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Benjamin

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  1. Benjamin
    Has anyone here heard of the Allison MT654CR 5-speed close-ratio automatic transmission? I know it seemed most popular outside North America; many articulated buses in those countries used it including the Volvo B58 and B10M. Input power: 300 hp max Input torque: 950 lb/ft max Input speed: 1900-3000 rpm Transmission gear ratios: 1st: 4.17:1 2nd: 2.21:1 3rd: 1.66:1 4th: 1.27:1 5th: 1.0:1 Reverse: 10.76:1 Torque converter ratios: TC430: 3.59:1 (crawl ratio: 14.97:1) TC495: 2.21:1 (crawl ratio: 9.22:1) TC496: 1.83:1 (crawl ratio: 7.63:1) TC497: 2.7:1 (crawl ratio: 11.26:1) Crawl ratio: first gear ratio x torque converter ratio ~Ben
  2. Benjamin
    Does anyone here remember the Blue Bird "City Bird" transit bus? It was produced from 1976 to 1986. For most of its run it used a Detroit Diesel 6V53 engine (naturally aspirated to 1979; turbocharged from 1980), switching to 6V71TA power for its last two model years (1985-1986). Engine list: Detroit Diesel 6V53N (1976-1979) Detroit Diesel 6V53T (1980-1984) Detroit Diesel 6V71TA (1985-1986) Transmission list: Allison MT640 (1976-1977) Allison MT643 (1978-1984) Allison MT644 (1985) Allison MT647 (1986) Hear a 1983 City Bird in action: https://www.youtube.com/watch?v=3Ip2uNRyYVg (audio and picture by Marcos Ruiz) ~Ben
  3. Benjamin
    That picture has been removed. ~Ben
  4. Benjamin
    I do. I was logged in when I clicked those links. ~Ben
  5. Benjamin
    Those are bad links, meaning I may not have permission to see them. Now what do I do? ~Ben
  6. Benjamin
    You're welcome. ~Ben
  7. Benjamin
    Exactly. The SMART units would've had the HT748 transmission. ~Ben
  8. Benjamin
    There were also a few GMC and TMC RTS T-drive prototypes. The GMC ones (three T8J204s built in August 1982, and one T8J605 built November 1984) never made it beyond the prototype stage, although SMART of Detroit did order two TMC RTS II's that were (model T80207) - those were built in 1992 (units 9368-9369). ~Ben
  9. Benjamin
    Today (8-28-2014): 3253 on route 20 3254 on route 48 ~Ben
  10. Benjamin
    Today (8-21-2014): 3243 on route 56 ~Ben
  11. Benjamin
    Today: 3238 on route 88 3239 on route 62 3242 on route 33 ~Ben
  12. Benjamin
    They used Allison HT740 transmissions if the engine was non-DDEC (Detroit Diesel electronic controls), while for DDEC-equipped 6V92TAs the HT741 ATEC (Allison Transmission electronic controls) was used. ~Ben
  13. Benjamin
    Latest 3200 sightings: 3231 on route 12 3232 on route 20 3233 on route 48 3235 on route 76 3236 on route 52 3237 on route 62 ~Ben
  14. Benjamin
    http://en.wikipedia.org/wiki/Cummins_C_Series_engine Was later known as the C8.3 and ISC. ~Ben
  15. Benjamin
    Does anyone remember what the exact serial/VIN numbers are for Grey Goose Bus Lines' 1983 Orion I suburban buses numbered 101 to 197 (later Gray Line East 4101 to 4197)? Only three are known: D5493730 (number 125/4125) D6702732 (number 160/4160) D5498741 (number 165/4165) Number 160/4160 is also one of a handful of Canadian-bound Orion I's to be built in New York instead of Ontario. From 1982 to 1984, it should be known that Orion I serial numbers had the first three of the six digits in the serial number following the model year code (C=1982, D=1983, E=1984) represent the production line sequence. It began when they built Markham Transit 2016, serial number C5356457, which left the Mississauga plant as the 356th unit finished in May 1982, and ended with Whitehorse Transit 14, a model 01.506 bearing serial number E5563999, which left Mississauga as the 563rd unit finished in July 1984. For serial no. D5493730 it was the 493rd bus to leave the Mississauga plant whereas for serial no. D6702732 it was the 102nd bus to leave the Oriskany plant between (for some odd reason the first number in the plant sequence code jumped from 0 to 6 in early 1983). ~Ben
  16. Benjamin
    Does anyone remember anything about Jefferson Transit's two 1982 Orion I buses numbered 95 and 96? They came with Detroit Diesel 6V53T engines rated 225 hp, mated to Allison MT643 transmissions. By 1990 they were repowered to Cummins 6CT8.3 engines. JT also ran two 1984 Orion I's numbered 848-849. These came with Detroit Diesel 6V92TA engines mated to Allison HT747 transmissions. ~Ben
  17. Benjamin
    2B113937XD6702732 This appears to be another incorrect VIN. Why? This, which represents Grey Goose Bus Lines 160 (later Gray Line Tours 4160 and most recently Perimeter Transportation 692), like all Grey Goose's 1983 Orion I's, came with a Detroit Diesel 6V71N engine and Allison MT644 transmission. The "3" as the engine code would indicate a Detroit Diesel 6V53T engine; and buses like this clearly didn't sound like it. The correct VIN number for this unit should be: 2B1128271D6702732. This means this is one of a handful of those Canadian-bound buses to have been finished in Oriskany instead of Mississauga. Thank you, Ben
  18. Benjamin
    I am sure most of you know about the Allison HT740 and HT747 transmissions, but the lower-rung MT644 and MT647 are not quite fondly as remembered. These share some of the same parts, such as torque converters. The MT644 was designed for engines up to 300 hp and 780 lb/ft of torque, whereas the later MT647 ups the input torque rating to 950 lb/ft. But for transit buses, these ratings will be different; for now I know the input hp limit for bus engines is 250. The MT648 was the electronically-controlled equivalent of the MT647. Torque converter ratios are 2.21 (TC495) and 1.92 (TC494). The HT740 was designed for engines up to 425 hp and 1300 lb/ft of torque, but in transit buses those ratings are reduced to 350 hp and 1100 lb/ft. The HT747, with its special three-gear pump for better coolant flow, is used only in transit buses and is rated for engines producing up to 350 hp and 1100 lb/ft. The HT741 and HT748 are the respective electronic equivalents of the HT740 and HT747. Torque converter ratios are 3.04 (TC470), 2.21 (TC495), 2.09 (TC499) and 1.83 (TC496, not available for HT747). I also want to know whether or not any buses that originally came with the MT644 or MT647 were changed to the HT747 or HT748 transmissions for durability reasons shortly after initial delivery or during their mid-life overhaul? So far I know a few buses had swapped out their MT644 or MT647 transmissions for HT747s or HT748s: Timmins Transit (Timmins, ON) 1982 Orion I 01.504 52-54 (54 was later resold to Ajax Transit as 2044) Mississauga Transit (Mississauga, ON) 1983 Orion I 01.504 8401-8404 Mississauga Transit 1984 Orion I 01.506 8405-8416 (8416 was resold to the National Research Council shortly after initial delivery) Mississauga Transit 1985 Orion I 01.508 8501 (replaced 8416) Vaughan Transit (Vaughan, ON) (later York Region Transit) 1987 Orion I 01.502 517-518 (original 6V71N engines were also reportedly changed to 6V92TA MUI's) University Transit Service (Charlottesville, VA) 1983 Orion I 01.506 5139-5239 and 5337 ~Ben
  19. Benjamin
    The curb weight of the Orion I is 24,100 lbs. GVW. The 6V92TA is MUI (mechanical unit injection). ~Ben
  20. Benjamin
    Has anyone ever determined which torque converter ratio is best for each engine/transmission combo? Example 1: Allison AT545 transmission with TC290 (1.72:1) torque converter behind Cummins B5.9 190 hp (475 lb/ft) engine Example 2: Allison MT643 transmission with TC360 (2.86:1) torque converter behind Cummins B5.9 210 hp (485 lb/ft) engine Example 3: Allison MT644 transmission with TC494 (1.92:1) torque converter behind Detroit Diesel 6V92TA 253 hp (766 lb/ft) engine Axle torque ratings: calculated input torque to axle, determined by: T = maximum gross engine torque (lb/ft) N1 = lowest transmission forward gear ratio N2 = torque converter stall ratio (2.5 or specific value for automatics, or 1 for manuals) Say you have a Detroit Diesel 6V92TA MUI (mechanical unit injection) engine mated to an Allison MT644 automatic transmission, being used in an Orion I transit bus. Allison recommends the transmission not exceed more than 740 lb/ft of input torque from the engine for transit bus applications. Only two TC (torque converter) ratios were produced for the MT644: 1.92 (TC494) and 2.21 (TC495). As the 6V92TA 253 hp engine has 766 lb/ft of torque, the 1.92 TC ratio would be best suited to the transmission. Otherwise, the Allison HT747 transmission (for engines up to 345 hp/1100 lb/ft) is recommended. 766 x 3.58 x 1.92 = 5,265 lb/ft input torque to axle. If anyone knows what the recommended input torque to axle rating is for a Rockwell R143 series rear axle with 4.63 and 4.11 ratios, please try to answer. ~Ben
  21. Benjamin
    Is it true that the CyRide 1983 Orion I 01.506 numbered 1408 (later 908) had the Detroit Diesel 6V71TA engine and Allison HT740 transmission? According to the engine code in its VIN number (1) that you have here, it did. All other Orion I's in the CyRide fleet had the naturally-aspirated 6V71N (rather than the 6V92TA), even through as late as 1988. 1=Detroit Diesel 6V71TA 2=Detroit Diesel 6V71N 7=Detroit Diesel 6V92TA ~Ben
  22. Benjamin
    Apparently, Jefferson Transit (Port Townsend, WA) repowered their 1982 Orion I buses with Cat 3208T engines around 1989. Chris Osbjornsen told me via Facebook chat that the one bus in this fleet JT still had, number 96, has that engine in place of the original 6V71N Detroit Diesel. ~Ben
  23. Benjamin
    You're welcome. ~Ben
  24. Benjamin
    His is HKT120. http://www.youtube.com/HKT120 ~Ben
  25. Benjamin
    In the meantime, here is Zack Willhoite's video of a 1985 Phantom with the same powertrain (Pullman Transit 104). ~Ben
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