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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: kyle4501 on July 09, 2008, 10:15:18 AM
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With fuel costs consuming more of the travel budget, I'm re-thinking my hot rod attitude of the BIG ENGINE to the top of the mountain in high gear attitude. :o
So, if I'm gonna stick with a lower HP engine to minimize fuel useage, I'm gonna be leading more parades up the hills & mountains. ;D
I'm OK with that, but I think I might like having more gear ratios to choose from while going up those mountains. Having lower gear ratios in the campgrounds wouldn't be all bad either. 8)
Now the question/ request:
For those that have installed transmissions with more gears to chose from, could you share in this thread what you learned? (I've searched & can't find much)
Links to other threads are good too. ;D
Bus year & make and the engine/ transmission installed PLUS what other changes were required (bulkhead modifications & etc).
A critique of the process, effort required & end results (road test) would help others decide what best fits their needs.
THANKS!
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Kyle,
Physics says that to go up a hill faster takes more energy. So faster means less MPG. That is an immutable law. While other factors come into play those statements are always accompanied with "all other things being held constant".
A man I deeply respected once told me that the max efficiency of a gas engine was found at wide open throttle. I recently pondered that and I guess a diesel is running at WOT by design. Still, I think a smaller engine gets better MPG. The funny thing, to me, is that a smaller engine and a larger one should have the same fuel flow to maintain the same speed as long as the speed was low enuf for the small one to achieve. It doesn't seem to work that way though and I don't think a heavy foot is all the answer.
A Knut with a new newly installed Cummins M11 is getting 12 MPG with the norm being 10 plus. Another with an ISM is getting high 8 but that will be 9 plus in time. Road ranger 10 speed seems to be the ticket regardless of the engine as "Bob of the north" gets 8 plus with a 500hp 8V92 and a nine speed manual (go figure). Now Bob is nothing short of delighted with his Prevost bus and well he should be. Most of the 8V92's are getting 6 or 7 with some getting 3(brrrr).
None of this is my personal experience but i have talked with many on the subject. What i am saying I guess is that these are not my own persoonal lies....I'm just repeating them ;D
Hope this helps,
John
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The statement "faster means less MPG" assumes the efficiency of the engine is constant regardless of RPM.
Most engines have an efficiency curve, hence the desire for more gears to allow one to operate the engine at it's most efficient RPM. As a result, better fuel economy can be observed & probably, more fun driving it.
I didn't mean to imply I still wanted to be the fastest up the hill. I meant top say I was OK with going slower & that I wanted more gears to do it with.
Also, a tranny swap may be more cost effective than a total repower.
4 speeds may have been enough for greyhound, but I ain't greyhound & I don't park at bus depots. ;)
Several friends have mentioned more gears & I just thought a thread discussing the pros & cons of different setups would be easier for those researching the possibilities.
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Kyle - I assumed at first you were wanting more gears to enable a smaller engine to get up the hills; now I'm not sure if that was what you meant, so the following comments about fitting smaller engines may be irrelevant, but I've already typed it so will post it anyway:
Obviously some engines can produce a given amount of power more efficiently than others, due to design & technology differences - but, leaving those differences aside, the same vehicle fitted with a smaller engine won't use any less fuel unless the driver uses less engine power - which of course he might have no choice about if the power isn't available.
A good way to convince yourself of this is to look at the sales brochures of any car range - for example, if you look at the specs of a Ford Fiesta fitted with the various different engine options you will see that the economy figures are broadly speaking very similar irrespective of engine capacity. Then look at the Ford Focus and Mondeo models (ie. progressively larger vehicles) fitted with exactly the same engines you will see that the economy drops as the weight and size of the vehicle increases, but still remains broadly similar across the range of engines.
Obviously, when producing the economy figures for the various Fords each car was driven in a very efficient and economical manner, which is probably quite different to the way they are driven in real life when it is only natural to make use of the power that is available. Nevertheless, if unless you are switching to a much more modern and fuel-efficient design of engine I'm not sure reducing engine capacity for the sake of it makes much sense.
Jeremy
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From my driving for the last 30 something years. I have seen many trucks on the road with the Small engines and multi shift tranys that you could out work a bigger engines with if you knew how to use the choice of gears to your advantage.
I know that the old Pete I drove had a 400 cumins in it with a 5x4 transmission and 4.33 rears was a bear in town but when loaded it would do the work of a bigger engine. The more gears the easier it is to keep it in the choice RPM area.
I don't think you would want a two stick in a bus but a 8 or 10 speed might not be too bad.
Myst my worthless thoughts.
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Thanks Bob, That is what I was trying to say - more gears let a small engine work more efficiently ;D
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Here's my experience... for the situations I've encountered, it just doesn't matter.
I bought my Crown and with it came with it's 220hp engine and the factory 4 speed. I got 10mpg and it took 6% grades between 30 and 35mph. But my top speed was 61mph due to the crappy rear end gearing.
I then changed the tranny to a Fuller 9 speed with overdrive and other than the fact that virtually nobody could figure out how to shift it but me, it still got 10mpg and still went up those same grades at the same speeds. Top speed was now around 78. Cool!!
I got tired of shifting the 9 speed grinder (because I was now the only driver on long trips), so I put in a nice shiny Eaton fully synchronized 6 speed. At the same time I changed my rear axle to accomodate a Telma retarder, and the rear end ratio changed from 5:29 to 4:11. It was perfect, still went up the grades at the same speeds and got 10mpg, but being that the tranny was not overdrive and the rear was still a bit high, my top speed reduced to 69 which I didn't like.
So last but not least I found an Eaton FSO8406A which is the fully synchronized 6 speed with overdrive, all the other ratios are different than they were in the non-overdrive Eaton, and now my top end is back around 78 or so, and guess what... still the same speeds on the same grades and 10mpg.
So while I originally thought from all I'd read that having all those gear choices made a big difference, at least for this bus it didn't make ANY difference.
I absolutely LOVE the 6 speed overdrive, ANYONE can now drive the bus, mileage is the same, time-to-destination is the same, etc.
My 2รง worth...
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I do not know if a RTO 910 will fit in your 4501, but if it will, then that is the 10-speed Roadranger you want. Also do not know what kind of mill you have, however the RTO-910 has very close gears and was practically designed for the 318 8V71N.
About the only other thing I can think of is that the Fuller RT/RTO/RTOO 910/1150 series of Roadrangers are now kinda very old and may or may not be easily available at your local, friendly heavy truck wrecking yard. Most may have been recycled.
However, if you can find one, expect to pay about $1000 bucks (US) for a good runner complete and about $1500 to $2000 for a rebuilt unit complete with warrantee. A good core for rebuilding yourself can be had for only a few hundred bucks or soosss.
Why a RTO-910? Well, for those who like to know this kind of stuff, the gear sets are...about... 1st, 6.27, 2nd, 4,98, 3,95, 3.13, 2.57, 2.00, 1.59, 1.26, 1.00 and .82. Yeah, very close together indeed. Perfect for a somewhat underpowered Bus Conversion.
My old Crown Super Coach had this particular transmission. Perfect starting from stop up one of those steep, endless, Western grades of 6% or 7%. More like shifting a dirt bike than a heavy truck tranny. About 2" of shifter movement and 5# of effort.
In my humble opinion, you may want to stay away from the more modern and available 9-speed Roadrangers. They have kinda wide, low gears that would be wasted in a light weight Bus Conversions. This type of tranny is designed for heavy hauling.
Anyway, I usually started in 2nd and progressivlely shifted up and before I knew it, the old Crown was at cruising speed. Very easy to keep the rpm between 1700 and 2100. At 55 mph, I had a choice of 3 gears, 8th, 9th, and 10th. Very cool. Good luck. :) :) :)
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HB hits the nail on the head:
You want a tranny with overlap and choices at the top, for hill climbing.
It doesn't do any good to fit a new transmission that still has to wait for the speed to drop to 50 mph for the first down shift as the hills rise ahead of you.
no one suggesting a 13 speed? An Eaton Ultrashift 13, no clutch pedal, would be fun to pair up with the right differential...
happy coaching!
buswarrior
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Now we're getting somewhere.
It seems to me the overlap would make selecting the right gear so much easier.
I also like the Ultrashift idea, but I need more info ;D
I believe my 4501 can handle any transmission if the bulkhead has the necessary preparation. It also has a 3.70 ratio axle.
Thanks ! ! !
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Kyle -
OMG - you're going to. . . going to. . . going to. . . going to cobble up the powertrain on the hallowed Scenicruiser?
Is there no justice left in this world?
;D :D ;D :D ;D :D ;D
On a more serious note:
IBME, after 25+ years in the bus industry, is that the weight of the coach, the aerodynamics of the coach, slushbox or stick shift, and the weight of the operator's right shoe are the three major components of good (for a bus) fuel mileage. Just like cars, sticks get slightly better mileage, but as efficient as the newer automatics are, it sometimes becomes a moot point.
Weight is the killer - takes HP to get rolling and keep it rolling. "Build the interior out of balsa wood, not oak & granite" type of thinking, if you will.
I loved playing with all those gears in the 10-speed RoadRanger-equipped Crown skoolies. . . but also often got tired of going thru seven gears just to get to 35 mph. 90% of the time I drove them like 5-speeds by skip-shifting, as did most of the other drivers in the district.
And they still went up the 6% grades at 35 mph. . . :D
With the MCIs in the fleet I worked at, the sweetest, IMHO, powertrains were in the 9s that had the 8V71Ts bolted up to HT-754 five-speed Allisons. Tuned to just 350 hp, with the stock 3.73 rear axle, they would often get 7 - 7.5 mpg when the 8V71 and 6V92TA coaches were getting 5.5 - 6.5 on the same runs.
One thing to keep in mind, if you go to almost any of the mechanical multi-speed RoadRangers or similar, is the shift pattern. Unless you do some clever engineering, you'll end up with a backwards shift pattern, since the transmission is "turned around" in a pusher configuration compared to a truck installation. (Shift it "normally" and you'll have 10 speeds in reverse!)
IMHO, if you're going to follow thru with this project, I'd suggest you try to find a truck with an Cummins ISM coupled to an UltraShift (or a Series 60/UltraShift) that's been wrecked, and buy the whole truck. That way you can get all the wiring harnesses and other the other goodies needed.
TomC should be able to help too, as he sells Class 8 rigs and deals with powertrain configurations daily. Tom - where are you??
OTOH. . . you could leave it stock - how many millions of miles did they run that way??? ;D
FWIW & HTH. . .
;)
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Isn't the Ultrashift completely computer controlled? I know the Autoshift can be linked to a machanical engine with an interface, but no idea if the Ultrashift has this option.
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Kyle, knowing that you're A) an Engineer and B) a bloomin' nutcase perfectionist, I'm going to throw my $0.02 in here and ask you to spend some time with your Engine/Transmission package before you go off chasing butterflies.
I've been pushing this MC5A with the DD8V71 / 4 speed Spicer package up and down the roads for over 2 years now and have come to this conclusion:
Between the Engineers at MCI and the Bean Counters at Greyhound (and others) someone definitely had their act together. For that era, remember the choices of engines and trannies we have now didn't exist then, this was the best package available....and in my opinion still is. I'm not the first one up the mountain (on those rare occasions I tackle them...and we LIVE IN the mountains) and I'm the last one down, even with Jakes. But when I consider the cost and labor in attempting to improve what I have...re: Boogiethecat, as against what I hope to achieve I believe I'd be shoveling $hit against the tide.
Sure, I'd like a slower reverse gear...but can live with what I have rather than re-engineer the whole package.
I have some miserable places I have to stick this ol' bus and do it quite well considering my experience (or lack thereof) and power options.
FWIW
Bob
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The only thing changing from a 4 spd to a 9 or 10 spd will get is a lot more shifting and maybe 3-5 more mph on the hills-sometimes it will be the same if the torque/speed matches the same gear in either trans choice.
My advice-forget the trans swap. If you want maximum change in both fuel economy and performance, turbocharge and air to air aftercool your 8V-71. I did and I can tell you from experience, that the performance difference is quite noticeable. Granted I increased my power also, but you could keep the 65 injectors for a fuel efficient 8V-71. You would probably see 2-3 more mpg and better hill climbing. With the low mileage that most of us drive our buses, turbocharging rather than engine swap is much more cost effective.
But with the room of the 4501, a Cummins ISM with a 9 spd (I like the shift pattern of the 9 better than the 10), would be ideal. Good Luck, TomC
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My two cents worth..... (and this is with the caveat that I've only put in 3.5 million miles of driving truck, mostly heavy haul in a 30 year time frame).
Even though I am a hard core, tried and true, true blue, through and through, GMC - Detroit Diesel Afficianado, I detest the high gearing on the lower gears of the coaches, whether it's GMC, MCI, Flxible, TMC, Eagle, Prevost or any other manual shift transmission. The buses were built to go from stop to stop and terminal to terminal. Once in awhile, they would see a shop, but not nearly as often as they really should have.
My choice, if I were going to keep the Scenic all mechanical and stay away from the computer controlled doodads, would be a nice "Shiny 290" or 335 Cummins hooked to a RTOO 9513 Road Ranger. If I wanted HP, I'd stick a NTC 400 BCIV Cummins with a RTOO 14613 Road Ranger.
Either one I would couple to a Mack 4.38 or 4.56 rear end. Driveability would be excellent, the rpm range with 20" or 22.5" rubber would be in the sweet spot for climbing and also for getting into tight uphill reverse situations.
There is no law in the world that says you have to shift through every gear, in fact, most of the companies I ever worked for would consider you to be abusing equipment and wasting fuel if you did. All those gears are there to allow you to choose the very best combination of power, RPM and driveability to move the load with decent return on the parts.
NCBOb said:
I've been pushing this MC5A with the DD8V71 / 4 speed Spicer package up and down the roads for over 2 years now and have come to this conclusion:
Between the Engineers at MCI and the Bean Counters at Greyhound (and others) someone definitely had their act together. For that era, remember the choices of engines and trannies we have now didn't exist then, this was the best package available....and in my opinion still is. I'm not the first one up the mountain (on those rare occasions I tackle them...and we LIVE IN the mountains) and I'm the last one down, even with Jakes. But when I consider the cost and labor in attempting to improve what I have...re: Boogiethecat, as against what I hope to achieve I believe I'd be shoveling $hit against the tide.
FWIW
Bob
I have to respectfully disagree. These buses were built to move at a decent clip up hill and down, not to be backing and filling up an incline from a dead throttle start. Terminals and stops and shops were never on an incline. Remember the debacle of my trying to climb the hill into your campground when the idjit decided he was gonna come down after I had already started up? I not only ran out of power, but I was burning the clutch trying to make my 26K lb. bus move.
The engineers were working with the parameters that Greyhound, Trailways and a multitude of other companies gave them.
The spicer transmissions were one of the cheapest to build and at the time the MC5 was built, a clutch could be changed for less than $300 parts and labor included.
The whole idea behind the way these buses were set up was to be cheap and reliable and quick to fix to get back on the road. Trucks are somewhat different.. with a truck you never know what kind of load you'll be carrying, 8,ooo pounds or 48,oooo pounds. With a bus, it's a bit different, the companies knew they would not be hauling more than 35, 37, 41, 43, 45, 47, etc. passengers and a bit of freight and luggage. Even the vaunted claim of 4 - 8V71's in the bays of the Scenic would only be 10,000 pounds, with 45 passengers @ 160 lbs each, only adds another 7200 lbs. Add to that the luggage, you still end up with less than about 20,000 lbs. of load. On the runs these buses were put on, their gross weight really had no bearing on the driveability of the bus. Our actual use is much more demanding for these coaches than the intent and purposes ever thought of by the hound or TW.
Just one more item here... I've not seen it mentioned in any thread or post on any board... Progressive Shifting
To gain maximum fuel mileage, the idea is to shift as soon as the engine will pull it without lugging. That means that you don't need to go to the top of your governor if you are starting out on a downhill slant, or even if the road is level. As you go up in the gears, it will take more RPM's to get to the next gear, hence the "progressive" part.
I've been asked how I can achieve 13mpg with my PD4103 and my answer is always, "Shift Progressively". No need to make the engine catch up to the speed of the wheels if it's on a no load start. I shift up through my gears as quickly as possible. For instance, if the speed limit is 35 mph, I know that my transmission is geared so that I will be in 3rd gear at about 1800RPM, but, if the terrain is flat or slightly downhill, I go ahead and shift into 4th since there is no real load on the engine and I can drop back to 1100 RPM. As soon as I see a hill coming up, I can shift back down to 3rd, which puts my transmission back into the power range of 1600 to 1800 RPM. No need to wait until I've started climbing, I try to always look ahead at least a half mile and usually on open road one or two miles.
'Nuff Said.
Dallas
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I already get ~10 mpg in the last bus on the trip up from lower Florida. The 4501 I drove down from Delaware got ~9 mpg & it has low compression on 2 cylinders. The speed was ~65 mph. The motor didn't seem to like going any slower & would loose LOTS of speed on hills. Any faster & she got thirstyer!
My fuel mileage concerns is what led me to forgo the re-power to higher HP. A 'normalizing' or 'smoke' turbo might be considered, but only to maintain reasonable power in higher elevations.
My actual time behind the wheel is what is leading me towards more gears. Stop & go traffic really stinks with the stock gearing. The 9+ speeds will give me more choices. & like Dallas said, I'm using my bus differently than Greyhound did.
More than one of my 4501s needs a transmission anyway. And for those that don't know, the 4501 takes a special trans & If I have to make something work . . . I may as well look into other options. besides, some of these have already been raped pretty badly before I got them, so anything I do will be an improvement.
The manual transmissions that shift for themselves & don't have a clutch pedal sound nice to old knees that aren't what they used to be.
I'm not the kind of person who will follow what everyone else wants to do simply because that's what they are doing.
I want to know details of the actual swap & what is involved. I can then decide for myself what path I'll take.
Hell, if I had listened to the masses, I wouldn't have bought 8 4501s! I did sell 2 of them tho . . . :'( seems when I get to 7, I run into more problems. . . . .
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You're right about the smoke turbo... that was the one probably MOST important change I made to my bus as far as grades go. Prior to that there were a number of black-belching 5mph-in-first grades that I'd take every year. The turbo (set with a wastegate at 5psi) instantly turned those into 30mph no-smoke grades, regardless of what tranny I had. If you're going to spend money to get up grades faster, do the turbo first. NO tranny will help at altitudes!!!
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"I'm not the kind of person who will follow what everyone else wants to do simply because that's what they are doing."
Isn't that kind of the definition of a Busnut? If we followed the rest of the crowd we would all be herding a S&S down the road. More power, err make that gears to you. ;D
Don 4107
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This thread was intended to have details of what is required & involved with doing the tranny swap.
Personal preferences will dictate what each owner does with their bus.
For example, I could have chosen a new bus shell with the latest power plant. . . But I chose a 50+ year old derelict relic ;D
If I was using logical thought processes, I most certainly wouldn't be converting an old bus! . . . . :o
boogiethecat,
True, but more selections can help at low speeds, for gradeability, & my mental satisfaction while driving ;D :o
Don 4107,
You said it!
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Personally- and this from one who drove 21 years with nothing but 13 speeds-there's nothing equal to the pleasure of driving a bus with an Allison. The off the line acceleration and ease of operation more than makes up for the loss of 1-2mpg in fuel mileage. If I had the 4501, I would put in a HT740 and be done with it. Good Luck, TomC
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Hey Kyle, you may be right... but for me getting RID of that 9 speed was the best thing I've done to the bus since the Turbo. I absolutely do NOT miss all those gears, slow speeds or not. Not not not.
And Tom, yes yes yes. My Bluebird has an allison and I LOVE it. If I could stick one in the Crown I just might. But alas no overdrive. Oh well I'm happy with the 6 speed.
Amazing how each of us has their favorite combo of things when others of us hate the same things. That's what it's all about!!
G
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You could change the rear end ratio again to accomodate the HT740. But with the big oil pan that sticks down making ground clearance a problem, at least with your Crown, the 6 spd is probably the best. Good Luck, TomC
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All good answers; we are so lucky to have the options open for us to use in the pursuit of our unusual hobby of Bus Conversions. I think the clutchless "ultrashift" trannies need a computer controlled mill also, as well as the computerized transmission. Also, aren't the clutchless models of the modern type, with rather wide gears, expressedly designed for heavy 18 wheeler hauling and with/for the "modern" high torque, low rpm 4 stroke diesels?
If you could get such a transmission to fix into your 4501 and get it to talk to and work with the mill, you still might be faced with gear ratios not exactly to your liking. Lots of low gears you would never use, except for creeping and backing. Anyway, it may be moot since you may want to keep the existing mill you have, which, if I could guess, is a 8V71N or something very close.
Which brings us back around full circle. You want more gears. You want to keep the existing mill you have right now. I loved my RTO-910. However, like others have already said, maybe an Allision may be the way to go. Yeah, once you get spoiled with an automatic, you will not want to go back to the stick, unless you are like me and kinda crazy and just like to shift for yourself.
Allisions are very quick off the line. All you have to do is slowly floor the pedal and everything else is done for you. Very cool. My Roadranger was toad dead slow getting from 0 to 30. People passed me all the time. But, then again I was having fun playing heavy truck driver, PROGRESSIVELY SHIFTING and using every gear. When I got tired, yeah, like others said, I just shift her 2, 4, 6, 8 then 9th.
About the only other thing is that Roadrangers are kinda wide, flat and long. I do not know if it would fit into your 4501. U-joint needs and stuff like that. They are also heavy; mine was about 650 pounds or sooss. Some sort of shifter rod assembly will be needed. My Crown had one (1) shift rod with about 50 grease zerts and carrier bearings. You may need to figure out some way to reverse the shifter soos you will not have a backyards shift pattern. Good luck and my two cents worth...again. :) :) :)
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Hi RJ,
Take some time to think about it and then please explain your statement, (Shift it "normally" and you'll have 10 speeds in reverse!). Take some time to THINK about it.
Thanks, Sam 4106
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I used to want an Allison, but when I asked about that swap, I was preached to about the fuel mileage penalty & told to stick with a manual trans. :o
(I also got some good info concerning what was involved.)
So, now I ask for details concerning what is involved in making the swap to a 9+ speed manual & I get mostly advice to do something else. ::)
I want the details of what is involved with the 9+ speed swap & how they were dealt with. THEN I can make an informed decision on which way to go.
Thanks to those who have provided usefull answers. ;D
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Hi folks. Lots of good input.
As most of you know, I have a Series 60 with 10 speed AutoShift in my Eagle. I went to the AutoShift, since I had to have an overdrive when I went from two stroke to four stroke. I could not afford the Allison World tranny.
My acceleration is significantly slower than an auto -- not because of the shifting, but because I have to build boost with each gear change.
I love having all of the gears when descending a large grade because I can make the Jakes do all the work and keep them in the right rpm range.
Now to the AutoShift for mechanical engines. If the AutoShift does not see the computer input from the engine (J1939 signal), it becomes an AutoSelect. In this mode, you start with the clutch and then you accomplish the shifting by breaking the torque with a slight throttle reduction, then adjust the engine speed for the next gear. When the RPM is correct the transmission will drop into that gear. The transmission has a small monitor that shows the gear selected and which way the engine speed has to be adjusted. I have not driven mine in that mode, but I would guess that a person would quickly learn how to drive the bus with minimal issues.
In either mode, you can skip gears if you wish (I generally do not).
You would still need to fabricate the wire loom (five wires plus one shielded twisted pair, as I recall).
The AutoSelect with a mechanical engine would let you eliminate the need for shifting rods and lots of clutch work.
The last I checked, the junk yard price has been going up. I think I got mine for less than 3K (was an engine/trans combo purchase but they were separate). Last I heard, they are at least twice that.
Jim
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Kyle, I am in the process of changing 4 to 10, one of the main problems is to use the 2 shift rods to shift the 10 speed. The way to take care of this is attain a trans cover and shift tower from a Eagle cable shift setup then use the rods in place of the cables. A 1" spacer will be required, I finished mine yesterday, alot of cutting with a jigsaw use lots of WD40. Other problems is flywheel and clutch cange from a single plate to a double pull type.
Another problem with a Eagle is the need to do some frame modification, on your cruser you probably won't need to do that, Greg Bush
installed a 3408 Cat with a 13 or 15 speed in his SC so there must be plenty of room
Good luck with your project, I will be glad to share my experiance. Bob Gilgert 05 Eagle.
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Hi RJ,
Take some time to think about it and then please explain your statement, (Shift it "normally" and you'll have 10 speeds in reverse!). Take some time to THINK about it.
Thanks, Sam 4106
Sam -
Good catch. . . I must have been asleep at the wheel when I made that comment.
I should have said if you shift it "normally", you'll be starting out in 10th instead of first.
The 10-speeds in reverse would pertain if you put a RH engine in a LH V-drive, or vice versa - a LH engine in a RH T-drive (like the Scenics).
Kyle -
Sorry if I hijacked your thread a little. . .
FWIW & HTH. . .
;)
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Hi Kyle,
Can't really provide any mpg info, but i repowered my Scenicrusier with a 8V92TA mechanical and a Allison HT754. I left the original rear axle ratio in place. I understand it should be 3.70 to 1. I really didn't get too many miles on her with this repower before i blocked it level and did some major rework to the upper deck (lowered the floor). But it sure did take off from a standing start and would get up to speed rathur nicely. I did explode one of the u-joint yokes, was a new driveshaft and i managed to pick up all the parts and discovered a hairline crack in the yoke. Driveshaft and yokes were replaced at no cost and drove it home about 2 weeks later. There was some fab work required for the drivetrain, motor mounts and radiator mounts for the new radiator. Had a new radiator build which was about 40% larger than the original. There was a small amount of clearence work required to get the Allison in, but not much. Hope some of this helps.
Mike
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Mike, I'd like to see your setup one of these days. ;D
RJ, I always appreciate your insight & I don't mind a little hijacking . . . . :o
I was just trying to do a better job of explaining my question/ request ;D
Bob, Now that is something I could use a few pictures of. 8)
Jim, the AutoSelect is definitely in line with what I want. That sounds promising. I think I could even talk Nancy into driving :o ;D 8)
Please keep the ideas coming!!!
I know I'm not the only one who is taking notes here ;D
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Kyle, have you thought about maybe putting two 4-71s in there with some kind of fluid coupling between them. You could run just one in town and run them both when you are on the big road. ;) Seems like some other folks worked on this problem 50 years ago. :D
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Charles -
Now THAT's funny!!
;D ;D