| Author | Message | ||
| Rick Lohrey (Rlohrey)
Registered Member Username: Rlohrey Post Number: 1 Registered: 9-2011 Posted From: 148.66.112.246 Rating: N/A |
New to this forum, it's nice. I'm looking to buy a bus for rv conversion. Which is the best drive train? Whether front engine, or pusher, there are quite a few types, which ones perform and last the best? Most importantly: which ones to avoid? Things such as 'cavitation' can ruin one's day. Flat interstates and through the Rockies would be typical, plus is 70mph too much to ask for in a bus?(not in the Rockies!) Appreciate all help! | ||
| Laryn Christley (Barn_owl)
Registered Member Username: Barn_owl Post Number: 719 Registered: 10-2006 Posted From: 108.15.217.54  Rating: |
Welcome to the board. If you are doing one from the ground up then you want a good solid shell. The cost and time spent doing a conversion is the same if you do a old one or a new one, but the value in the end will be very different. Would help if you could give us some more information about what you want to do and what is your budget. A completed conversion is a better value and you can use it right away. | ||
| John & Barb Tesser (Bigrigger)
Registered Member Username: Bigrigger Post Number: 552 Registered: 9-2007 Posted From: 96.42.5.35  Rating: N/A |
Welcome aboard Rick. With the economy being what it is today there are a lot of previously owned conversion buses available for "pennies on the dollar". On this board you will find most advice leans toward rear engine diesel as most front engine RVs are refered to as S & S a derogatory term that stands for "sticks and staples" or factory built RV's usually on a truck style chassis. Most of the older stuff will have 2-cycle Detroit Diesel motors in various sizes and as you move into more modern engines they are usually electronically controlled. The newer ones generally run more economically but there are some of us who prefer to keep the old ones going and they don't require a lot of sophisticated equipment or knowledge to keep them running. Good luck on your journey, remember "getting there is half the fun". John | ||
| Tom Caffrey (Pvcces)
Registered Member Username: Pvcces Post Number: 1384 Registered: 5-2001 Posted From: 65.74.68.2 Rating: |
Hi, Rick. If you would say what you mean by "best", we could probably offer some constructive advice. Otherwise, it looks as though the best of everything to consider will be found in one kind of bus. Figuring out what you are trying to accomplish will let you zero in on what is possible. If fuel economy is very important, the lighter coaches such as GM and Flxible will be able to give you good mileage. If room is what you want, they are available up to 8 1/2 feet wide by 45 feet long. In some makes, an automatic transmission comes with a serious mileage penalty. Aluminum coaches may be able to lower the maintenance costs, depending on whether the lack of a metal shine is important to you. If you are honest with yourself, it may save you a lot of money and strain over the long term. For what it's worth. Good luck. Tom Caffrey | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 1585 Registered: 10-2006 Posted From: 75.58.183.66  Rating: |
The costs of repairing the "more modern" engines can eat any fuel savings in a heart beat. An older camper selected for fuel economy will frequently do over 9mpg/70mph , with a stick shift, not in the mountains. Even if you got 12 on a "modern" engine it would take more miles than most bus campers see in 20 years to pay for a set of injectors that cost $5000. Figure out your Desirements , your intended lifestyle. Boondock, weeks or months on end with a toad as supply vehicle, tour the UDA seeing the sights,Snow Bird Sitting in a fine park for the winter? All are valid lifestyles , but each camper would probably be set up very different in terms of outfitting. "Make a List , Check it Twice , isn't just for Santa. Interior building is not a couple of weeks job , its a hobby in its self. FF | ||
| Tom Christman (Tchristman)
Registered Member Username: Tchristman Post Number: 329 Registered: 1-2006 Posted From: 66.218.33.156 Rating: |
Unless you know engines, I would stay away from the 2 stroke Detroits. Finding mechanics to work on them is getting few and a far in between. A mechanically controlled 4 stroke Diesel will be the most reliable. Some of those engines will be Cummins NTC & L10, Caterpillar 3306 & 3406. They won't get quite as good fuel mileage (but much better then the 2 strokers), but will be much easier to work on and repair. Electronic 4 stroke engines will get the best fuel mileage-but have an electronic break down, and those fuel mileage savings go down the drain. The "small block" engines that are easier to install to look for would be Cummins L10/M11/ISM (all the same block), Caterpillar 3176, C10/11/12/13, Mercedes 4000. Big block engines that are typically 1 million miles engines are Caterpillar 3406E/C15/C16 (same block); Cummins N14, ISX; Detroit Series 60. If I were doing an engine swap, I'd use the Cummins M11-pre 2002 EGR and have rebuilt to 500hp RV specs. Good Luck, TomC | ||
| Tom Christman (Tchristman)
Registered Member Username: Tchristman Post Number: 330 Registered: 1-2006 Posted From: 66.218.33.156 Rating: |
As far as tranny goes-you'll get the best fuel mileage with a multi speed transmission-at least 7spd-so to have both low enough gears for startability and an overdrive for cruising. Remember-most on road buses were used terminal to terminal-so just a 4spd worked sufficiently for their use. A 4 spd can be difficult to use-especially trying to back up hill into a campsite, or starting on a steep hill. After 1.3 million miles of over the road truck driving-driving only 13spd Roadrangers (which I still believe is the best over the road transmission), I would have nothing but an Allison automatic-even with the fuel mileage hit. Typically you'll loose 1-2mpg with an Allison over the manual transmission. But the driveability, startability, maneuverability, is second to none. Good Luck, TomC | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 1586 Registered: 10-2006 Posted From: 75.58.183.66 Rating: |
Most every slushpump has a loose (unlocked) torque converter at start.an extra 2.5 multiple (or so) gearing in first or rev. So being in any campground will not be a problem with startability , fwd or reverse. Otherwise it would be empty of everything but trail bikes and bull dozers. Most bus campers are quire light 1/3 to 1/2 what a truck would be so 4 - 5 speeds is grand, esp if it is shifting itself. Starting 80,000 lbs on a 12% hill is required for some trucks , not on many coaches. FF | ||
| Rick Lohrey (Rlohrey)
Registered Member Username: Rlohrey Post Number: 2 Registered: 9-2011 Posted From: 148.66.112.246 Rating: N/A |
Okay. Thanks for the good info. I'm currently looking at a 68 GMC with a 6v92/manual 4speed(I know that's not stock). Will an automatic trans fit this application/bus? If so,which ones and are there any to avoid? I figure to spend up to a month at a time on the road, two/three times a year. From NE Texas to each corner of the U.S. using Interstate highways say, in the southwest,or mid-country. I mean, how many hours does it take to see desert, or wheat fields? State highways are for 'cruising' the rest of the time. The Rockies, yes slow down and enjoy the changing view, same as any mountain, or coastal regions. Coastal roads sound nice. Dependability, lower cost of maint. (non-electronic seems to be avoided) and longevity are compromises with many options available. I've found 'simpler is better' to usually hold true in most cases. Sorry for being too general before. I'm trying to learn as much as I can understand before investing. I welcome all responses and hope to not irritate too many in my research. Thanks to all for sharing. Rick | ||
| Rick Lohrey (Rlohrey)
Registered Member Username: Rlohrey Post Number: 3 Registered: 9-2011 Posted From: 148.66.112.246 Rating: N/A |
Sorry, I'm still being too general. The GMC I'm considering is,best I can tell is a 4503(fishbowl?) and may be a 'suburban' coach. It's had a partial coversion, but doesn't seem to have had 'standing pass. windows'. Thanks, again, Rick | ||
| joe padberg (Joemc7ab)
Registered Member Username: Joemc7ab Post Number: 551 Registered: 6-2004 Posted From: 66.38.159.33 Rating: N/A |
Rick If it is a Suburban, tthe passengers would have been sitting mostly. The v730 automatic I believe will bolt in place and would be the only choice available. There are many GMC nuts here, and I am sure some will chime in and elaborate further. Joe. | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 543 Registered: 3-2006 Posted From: 216.198.139.38  Rating: N/A |
Joe You are right. The V730 will bolt in with the use of a spacer ring which is the hardest part to get these days. They are getting scarce. Bill | ||
| joe padberg (Joemc7ab)
Registered Member Username: Joemc7ab Post Number: 552 Registered: 6-2004 Posted From: 66.38.159.33 Rating: N/A |
Bill Would the regular 6v71/730 transit layout have a spacer ring in place?. If so,a friend of mine send that to the scrapper last month. I saved the starter and transmission filter, but may be should have looked closer before it went. | ||
| Bill Gerrie (Bill_gerrie)
Registered Member Username: Bill_gerrie Post Number: 545 Registered: 3-2006 Posted From: 216.198.139.38 Rating: N/A |
Joe When I worked for Toronto Transit we ran 6V71 in a GMC and they didn't require the spacer ring for the V730. I now run a 6V92 in the same bus and it requires a spacer ring. Transmission won't clear the rear engine mount without it. If you cut away a little metal you could probably get it to clear as it almost makes it. Just thinking out loud. Bill | ||
| Laryn Christley (Barn_owl)
Registered Member Username: Barn_owl Post Number: 723 Registered: 10-2006 Posted From: 108.15.213.71 Rating: N/A |
The v730 is a very tough tranny that is more than adequate for bus conversions. They are plentiful, inexpensive and were built for transit use. My advice is to stay off interstate highways. I would rather do 15 hours of driving seeing all of the cool sites than do the same trip in 10 board to tears. Out west especially, many back roads are 70mph so speed is not a factor. Nevertheless, I travel between 55 and 60 because I don't like taking the fuel hit. | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 1588 Registered: 10-2006 Posted From: 75.58.183.66 Rating: N/A |
I've found 'simpler is better' to usually hold true in most cases. So learn to drive a stick, and enjoy 2- 3 or more miles per gallon. KISS FF | ||
| Jim Wilke (Jim Bob) (Pd41044039)
Registered Member Username: Pd41044039 Post Number: 678 Registered: 2-2001 Posted From: 184.0.13.120  Rating: N/A |
I drive stick. My wife CAN but refuses, hoping to force me to go to an automatic. I just can't buy the potential for a big tow bill (stick rarely breaks without lots of warning) plus the fuel hit. Dang, diesel was $1.30 when I got into this insanity. I don't make any more $$ than I did then. | ||
| John & Barb Tesser (Bigrigger)
Registered Member Username: Bigrigger Post Number: 553 Registered: 9-2007 Posted From: 96.42.5.35 Rating: N/A |
I feel your pain Jim. I just fueled up at almost four bucks a gallon. Thats crazy considering what we ask to come in and play doesn't usually cover the fuel any more. I hope I am "laying up treasures in heaven". John | ||
| joe padberg (Joemc7ab)
Registered Member Username: Joemc7ab Post Number: 553 Registered: 6-2004 Posted From: 66.38.159.33 Rating: N/A |
John The problem is your OB, he has allready exceeded the increase in the debt ceiling with another half trill, if you could only fathom and understand the amount of new "money" that is coming into circulation, then it should be no surpise or shock what you have to pay at the pump. And it looks to me that it is going to get only worse, not better. So much for the political rant from north of the 49th. It may not be BUS related, but yet it is, because it affects all of us when we have to fill that humongously thirsty tank. The only other option that I can see is to go camping in your own yard. We are fortunate enough to be able to do that, because we live on a rural acreage. Joe. Amazing what happens after a glass of wine!!!! | ||
| Sam Summers (Greyghost)
Registered Member Username: Greyghost Post Number: 95 Registered: 4-2011 Posted From: 166.233.148.29  Rating: N/A |
HI Rick I just bought a 1967 GM 4107 in June, 8/71 4 speed, 10-12 on the flat ground with 7-9 on the grades, testing it out on the way back from California to Oregon was cruising at 80 just to see what she'd do, I forget who here didn't like that but I wanted to know what it would do. Better mileage on a stick, it's what your going to be comfortable with, everyone has their likings, auto is nice but I'm keeping with the original set-up. Have fun whatever you get it's great and a worth while adventure. All aboard the Buffalo Train! Sam | ||
| John & Barb Tesser (Bigrigger)
Registered Member Username: Bigrigger Post Number: 554 Registered: 9-2007 Posted From: 96.42.5.35 Rating: N/A |
Rick, How old is your engine? I am thinking maybe mine doesn't get that good of mileage because it's got a lot of miles on it. I probably only average 7 or so and I don't think I could get 80 MPH out of mine. I can coax it up just over 70 but that's it without a downhill grade. Maybe my 4107 has lower rear gears? Joe, our problem is polititians in general. The only thing they are concerned with is getting elected again. I truly believe they put that ahead of what's best for the county. John | ||
| Tom Christman (Tchristman)
Registered Member Username: Tchristman Post Number: 332 Registered: 1-2006 Posted From: 66.218.33.156 Rating: |
Granted you will have better fuel mileage with a manual transmission. But with a V drive, a 4 spd is just not enough gears. Try starting on a hill, or backing up hill into a campsite, and you'll quickly burn up the clutch. Burn out a clutch and you've just eliminated all savings in fuel from running the manual with all your careful shifting. Take it from an old truck driver like me that drove nothing but 13spds for over 1.3 million miles-there is nothing quite so satisfying and performs better then an Allison transmission-especially on an up hill when they are doing road construction and you're stopping and starting going through the construction site. The V730 is a tough, reliable transmission (basically a HT740 without 1st gear). My bus has 4.56 rear gears that with 11R-24.5's give me a comfortable 1850rpm cruise at 58mph. If I need to step it up, I can cruise at 65mph just under 2100rpm. With the amount of driving that most do, drivability with the automatic supercedes the fuel mileage savings with the manual. Good Luck, TomC | ||
| Sam Summers (Greyghost)
Registered Member Username: Greyghost Post Number: 96 Registered: 4-2011 Posted From: 166.233.28.199 Rating: N/A |
John (Rick, How old is your engine? I am thinking maybe mine doesn't get that good of mileage because it's got a lot of miles on it.) If you meant mine, it has about 45,000 on engine.. Sam | ||
| John & Barb Tesser (Bigrigger)
Registered Member Username: Bigrigger Post Number: 555 Registered: 9-2007 Posted From: 96.42.5.35 Rating: N/A |
Yup Sam, I meant you... dont ask me where Rick came from, its been that kind of weekend! That may be why yours is getting better mileage than mine. I don't have any idea how many miles mine has on it, but I'm thinking a lot. One of these days I am just going to have to "bite the bullet" and freshen it up some. We love the old 4107 though. John |
