| Author | Message | ||
| quantum merlin (Quantum500)
Registered Member Username: Quantum500 Post Number: 2 Registered: 8-2007 Posted From: 70.57.21.17 Rating: |
Anybody tried it? Can the drive train hold it? Will the extra wieght cause any problems? | ||
| James Smith (Tomcat)
Registered Member Username: Tomcat Post Number: 63 Registered: 8-2005 Posted From: 207.200.116.13 Rating: N/A |
If I recall correctly, some buses were built that way from the factory to run the Canadian Rockies. At least one still out there I believe. Jay 87 SaftLiner | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 103 Registered: 8-2006 Posted From: 74.32.80.38 Rating: N/A |
I heard some Mci 6s had v12s | ||
| Laryn Christley (Barn_owl)
Registered Member Username: Barn_owl Post Number: 74 Registered: 10-2006 Posted From: 151.199.95.252 Rating: N/A |
A 4501 might, but it would be too long to fit transversely in the rest. | ||
| joe padberg (Joemc7ab)
Registered Member Username: Joemc7ab Post Number: 137 Registered: 6-2004 Posted From: 66.38.159.33 Rating: N/A |
George Todd has / had one in his MC6. Apparently his plan is to replace it with an 8v92. My guess is that it would be fairly thirsty. Joe. | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 258 Registered: 8-2006 Posted From: 207.231.81.129 Rating: N/A |
Joe is right! All 100 MC6s were originally built with 12V71s and 4 speed sticks. Strong and fast, but they had troubles with that much power, and that much weight. So, about 80 of them were changed to 8V71s and 740 Allison on their first rebuild, in 1973. They were gutless, so they added turbos to them, which I guess helped a little. The gear ratio is so numerically low, (high speed) that they are hard on clutches, but will go over 90. There is an excellent article back in the archives about fuel economy in Detroits. IIRC, about 1700 rpm produces the best fuel mileage, and this thing gets about 8. One other thing to keep in mind is that an 8V92 produces the same power as a 12V71, with better fuel mileage, and its a foot and a half shorter! Length is the reason for my changeout, as there isn't enough room for an auto. George | ||
| Jack Conrad (Jackconrad)
Registered Member Username: Jackconrad Post Number: 615 Registered: 12-2000 Posted From: 76.1.180.218 Rating: N/A |
I know a person that had a 12V71 in an MC-7. The engine stuck out the back of the bus and the radiator was mounted behind the engine (similar to taking a complete truck engine with radiator assembly and sticking the whole thing in the MCI). He later removed it and sold it to a mine to replace a blown 12V71 that operated a rock crusher. He now has a 8-92 with similar radiator set up. Jack | ||
| quantum merlin (Quantum500)
Registered Member Username: Quantum500 Post Number: 3 Registered: 8-2007 Posted From: 70.57.21.17 Rating: N/A |
I think I have the size problem figured out and yes I know all about the MCI coaches that had 12v71's. I was more concerned with the extra wieght and extra power. I guess since 8v92's seem to be more popular....or easier to get a hold of. Has anybody had any troubles with the added wieght and power from one of these in a GM bus, or MCI for that matter. | ||
| Kyle Brandt (Kyle4501)
Registered Member Username: Kyle4501 Post Number: 364 Registered: 9-2004 Posted From: 65.23.106.193 Rating: N/A |
RE: Has anybody had any troubles with the added wieght and power from one of these in a GM bus? YES. GM's weren't designed for the weight or power of anything bigger than a 8V71. (some, not even that much) The Alum structure will eventually crack & fail from the stresses from the designed power train, that's why the routine garage maintainence included inspecting the whole bus for cracks so they could be repaired before total failure. You can add reinforcement, but if you don't know what you're doing, you could be making it worse. Can you get away with it? Sure, but for how long? How long depends on lots of things, some of which come to mind: Past history of bus - how many miles? how much abuse? how many chatter starts with the clutch? Has the bulkhead been repaired? how well? how long ago? What is the condition of the rest of the bus? where was it operated? how much corrosion is present? A 4501 is the only GM Parlor Diesel coach that came with a T-drive. Mine has the 8V71NA & it is suprising how quickly it reaches 4th. What's the rush? spend the $$$ on paint & slow down so everyone can admire it as they pass  If you're in such a rush, why not fly? It'd be cheaper. If it were me & I wished to remain ground based with this much power, I'd look into modifying a cab-over into a monster class C motor home. | ||
| Douglas Wotring (Tekebird)
Registered Member Username: Tekebird Post Number: 239 Registered: 10-2004 Posted From: 71.230.14.180 Rating: N/A |
Kyle watch out the people who like to do the impossible may come out and admonish you.....and tell you they can put a 12-71 in there and tow a 2000# tounge weight 15,000# trailer for decades | ||
| Kyle Brandt (Kyle4501)
Registered Member Username: Kyle4501 Post Number: 365 Registered: 9-2004 Posted From: 65.23.106.193 Rating: N/A |
That's OK Won't be the first time I've been admonished. Won't be the first time someone was wrong. Won't be the first time someone was lucky & got away with something that sound reasoning & design doesn't support. I'm NOT saying it can't be done. I AM saying there is way more to it than most think & to have LONG TERM success, one needs to consider lots of things that tend to be taken for granted. And that there are really good reasons why you won't see it done more frequently. (most people that have enough $$$ to do something like that are smart enough to have found a way to do it better & cheaper) Buses are designed as capital equipment to be used in the generation of income & proffit for its owner while the public pay to ride in it. Cars are designed as a commodity to be the personal property of the end consumer who uses it privately. I find it interesting that some can't comprehend what this means in the design process. | ||
| Ron Walker (Prevost82)
Registered Member Username: Prevost82 Post Number: 331 Registered: 11-2003 Posted From: 66.82.9.56 Rating: N/A |
quantum merlin ... a 8V92ta weights are about the same as a 8V71. It's a couple of inch longer. Ron | ||
| Kyle Brandt (Kyle4501)
Registered Member Username: Kyle4501 Post Number: 367 Registered: 9-2004 Posted From: 65.23.106.193 Rating: N/A |
Oh yeah, What model are you interested in putting it in? Some only came with 4-71s or 6-71s. You are aware that the GM V-drive utilizes a left hand rotating engine. . . Then there is the minor detail of the limited selection of transmissions - Are any of those able to handle the increased power level? Also of note, the automatics used in the GM V-drives are notoriously bad on fuel mileage. Another thing - COOLING - How are you gonna cool the engine? GM's aint known for excess cooling capacity. I've done the hot rodding thing a time or two. Much less expensive to ask questions like you are doing now rather than on the side of the road with a pile of busted parts. BTW, my first question to the boards was along the lines of "how much power can you get out of a 8V92?" The answers included lots of information relating to the affected systems which I didnot understand at the time, but later, as I learned more, I was able to determine the posters that had the best answers & the posters that were, well, not so much. | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 475 Registered: 11-2005 Posted From: 63.97.117.54 Rating: N/A |
I thought about a 12V71 but have now decided to go to a 16V71 instead. I'm going to put it amidships and have an engine room just like on a tugboat. I'll only have two gears with a giant torque converter and triple tandem rear. | ||
| Kyle Brandt (Kyle4501)
Registered Member Username: Kyle4501 Post Number: 368 Registered: 9-2004 Posted From: 65.23.106.193 Rating: N/A |
Gus, What? no turbos & after coolers? That would be a show, smoking 12 tires! Turns would be fun | ||
| Austin Scott Davis (Zimtok)
Registered Member Username: Zimtok Post Number: 162 Registered: 9-2006 Posted From: 216.37.73.226 Rating: N/A |
OOOOO, How about a "MONSTER BUS" With 2 of those twin turbo Allison aircraft engines. OR Build a Jet powered bus to run the salt flats and set a speed record. . | ||
| J.L.Vickers (Roadrunnertex)
Registered Member Username: Roadrunnertex Post Number: 31 Registered: 10-2006 Posted From: 76.1.64.165 Rating: |
A 4501 is the only GM Parlor Diesel coach that came with a T-drive. Well this is from the book GM Intercity Coaches. These GMC Coaches had a "T" Drive long before the PD-4501 in 1954. PGA-3702,PD-3302,PD-2903.PDA-3703,PDA-3704 had 4/71 Detroits. And last but not least the one and only PD-4901 Golden Chariot. jlv | ||
| Michael Sheldon (Msheldon)
Registered Member Username: Msheldon Post Number: 47 Registered: 10-2006 Posted From: 68.230.115.166 Rating: N/A |
Now Gus, the 12V is fine, just don't settle for a 71. THIS is the one you want: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=120153503354 | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 476 Registered: 11-2005 Posted From: 63.97.117.44 Rating: N/A |
Forgot to mention the twin turbos w/aftercoolers since this is two 8Vs tied together. I thought about Allisons but they don't have the torque, these are small engines compared to this tugboat engine I'm using. Anyway, those Allisons are too expensive now because all the air racers in Reno have about used them up. I want the 71s because they have dry sleeves and are easier to find. This one came from a Navy surplus tugboat that was in mothballs. My big problem is finding a driveline to handle it but I think one of those old military tank hauler trucks will do it. I know where one is sitting behind a warehouse. The front and rear tandems on these tractors steer and all three axles will drive/release by air. They also have tandem/steer fronts but I don't want them, I want to cut down on the number of tires. | ||
| Kyle Brandt (Kyle4501)
Registered Member Username: Kyle4501 Post Number: 370 Registered: 9-2004 Posted From: 72.147.48.9 Rating: N/A |
Hey JL, Thanks for pointing that out. I should have qualified my statement to be for the 'modern era' buses from GM Gus, I've often considered making a mid-engined bus by 'simply' placing a modified bus body on a truck frame. That would enable one to haul one heck of a trailer too | ||
| quantum merlin (Quantum500)
Registered Member Username: Quantum500 Post Number: 4 Registered: 8-2007 Posted From: 71.216.90.94 Rating: N/A |
I'm glad I got so much response. Realistically I would probably never have the time to do such a conversion. I do happen to have a low hour 12v71 just "sitting around" so of course you have to think about what to put it in. Some of the responses got me to looking at exact dimensions and wieghts. Interesting stuff to say the least. 8v92 wieghs about 300lbs more than an 8v71. 12v71 wieghs about 1800lbs more than an 8v71. No real shocker there. A 12v92 wieghs 600lbs less than a 12v71.....! To top it all off it is dimensonally smaller...just by a little. | ||
| marvin pack (Gomer)
Registered Member Username: Gomer Post Number: 86 Registered: 3-2007 Posted From: 76.4.145.234 Rating: N/A |
will any of that fit my 66-vw bus? will I have to modify MUCH? LOL gomer | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 478 Registered: 11-2005 Posted From: 63.97.117.52 Rating: N/A |
gomer, If you put it in the back you will have to move your battery to the front. Otherwise, I see no problem. | ||
| Kevin Black (Kblackav8or)
Registered Member Username: Kblackav8or Post Number: 73 Registered: 8-2005 Posted From: 24.152.174.198 Rating: N/A |
I would like to see and hear something like that. A big cam cummins will still out pull one though. They are fast and more torquey then a 8v but aren't giant killers. Want to really crush buses going up the grapevine? Cummins KT with a 10 or 15 speed OD. A Super 10 would be a nice match. Semi-automatic shifting. KT's are thirsty but less so then a 12V is. Who's gonna build the Monster Bus. Whatever happened to the guy with the 3408 bus? | ||
| ned sanders (Uncle_ned)
Registered Member Username: Uncle_ned Post Number: 39 Registered: 5-2005 Posted From: 68.213.111.136 Rating: N/A |
I believe one of the 12v92's would be just right for my "box" my 63 econoline toad. Might have to strech the wheel base a little.Then when "huggy" had problems i could just push. uncle ned | ||
| Gus Causbie (Gusc)
Registered Member Username: Gusc Post Number: 484 Registered: 11-2005 Posted From: 63.97.117.17 Rating: N/A |
Ned, You will need to move your battery to the front just like in Gomer's VW. | ||
| Tim Brandt (Timb)
Registered Member Username: Timb Post Number: 63 Registered: 10-2003 Posted From: 72.145.182.9 Rating: N/A |
Kyle, No need to look for a truck chasis the AFC Brill was a mid engine | ||
| Jeffrey Smith (Greenhornet)
Registered Member Username: Greenhornet Post Number: 58 Registered: 12-2006 Posted From: 76.110.30.60 Rating: N/A |
"Now Gus, the 12V is fine, just don't settle for a 71. THIS is the one you want: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=120153503354" WOW! That looks insane....I want one! ;Þ |
