt interiors in modern euro luxury cruisers, but it all started building hotrods with my dad nearly 20 years ago. Recently I got into bigger stuff when I started maintaining a small fleet of Mercedes Unimogs, 1960's era monster military vehicles. So I feel fairly confident I have the needed skill set and a friendly place to work at my old mans new garage on 5 acres.

I would like to find a Bluebird TC2200 style long bus ideally, but am open to other suggestions, I have a preference for Cummins engines due to past good experience with them on tow rigs, won't touch a Ford, even for free. I would like to know how well the long busses bodies hold up to modification, specifically, the sides between the wheel wells front and rear? If cut and modified how much reinforcement will they need? I see a lot of rooftop mods for decks and expanded sleeping quarters, but would prefer to allocate rooftop space to solar panels and and experimental vertical axis wind generator I've been working on.

Thankyou for any imput, E.

Tango · 01-02-2017, 08:56 AM

Welcome jack-o --- Sounds like you were made for a bus rebuild! Blue Birds are famously overbuilt and very solid platforms. To me, the biggest trick when modding is to keep the whole structural system working together. By that I mean making sure any loads are properly transferred. I raised the roof on my old 40 footer but only after talking with a retired BB engineer. He was adamant about maintaining the original caps (at both ends) as well as the interior roof skin. I had to bridge a couple of very large openings for RV windows and made sure to tie everything back together as well as possible. But as you probably know, it is possible to overdo it which only creates weak points on each side of any work. Buses, and especially skoolies, like to flex. Keeping that ability to me is the hard part and without consulting a design engineer, all I could do was try and think through how various loads would transfer. On the other hand, these structures seem to be fairly forgiving as I have seen some rigs with years on the road with mods that would never have imagined would last a week.

Best of luck on your search and keep us up on your progress.

jackofallmasterof0 · 01-02-2017, 09:06 AM

Thanks for the advice, my family had a Bluebird RV (440RB Chrysler) many years ago and it was a tank, not like the flimsy things I do interior work on occasionally, the fiberglass roofs and enclosures that wobble in a strong wind are the worst. School busses in particular have attracted me for their durability, many serving for decades without major structural or mechanical failure.

Your note on their bodies liking to flex is important, I will have to explore that further. What I would like to do is take a section out of each side between the wheel wells, maybe 6 to 8 feet of the bus to create space to recess a small deployable deck and sunshade on each side. I guess my questions there is will it be better to build out a frame and mount the deck to the body, and allow it to flex with it, or mount the decks to the frame, and let them float and flex independently, may cause problems with sealing there.

Tango · 01-02-2017, 09:30 AM

Somewhere I have seen a pic of a bus that had a fold down deck simply attached to the side. Only stuck out about an inch and a half when folded up. And as I recall ran from the entry door all the way back to the rear wheel cutout. Appeared to have a cable system for lowering and fold out legs to stabilize it when docked. Awning attached over it all. No idea whether the width regs were an issue or not but there are buses and other rigs that are over a hundred inches wide these days.

cowlitzcoach · 01-02-2017, 11:50 AM

I am not sure what part of the bus between the axles you are referring.

If you are referring to the area below the floor line, none of that is structural. Any modifications there are just in flat panels supported by bent sheet metal bracing.

If you are referring to the area between the floor line and the drip rail, each window post is structural. There is a one piece roof bow that runs from the floor up and over the roof and back to the floor on the other side. Roof rails are threaded onto the roof rails and run in one piece from the front header to the rear header. In other words a LOT of steel framing to keep things straight and to keep things from crushing in the event of a rollover crash.

Newer buses are not built nearly as strong as older buses. Crown advertised their frame rails were made out of 150,000 PSI steel. Blue Bird, IC, and Thomas advertise the frame rails they use today are made out of 50,000 PSI steel. A frame that is made out of 50,000 PSI steel will move a lot more than a frame that is made out of 150,000 PSI steel.

If you want to open stuff up to add slide outs it shouldn't be a problem as long as you reinforce and support the openings.

I have seen more than a couple of burned out hulks that were the left overs of some high end rear engine Class 'A' moho's. I have always been struck by how little steel framing went into them. One I saw used 1" square tube on 48" centers with the roof structure welded to the top side rail. I wondered what else was there that had been consumed or I didn't see that kept the body from wracking and twisting as it went down the road.

Only you can determine how large of an opening you think will be safe. I do know that in the past Blue Bird, IC, and Thomas have made a lot of commercial versions of their school bus bodies that had transit/coach type windows that eliminated half of the window posts--the windows were more than twice as long as a standard split sash school bus window. Side lift and emergency doors are also much wider than a standard split sash school bus window so I know you can eliminate some of the window posts.

I would start out with an All American, West-Coast-Er Saf-T-Liner, or an IC bus rather than a TC2000 or MVP. The TC2000 and MVP were built considerably lighter than their more expensive brethren and probably won't tolerate as much side openings. At the same time, they are built so much heavier duty than any Class 'A' moho that even if you took out more than half of the window posts you would still have considerably more rollover protection than in a Class 'A' moho.

Good luck and happy trails to you.

jackofallmasterof0 · 01-02-2017, 01:38 PM

I was wondering if those window posts were load bearing, thanks for that. I'm not familiar with Crown busses, can't say I've ever seen one down here, we have tons and tons of Internationals, Freighliners and Bluebirds running around to be had cheap. I've noticed alot of the Bluebirds use Cummins 5.9L I6 engines, but they all seem to be the low power 190hp models. Has anyone had any luck swapping in a 24V 250hp 5.9 out of the large Dodge trucks of that era?

onemanarmy · 01-02-2017, 04:40 PM

What is the ultimate use for the bus? Motorhome?

Sent from my Moto G (4) using Tapatalk

jackofallmasterof0 · 01-02-2017, 04:44 PM

Longterm mobile residence and workspace, will need to tow a light vehicle behind as well. The new job I'm starting will allow me to work for several weeks or months in a set location, so long as I have a reliable internet connection, easy to fin in campgrounds and RV parks these days nation wide. So I want to just explore places, find a new home maybe and settle down when I find the right place.

cowlitzcoach · 01-02-2017, 08:34 PM

If the 5.9L 190 HP engine is not stout enough for you then I would suggest you don't purchase that bus and purchase one that has an engine that is stout enough for you. For what it would cost to purchase a take out engine you could most probably purchase another bus.

It is much easier and less expensive to purchase the bus with your preferred HP and gearing than it is to swap stuff around to get what you want.

One real problem with buses, even those with front engines but particularly so with rear engines, is the cooling systems are not really designed for sustained high speed running but for stop/go route service. Trip buses with the high HP engines and high speed rear end gearing also come from the factory with oversized engines and coolers.

It is far less expensive by a long ways to purchase a bus with your preferred power package and gearing than to swap stuff around and upgrade to meet the new requirements.

jackofallmasterof0 · 01-02-2017, 08:55 PM

I would rather buy a non running hulk and put an engine I trust into it than buy something with a powertrain i'm unfamiliar with, especially when it comes to parts and repairs. The cummins 5.9 is far cheaper to repair than an Internatioal or DT, and more reliable than the Ford and GM engines, and has and extensive selection of aftermarket modifications to improve fuel efficiency and power output at the same time. Also swapping egnines and transmissions is not something I'm unfamiliar with, even on big stuff, it can be done.

As for the cooling system, once again, I don't see this is a big deal, adding larger Radiators, auxiliary pumps, tranny and diff coolers are standard operating procedure for both hotrods and off road vehicles, so I don't see this as a big obstacle.

Rameses · 01-02-2017, 09:18 PM

Why would you swap out a 6BT for an ISB?

Just change the injectors, hot rod the pump and call it a day.

Or better yet, just buy a bus with an 8.3 in it. Almost double the torque output of a 5.9 without doing any mods.

EastCoastCB · 01-03-2017, 05:45 AM

Quote:

Originally Posted by jackofallmasterof0

I would rather buy a non running hulk and put an engine I trust into it than buy something with a powertrain i'm unfamiliar with, especially when it comes to parts and repairs. The cummins 5.9 is far cheaper to repair than an Internatioal or DT, and more reliable than the Ford and GM engines, and has and extensive selection of aftermarket modifications to improve fuel efficiency and power output at the same time. Also swapping egnines and transmissions is not something I'm unfamiliar with, even on big stuff, it can be done.

As for the cooling system, once again, I don't see this is a big deal, adding larger Radiators, auxiliary pumps, tranny and diff coolers are standard operating procedure for both hotrods and off road vehicles, so I don't see this as a big obstacle.

How is the Cummins cheaper?
The DT's can be built in-frame unlike that 5.9 pickup truck engine.

superdave · 01-03-2017, 06:42 AM

Quote:

Originally Posted by Rameses

Why would you swap out a 6BT for an ISB?

Just change the injectors, hot rod the pump and call it a day.

Or better yet, just buy a bus with an 8.3 in it. Almost double the torque output of a 5.9 without doing any mods.

just get the 8.3 in a trip bus, its a great engine with no mods to do. good luck. got any pics of you vertical axis genny. good luck in your search

Deezl Smoke · 01-03-2017, 07:08 AM

If you want a cummins, buy a cummins. They are an awesome engine, and if you are familiar with them, all the better to stick with them and the size you wish to have.
I personally like the cummins, more so the 8.3L. But the Navistar 466 is by no means a dog. It has more capacity for power than any, yes any, 5.9L. They are (arguably I know) just as reliable as a cummins or cat in a bus application. But you have to run what you wish to run or you'll not have that piece of mind that puts a smile on your face when driving it.

Bus body structure is like anything else. It was designed for a specific purpose that statistics showed only needed to meet certain perimeters. This is why there are no cross walls that tie the sides together etc. They're designed to haul persons sitting in seats that are anchored to the floor, and sometimes a small back pack in any over head storage. They were not originally designed for roof rack and a two ton of stuff on the roof, plus cabinets filled with canned food along the ceiling.

If you have a press in your shop, take a short piece of rectangle tube, say a 2x3 or what ever you have, about 2" long and put it in the press to simulate the bus body. Press it. You'll see the sides buckle.
Now take another piece of the same tube, the same length, and tack weld a washer that fits snug into the inside of the tube to act as a cross wall inside the bus. Press it. You'll likely see that the tube with the washer took a lot more work to cause damage, and the damage was less than the tube with nothing but open space.
Maybe not the best analogy, but with your repair experience, I'd think you get the jist of it.

cowlitzcoach · 01-03-2017, 09:21 AM

I am sure you have had a lot of experience upgrading and repurposing stuff. Unfortunately for you most of that experience is not going to help you a lot when it comes to working on buses.

Type 'C' buses would lend themselves to upgrading much easier than any Type 'D' bus.

Type 'D' FE buses have very little room for any modifications to upgrade turbos, intercoolers, radiators, or coolers. The opening up front for the radiator is relatively limited in size and has no room for expansion in height, width, or depth.

Type 'D' RE buses have room for modifications but have the added challenge of dealing with the engine at the rear of the bus and the problems inherent in dealing with air flow into the engine compartment.

I am not saying it can't be done.

I am not saying that you are not capable in making changes.

What I am saying is why go to all of that trouble when you can find a trip bus with a big HP engine and highway gearing that is already set up to go fast? Trust me, you will be many $$$ ahead of the game than if you were to purchase a non-running hulk and repower it.

jackofallmasterof0 · 01-04-2017, 10:30 AM

Quote:

Originally Posted by EastCoastCB

How is the Cummins cheaper?
The DT's can be built in-frame unlike that 5.9 pickup truck engine.

My experience is based on wheeling, mudding and rock crawling with a coworker, they guys running DT, International and Caterpillar rigs constantly complained of the cost and lack of availability of parts, especially when wheeling out in the boonies, your average rural auto parts store simply does not stock them. But you can find 5.9 parts in just about everywhere.

jackofallmasterof0 · 01-04-2017, 10:32 AM

Quote:

Originally Posted by superdave

just get the 8.3 in a trip bus, its a great engine with no mods to do. good luck. got any pics of you vertical axis genny. good luck in your search

I've heard a little about the 8.3's, and I know they share design architecture withthe 5.9's, but how do they compare in terms of availability of parts, is there much interchange between the two, in things like accesories, oil and fuel pumps. Sorry, no pictures of the VAWT, it's staying under wraps until the prototype is finished.

jackofallmasterof0 · 01-04-2017, 10:40 AM

Quote:

Originally Posted by Deezl Smoke

If you have a press in your shop, take a short piece of rectangle tube, say a 2x3 or what ever you have, about 2" long and put it in the press to simulate the bus body. Press it. You'll see the sides buckle.
Now take another piece of the same tube, the same length, and tack weld a washer that fits snug into the inside of the tube to act as a cross wall inside the bus. Press it. You'll likely see that the tube with the washer took a lot more work to cause damage, and the damage was less than the tube with nothing but open space.
Maybe not the best analogy, but with your repair experience, I'd think you get the jist of it.

Good analogy, don't have a press, but have worked with them in the past. I would expect to do some reinforcing when adding things like roof racks, or modifying the body, it's SOP for antiques the had wood reinforced body panels originally.

jackofallmasterof0 · 01-04-2017, 10:55 AM

Quote:

Originally Posted by cowlitzcoach

I am sure you have had a lot of experience upgrading and repurposing stuff. Unfortunately for you most of that experience is not going to help you a lot when it comes to working on buses.

Type 'C' buses would lend themselves to upgrading much easier than any Type 'D' bus.

Type 'D' FE buses have very little room for any modifications to upgrade turbos, intercoolers, radiators, or coolers. The opening up front for the radiator is relatively limited in size and has no room for expansion in height, width, or depth.

Type 'D' RE buses have room for modifications but have the added challenge of dealing with the engine at the rear of the bus and the problems inherent in dealing with air flow into the engine compartment.

I am not saying it can't be done.

I am not saying that you are not capable in making changes.

What I am saying is why go to all of that trouble when you can find a trip bus with a big HP engine and highway gearing that is already set up to go fast? Trust me, you will be many $$$ ahead of the game than if you were to purchase a non-running hulk and repower it.

You have an incredibly negative view of modification of central systems, why?

I'm not talking bout building a 500hp 1000+ft/lb monster, the upgrades I want to include are mostly electronic and take up little to no space. A stock 250hp 5.9 24v can be tuned with little to no modification to existing systems to over 350hp and doubble factory torque while maintaining highway fuel economy. As for the cooling systems that everyone here seems terrified of, it's not a big deal to fabricate new mounting brackets, or simply relocate the unit to a remote location, once again, SOP for both Offroad and hotrod/racing appications.

cowlitzcoach · 01-04-2017, 11:05 AM

The IHC DT family of engines are pretty much trouble free as long as you keep the pH of the coolant as close to neutral as possible. If you do end up having problems parts and pieces for them are available at any Navistar Truck, IC Bus, or International Tractor dealer. The DT family of engines have been used in trucks, buses, tractors, and combines since the 1960's. Of all of the medium duty engines out there, the DT family of engines are probably the lowest in problems.

As far as the Cummins 8.3L/ISC is concerned, it too is a very low maintenance engine. It has been used in many applications just about as long as the 3.9L/5.9L/6.7L (4BT/6BT/ISB) in just about as many applications. I am not sure exactly to whom you have been talking but any parts house that can get parts for 4BT/6BT/ISB parts should also be able to get parts for the 8.3L/ISC.

I would also like to caution you once again about trying to extrapolate your past experience into working on buses. Basic wrenching, welding, and fabrications skills are going to cross over with no problems. But any sort of hot rodding of the power packages is going to be a whole lot different in buses.

While the basic engine is the same the Cummins 5.9/6BT/ISB in a school bus has very little in common with what has been used in Dodge light duty trucks. You also run the risk of trashing the automatic transmission in a bus if you change the HP/torque significantly. The Allison automatic transmissions are built very stout, even the AT540 series of transmissions, and they will go thousands of miles with nothing more than fluid and filter changes. However, that only holds true if the transmission is used within the design envelope of the particular transmission. Each transmission model is designed and built to fit a particular HP/torque range. Within that range it is very difficult to break an Allison. Outside of that range it is very easy to break an Allison.

Which is why I suggest that you find a bus that has the sort of HP/torque you want with the rear gearing you want at the start rather than trying to hot rod a bus. If you increase the HP/torque of the engine you are going to have to increase cooling and more than likely you will have to upgrade the transmission. The addition of extra cooling for the transmission is not going to extend the life of the transmission if you exceed the HP/torque rating of the transmission. Increasing cooling capacity in a bus, particularly a rear engine bus, is a very difficult proposition. Even the bus OEM's struggle to find a way in which to provide adequate cooling. Moving sufficient air from a negative pressure zone to a positive pressure zone requires more than just the addition of electric cooling fans.

All I can say is good luck on your quest. I hope you are successful.

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