Making them highway friendly........

[plfking]

Originally Posted by o1marc

pattern, couple of end caps and it's in like Flint.

The phrase isn't 'in like Flint', it's 'in like Flynn'.

And locking pliers aren't vice grips, they're vise grips.

[alpine44]

Originally Posted by plfking

The phrase isn't 'in like Flint', it's 'in like Flynn'.

And locking pliers aren't vice grips, they're vise grips.

Thanks for clearing that up. I had googled "in like Flint" but could not make a connection between a feminist takeover plot and fuel savings through better aerodynamics.

[HazMatt]

It wasn't as inapt a word choice as it first seems.
While Errol was smooth and sharp, the cryptocrystalline rock of a similar sounding name may be cleaved to form edges that are sharp and smooth.
Attach it to a stick and poke somebody with it, and it will indeed go in like flint.
I figger it's never too late to learn the dangers of homonyms.
Oh, and Vice Grips are merely nipple clamps for advanced perverts...

[CHEESE_WAGON]

As I've said in another thread here...

These things were never meant to travel over 55-60 in their stock configuration. Can they do it? Sure, doesn't mean it's a good idea. You're driving a 12,000-lb flying brick, plain and simple.

If you really want to make a bus highway friendly, you should start looking through heavy truck and bus salvage yards for a wrecked / burned coach with a nice, big engine and a manual or automatic transmission suitable to your engine/drive configuration, with more than 5-6 forward gears. Might not be so easy making it all work in a skoolie, but there are repower options. Bottom line, you're asking a Volkswagen to be a Porsche otherwise. Ask anyone here who has driven commercial vehicles like this.

Most diesels can be boosted to nearly any power level you want, and most injection pumps can be set to accommodate more power. Your weak link is the transmission, most were designed for low-speed shuttling of school children, not long highway cruises at 70-80 mph. And you really can't expect much from a 12,000-lb vehicle with 200 hp or less and the aerodynamics of a brick.

If you really want to spend the money, a Detroit 60-series with a 10-speed manual and a re-gear to an appropriate ratio (3.23-3.42) will probably get 10+ mpg cruising at 80 all day long in a skoolie, and they are pretty easy to find. And any truck repair shop in America can fix them if repair is needed. Most common engine in trucking. But I guarantee you, the cost will be far beyond any benefit. As I've said elsewhere, consider how much you'll really be driving it.

[o1marc]

Originally Posted by plfking

The phrase isn't 'in like Flint', it's 'in like Flynn'.

And locking pliers aren't vice grips, they're vise grips.

I was referring to the movie.

[Sleddgracer]

Originally Posted by magnakansas

I'll talk about what I did and why.

bus - rounded butt, no roof air or hatches or decks. Why? Trailing side shape for aerodynamic. I know it is not a lot. I also know that, .5% here, 1% there, adds up and does make a difference.

Future modifications include under tray and air dam up front and belly pan along the body, along with tighter fitting fender liners. Yes quite a bit of work for diminishing returns.

I know that at 65mph, my intended cruise speed, I can reduce turbulent air flow under the bus. I might be able to reduce some of the turbulent air flow on the side of the bus. The front? Not a lot that I am seeing, need to do "yarn testing" to find the messy air flow and see what I can do about cleaning it up.

Rear end gearing--- I am aiming to put the engine at lowest engine rpm on flat level ground, with out bringing the engine to a "lugging" condtion.
3.73 rear gears, 245/70-19.5 tires... calculated engine rpm at 65 mph is 1875 rpm. I am changing from 225/70 19.5 and old rear gears were 4.88

engine -- funny thing here is, with diesels, the fuel you burn is the power. So if you burn 100,000 btu per mile with a 5.9 or burn 100,000 btu per mile with a 8.3, or 100,000 btu per mile with a 10.0..... mileage does not seem to vary a bunch with engine size. I have a smaller engine because it fits the engine bay easier. I started with no engine or transmission in my bus.
I have hopped up my bus engine, more fuel, bigger turbo charger, changes to the engine to take more turbo pressure, The only thing I think would increase mileage though, might be more turbo, and advance injection timing. I have not done testing yet on best fuel economy vs power I want going up hills.

future project... That big honkin cooling fan, Really want to convert that to one of the newer electric clutch jobs. Also in the future is moving power steering to an electric pump power steering, and link to speed, more speed = less pump pressure. Dont need power assist at 65 mph. Want all I can get in a parking lot.

side view cameras and itty bitty mirrors. -- that might change as time goes on. If I have problems with not being able to see well enough, or the police have a problem with my electronic mirrors.

Radial tires in stead of bias ply. -- Also running pressure of tires according to weight they carry, so much less than maximum pressure listed on the side wall. Tread pattern, those blocky treads pump more air, I have what would be called "shitty for the off road" tires. I could well see my self stuck on wet grass on a mild incline. But better highway mileage.

Six speed manual transmission -- mostly because less moving parts, usually mean less to go wrong. but, I like the gear spread and has .73 overdrive. First gear is low enough to get me moving from a stop on a hill. Dual disc clutch to take the extra torque the engine can put out if I am feeding all the fuel it can take.. extreme case around 700ft/lb to 800 ft/lbs estimated.

But with the way automatics are usually built, I think the manual will absorb less power operate.

with out the under tray stuff, fender liners, small mirrors, fan clutch, or electric steering pumps... This kind of bus gets 12 mpg all the time on the road. in town less..... but paying attention and such, when I get more miles on it, I expect to see 14 to 17 mpg at 65 miles an hour...... I think I might be able to get 18 to 19 when I call it "done".

This is a game for me. Something I devote my free time because it is fun for me to see how far I can take it.

1954 ford Wayne body, sitting on 2005 ford 450 chassis, cummins 5.9 12 valve engine, with NV 5600 six speed transmission, 3.73 rear end gears, steel rims, 245/70-R19.5 michelin hiway ribs. Steel wheels. Big job F700 front fenders. The front axle is as wide as the rear axle. The outer dimension of the tires is about 4" wider than the 1954 chassis. expected total weight with hooligans 12,000 lbs

william



Type of transmission and rear end oil .. synthetics ... much thinner viscosity wise = less drag.

I lucked out and got two very aerodynamic truck caps for $100 - pretty sure I can get rid of the brick-like school bus forehead making the bus more streamlined, look better, and have room for an overhead bunk

[cadillackid]

its MUCH easier to BUY the correct bus.. like others have said..

However that said, I have BUILT two busses thus far to be highway friendly.. the first one went from a 545 to a allison 1000 and so I gained 2 gears..



the second one I had a 545 that died and went tio a 643.. while technically i didnt gain any gearing ratio.. I did gain the lockup so now im able to not just run at the rev limiter all the time when cli,mbing the slightest of inclines.. my RPMs can be held steady.. that bus will top out at 68-69 at 2800 RPM.. (max safe RPM for a DTA360).. running at 62-63 I am at 2300 RPM.. I drove it one day so far on this trip at 65 running close to 2600 RPM and it really didnt mind... A/C blasting. and outside temp sunny, humid and 95 and I still never saw 200 on my temp gauge (or with a temp gun.. foot was only on the floor when climbing an incline.. otherwise i was backed off the throttle and cruising..

-Christopher


P.S. I used to be a big fan of the AT545.. but after Nuking 2 and running their counter-parts I will avoid them or plan on a build to get rid of it with anything but a classic bus.. (yeah im keeping the AT540 in my classic bus because its just what belongs in there.. and thats not a bus i plan to trek the rockies with... although i did it bringing it home)..
-Christopher

[Dirtdoctor]

I changed the tires to 11r22.5. A bit taller. But I’m fine at 60mph.

[Free Bird]

Originally Posted by jimburke77502

You have a bus. Taking any one of the inline 6's,(because let's face it, everyone has their own favorite) coupled to an Allison 545AT (with the future ability to upgrade to a 643), what's the 1st thing you do to make it more "highway" friendly? By that I mean getting better milage, not having the thing screaming like a porn queen in her best film yet, and keeping it with in the comfort zone of RPM's and a speed of no more than 65. I only say 65 because the old 55 is now 65. That and that's the most you want or need to push these things anyway. I'm curious to see what kind of responses I'll get.

OK, a lot of variables here, 2 biggest are size of bus and condition of transmission. CB and I both have short buses with 545, his is very high geared and works well, like it was a locker. I bumped mine from 430 to 410 gearing with marginal results, I now slip more (not concerned as am putting 5 spd manual in). If we were running full size buses the results would be more pronounced - more slippage.

Engines- I have a friend who installed an 8.3 in an older re bus where the 5.9 used to sit. He said that the bus didn't drive well after, suspension wasn't up to all that extra weight cantilevered way out behind the back axle. (maybe the frame wouldn't last either)

So my take is that if you are going to do just one thing maybe try replacing your transmission oil with Transynd?

I didn't bother as the 545 was never going to meet my needs. More than just better highway performance I want a nice low gear that will help me creep down steep logging roads without constant braking. Incidently I have driven a bus with the Allison 1000 series trans and it also lacked a low enough gear for descending steep bush roads.

[cadillackid]

the only automatic I know of wit ha creeper gear thats a mechanical is the allison 653, essentially a 5 speed 643 but first is a creeper..



once you get into the 700 series you get into SAE1 mounts which are a PITA on medium duty..



if I needed to creep, id do an allison 1000 and a 2 speed rear end..

[Ronnie]

Actually the MT-40 6 speed, 1st is a creeper gear at 5.29. Not real low but low for an automatic. Of course this trans is more commom in the old gassers of the 70's

[Free Bird]

Originally Posted by cadillackid

the only automatic I know of wit ha creeper gear thats a mechanical is the allison 653, essentially a 5 speed 643 but first is a creeper..



once you get into the 700 series you get into SAE1 mounts which are a PITA on medium duty..



if I needed to creep, id do an allison 1000 and a 2 speed rear end..

I prefer rock solid simple but even so I like your idea. A locking auto with a 2 spd rear or auxiliary would likely be a pleasure to drive. What the hey, lets add a jake and a visor- hmm air ride suspension and an a-ooggah air horn!

[jimburke77502]

Well I haven't checked the rear end yet, but getting it home yesterday in a 4+ hour drive, my 1991 37 foot BB with the cummins 5.9, allison 545, did quite well the entire trip. Taking mostly highway(other than a few small towns to go through) I averaged between 60-70 MPH with no sweat. Hell, there were people I was passing. And the motor didn't seem to mind at all. What probably held it back from doing any better was the fuel governing.

[sojourner]

Another option not mentioned is an auxiliary transmission. I recently purchased a Spicer 7231D which, when installed will give me a 2:1 underdrive, direct drive and .86:1 overdrive. My 4.78:1 gear ratio at .86 gives me 4.11:1 in overdrive. If I swap out the differential for a very commonly available 4.44 I'll get 3.82:1 in overdrive. This setup gives me a lot of options for different driving conditions without compromising.

[EastCoastCB]

Originally Posted by sojourner

Another option not mentioned is an auxiliary transmission. I recently purchased a Spicer 7231D which, when installed will give me a 2:1 underdrive, direct drive and .86:1 overdrive. My 4.78:1 gear ratio at .86 gives me 4.11:1 in overdrive. If I swap out the differential for a very commonly available 4.44 I'll get 3.82:1 in overdrive. This setup gives me a lot of options for different driving conditions without compromising.

That's groovy, Trav!

[Ronnie]

I have a spicer 5831B in my truck, same ratios as you mention. I think it is great and gives lots of gears available. However it is not syncronized so I have to really pay attention when shifting to get engine rpms just right for it to go in gear without grinding. Not so sure how it would shift behind an automatic.

Does the 7231 have syncronizers?

There are some neat videos of "twin stick" shifting on youtube.

[Sleddgracer]

Originally Posted by Ronnie

I have a spicer 5831B in my truck, same ratios as you mention. I think it is great and gives lots of gears available. However it is not syncronized so I have to really pay attention when shifting to get engine rpms just right for it to go in gear without grinding. Not so sure how it would shift behind an automatic.

Does the 7231 have syncronizers?

There are some neat videos of "twin stick" shifting on youtube.

53 years ago I drove an old at that time, B49 Mack - had 2 trans, a 5 and a 4 speed - the old gas pot had spent it's life doing short hauls between the saw mill and the railway siding where lumber was loaded into box cars - my job evolved into longer trips to service some mines ( 20 - 25 miles ) lots of steep hills with heavy loads - the 5 gear transmission was so loose it was sloppy and not always easy to find the gears - the 4 speed trans had barely ever been used and was still tight - trying to shift the two transmissions smoothly together was almost impossible because the 4 speed would slow or stop spinning while the 5 speed took for ever to slow down - I never was able to do an 'arm through the steering wheel two handed shift' of both transmissions at the same time - I had to resort to shifting one transmission, then the other, which didn't work great on the steep uphills, or gearing down on the descents - when I was loaded, it meant stopping completely to gear down before crawling down the hill - wasn't a pleasant truck to drive - tough old beast though

[Ronnie]

Originally Posted by Sleddgracer

53 years ago I drove an old at that time, B49 Mack - had 2 trans, a 5 and a 4 speed - the old gas pot had spent it's life doing short hauls between the saw mill and the railway siding where lumber was loaded into box cars - my job evolved into longer trips to service some mines ( 20 - 25 miles ) lots of steep hills with heavy loads - the 5 gear transmission was so loose it was sloppy and not always easy to find the gears - the 4 speed trans had barely ever been used and was still tight - trying to shift the two transmissions smoothly together was almost impossible because the 4 speed would slow or stop spinning while the 5 speed took for ever to slow down - I never was able to do an 'arm through the steering wheel two handed shift' of both transmissions at the same time - I had to resort to shifting one transmission, then the other, which didn't work great on the steep uphills, or gearing down on the descents - when I was loaded, it meant stopping completely to gear down before crawling down the hill - wasn't a pleasant truck to drive - tough old beast though

53 years ago I was a wee little kid....

[sojourner]

Originally Posted by Ronnie

I have a spicer 5831B in my truck, same ratios as you mention. I think it is great and gives lots of gears available. However it is not syncronized so I have to really pay attention when shifting to get engine rpms just right for it to go in gear without grinding. Not so sure how it would shift behind an automatic.

Does the 7231 have syncronizers?

There are some neat videos of "twin stick" shifting on youtube.

The 7231 is not synchronized either. There's a video of a guy who did install one on his skoolie with an automatic trans on youtube.

https://www.youtube.com/watch?v=WwkRAwIpDs8

There's a learning curve to any non-syncro combination. I pretty much plan on shifting into the range I want while stopped anyhow since I really don't see the need to split gears and shift on the fly like one would hauling a heavy load.

[sojourner]

Originally Posted by Sleddgracer

53 years ago I drove an old at that time, B49 Mack - had 2 trans, a 5 and a 4 speed - the old gas pot had spent it's life doing short hauls between the saw mill and the railway siding where lumber was loaded into box cars - my job evolved into longer trips to service some mines ( 20 - 25 miles ) lots of steep hills with heavy loads - the 5 gear transmission was so loose it was sloppy and not always easy to find the gears - the 4 speed trans had barely ever been used and was still tight - trying to shift the two transmissions smoothly together was almost impossible because the 4 speed would slow or stop spinning while the 5 speed took for ever to slow down - I never was able to do an 'arm through the steering wheel two handed shift' of both transmissions at the same time - I had to resort to shifting one transmission, then the other, which didn't work great on the steep uphills, or gearing down on the descents - when I was loaded, it meant stopping completely to gear down before crawling down the hill - wasn't a pleasant truck to drive - tough old beast though

Ah, the infamous B model Mack. My dad drove them back in the day and would tell stories of the "joy" they were to drive. I got the impression it was somewhat akin to flying a helicopter since it pretty much maxed out the use of all appendages LOL!!
Sounds like your main gearbox needed to get re-shimmed (they have a small bit of preload on the shafts).