cummins 12 valve swap help me

[PNW_Steve]

Sometimes I am amazed at my own ignorance.......

My first bus was rear engine and had a "dropbox" between the transmission and differential to reverse the rotation.

I have also seen RE buses that the engine turned the opposite direction compared to "normal". (RH? LH?)

Now I have to ask..... Why does my Bluebird go forward when I put it in drive and not backwards?

I don't see a drop box and I have never heard any discussion of RH Vs LH rotating engines in school buses.

What am I missing????

[cadillackid]

The ring gear and which side of the carrier the ring is on and how the pinion contacts it will determine which way the axle spins . It could be as simple as a different 3rd member for your axle. I’d have to dig deeper but the concept is the same.
Christopher

[one_eyed_jack]

Originally Posted by PNW_Steve

Sometimes I am amazed at my own ignorance.......

My first bus was rear engine and had a "dropbox" between the transmission and differential to reverse the rotation.

I have also seen RE buses that the engine turned the opposite direction compared to "normal". (RH? LH?)

Now I have to ask..... Why does my Bluebird go forward when I put it in drive and not backwards?

I don't see a drop box and I have never heard any discussion of RH Vs LH rotating engines in school buses.

What am I missing????

I am not familiar with rear eng. set-ups either but unless I miss my guess, if you study the diff. gear carrier, you could find that the pinion gear is on the opposite side to your fr. eng. bus?
Respectfully:
One_Eyed_Jack

[PNW_Steve]

Originally Posted by cadillackid

The ring gear and which side of the carrier the ring is on and how the pinion contacts it will determine which way the axle spins . It could be as simple as a different 3rd member for your axle. I’d have to dig deeper but the concept is the same.
Christopher

So it is the differential that is different?

Are ring and pinion interchangeable with one's that come from FE buses or trucks?

[Ronnie]

Originally Posted by PNW_Steve

So it is the differential that is different?

Are ring and pinion interchangeable with one's that come from FE buses or trucks?

Basically yes the differential is different.

As far as I know it is rare to have a left hand engine in automotive/truck use. However in marine use if a boat has two engines then there will be a right and left hand so that the props turn opposite directions and torque steer is cancelled.

[PNW_Steve]

Originally Posted by Ronnie

Basically yes the differential is different.

As far as I know it is rare to have a left hand engine in automotive/truck use. However in marine use if a boat has two engines then there will be a right and left hand so that the props turn opposite directions and torque steer is cancelled.

Thanks for the info.

Some of the old GM's had reverse turning DD 2 strokes. I agree, much more common in marine applications.

[Crazyhillbilly]

I think it's a sweet idea. Is that a p pump motor or ve can't tell from pic. I would for sure try to do the 4wd. I am building a 49 diamond t bread truck with a power wagon m37 front clip. Using a 12 valve ve pump nv5600 trans np205 t case Dana 80 rear and Dana 60 front with 4:10 gears and lockers hopefully 40 inch tires if they fit nice . Building more of a adventure camper. I put a 12valve in a 56 Chevy bus a couple years back
for a buddy it drives nice I used a nv4500 trans and rear axle out of a 5500 ram it drove nice on highway had plenty of power pulling hills and I got 16 mpg on a 200 Mile road trip he still wants to convert to 4wd so waiting to swap the from axle out

[Booyah45828]

What you do depends on your budget.

I'd keep the engine regardless. You're not going to find a 6bt with a p-pump any easier then what you have now.

If you have the funds, upgrade the transmission. If not, run what you have until it's junk and then upgrade.

All the pusher chassis busses that I've seen would use the same axle housing as a conventional drive, but the differential assembly would be different. You can't just flip it because it's a hypoid gear and won't oil correctly if installed upside down. You can flip the brakes side to side, and then install the correct differential, but it might just be easier to locate an entire axle. Especially if you're looking for different gearing as well(and rear axle ratio is definitely something you should be thinking about)

On the topic of brakes, I assume the dodge is hydraulic while the blue bird is air? That's another tidbit you'll have to work around whether you go all hydraulic or all air. I prefer air brakes in a bus but to each their own.

[Mekanic]

Well I had a great idea for you,... til I saw the donor was a rear engine bus.
Personally if me the I would proceed on this would be to use the 6BT engine & trans combo and then find another front engine bus for the frame and axles.
The rear engine buses have special rear axle gears. ( the ring gear are reverse rotation) They can only be used in rear engine vehicles.

Yes my idea is to mount all that classic sheet metal on more modern frame AND driveline .

[randydupree]

your working on the wrong bus.
Don't screw up a nice BB pusher.

[Bluesky]

You have a nice bus. I like the older style busses. A bus costs money, so might as well spend money on a bus with some style. I say go for it! You can do whatever you want, but consider getting a front engine bus and swapping your body onto a newer frame.

[Seriousracer]

Why not just mount the old bus body on the newer bus chassis. It would be a lot less work

[Tango]

Age will make a big difference. Post war (WWII) bodies are usually fairly easy to transplant onto much more modern chassis & running gear. They are both typically set on parallel rail frames.



Pre-war bodies have a very different configuration in that they and their frames narrow dramatically in front. Getting them to fit onto a modern (post war) "square" frame can be a real challenge. I have seen several that had to be chopped up and widened so much that they lost their original appeal.

[Elliot Naess]

Originally Posted by Bluesky

... ...consider getting a front engine bus and swapping your body onto a newer frame.

Originally Posted by Seriousracer

Why not just mount the old bus body on the newer bus chassis. It would be a lot less work.

What they said!
.

[PNW_Steve]

This is a bit out of my area of experience.....

Can someone explain to me how an FE chassis would be a good platform to move the body to as opposed to a CE?

In an FE the steers are behind the drivers seat. I am trying, without success to visualize how a classic CE body will fit on a modern FE chassis.

Thanks.

S.

[cadillackid]

steve has it right.. it needs to go on a CE chassis.. that said, is the snout long enough to support an inline 6 engine like a 6BT or a CAT-3126?



id be inclined to see it swapped onto a freightliner FS-65 shorty chassis.. mainly becuase the radiator is a bit narrower than on a Navistar at the front... I havent done actual measurements but also seems to be that the front wheels end up in a better spot vs a 3800 navistar.. an IC BE is a possibility .. a small V-8 like the VT-365 might be a better fit than an inline 6 in a configuration like that...



you can use Tango's chevy wayne as a guide.. and the fact an inline 4 is a barely fit and still have room for the radiator, fan, and engine bits within the width constraints of the narrowing snout.. some wider fenders might facilitate the ability to keep the factory hood look up-top while taking advantage of a little more width between the frame for a V-8..



I know no one likes the VT-365 engine, however in a build like this.. one can assume bullet-proofing or refreshing an engine is a given... at least it woud be if I were doing it..

-Christopher

[Ronnie]

In as much as I have had several 47 dodge trucks, Christopher is correct the 6bt will not fit without making a "doghouse". A V-8 will fit, having stuffed one in myself.

[Elliot Naess]

The old body and nose would go on a "CONVENTIONAL" chassis (in the terminology I am accustomed to from trucking).

[Mekanic]

To the OP here is a pic of a what looks like a 52 Diamond T Truck



Build thread here https://www.pirate4x4.com/forum/tow-...truck-144.html
145 Pages.

A Summary:
What happened is the guy that built it started with the 52 Diamond T cab and front sheet metal you see in the pic and a frame that stopped at the back of the cab.
Then that was mounted on a late 80's Uhaul Chassis (7.3IDI-5 speed air ride rear axle)
It was built like this and ran some. Turbo was added to the 7.3 and then He got real
8.3L Cummins Mechanical-allison trans
THen sold

THis is the sort of thing that can be done with old sheetmetal. The main reason fro swapping and entire chassis under a older cab/body is that when you need a wheelbearing or u-joint You won't laughed out of the parts store.

[spiritjohn]

Main reason I'm swapping parts and not planning on switching bus onto a newer chassis is i already live in this bus and it's the only place I can live at the moment so ripping it apart does not thrill me
Also not convinced it would be less work for me either.
These buses are on blocks in the mud. Unsure of how I'd pull that off without using a crane far out of my budget.

Had a bus mechanic tell me the rear differential could be swapped by rotating it 180 degrees as well as switching axles to the other side and also turning third member 180 degrees. He says he has done this successfully several times so since it's what I have I'm going to give that a shot.

Will post more pictures soon, Chevy motor and tranny is out, still getting the Cummins ready to take out and planning on reblocking these buses to switch the axles. planning on shortening the bluebird front axle to make it line up with the frame the same way the original one did. Any advice on that project would be nice, seen a few people do it successfully with other vehicles online