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Benjamin

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  1. Benjamin
    Yes, VTA's 9200s/9300s were Flxibles, and yes they did have Voiths. The 1984 Phantoms (units 1469-1483) had a mechanically-controlled 6V92TA engine whereas the 1990-93 Phantoms had the DDEC (Detroit Diesel electronic controls) version of the same engine. Other than that they performed more or less the same. ~Ben
  2. Benjamin
    The 1700s are gone, I know... but the remaining 1900s are still around. Yes, 2001-2022 do still exist. ~Ben
  3. Benjamin
    They are Voith D864.5 units. ~Ben
  4. Benjamin
    Somewhat... And no, no Flxible Metro ever got out with the B400R... those examples used ZF ECOMAT transmissions instead. ~Ben
  5. Benjamin
    Meaning no overdrive? ~Ben
  6. Benjamin
    This question is for the experts of the GATRA bus fleet: is it true that the 1982 and 1983 Orion I's they ran (8217-8219 from 1982, 8320-8322 from 1983) came with Detroit Diesel 6V92TA engines? If yes, then the transmission behind them would be the Allison HT740 (8217-8219) or the HT747 (8320-8322). ~Ben
  7. Benjamin
    Can anyone please enlighten me as to whether David Fisher's information regarding the 1983-84 Orion I's 8401 to 8416 (Detroit Diesel 6V71N engine and Allison HT747 transmission) is true? Link: http://mt.davidfisher.biz/mtfleet.html There actually is an 8406 delivered to Mississauga Transit in this list: http://www.angelfire.com/ca/TORONTO/builders/orion1.html He says 8402 was delivered in May 1983, the list above says May 1984 (all other dates are correct). Bus 8416 was on loan to the National Research Council in Ottawa; Mississauga then ordered one new Orion I model 01.508 (built 8/1985) to replace 8416. Additionally, the MiWay Wiki at http://en.wikipedia.org/wiki/MiWay says that 8823 among the 1988 Orion I's was CNG powered on initial delivery. David Fisher's page says 8825 was CNG powered initially and later converted to diesel--not true, as it was actually the only one to get out with the Detroit 6V92TA engine and Allison HT748 transmission. ~Ben
  8. Benjamin
    Any number at the end in the HT74x line (as represented by "x") refers to the design variation. Speed has nothing to do with it, except in terms of shift point adjustment. The HT747 was introduced in 1982 exclusively for use in domestic diesel public transit buses with a total rated weight of 60K GVW with all passengers loaded, for use with engines producing up to 345-365 hp and 1100 lb/ft of torque. The 747 is distinguished from the 740 by means of a forged lockup piston "for added durability" and a triple-gear oil pump "to increase coolant and lubrication flow." The electronic ATEC control variant of the HT740 was the HT741; while the HT748 complimented the HT747 for the transit bus industry. ~Ben
  9. Benjamin
    http://www.dal-trans.com.au/Products/HT-740_-HT-747-1.pdf Here's a 1987 HT740 and HT747 specification brochure. The HT747 was used for city and transit bus applications only, and was rated for up to 365 NHP (net HP) maximum and 1100 lb/ft max TQ. Vehicle weight max 60K GVW. Governed speed range 19/2400 RPM. The HT747 is not electronically controlled but it can still be distinguished from the original HT740 by means of a forged lock-up piston for added durability and a three-gear oil pump to increase coolant and lubrication flow. Per the official Allison transmission history (per its website), it was introduced in 1982-83 for use in the transit coach industry. The HT741 and HT748 electronically-controlled automatic transmissions follow the same logic; the HT748 is the one with the forged piston and triple-gear oil pump. ~Ben
  10. Benjamin
    Shift point adjustment, as I said before. ~Ben
  11. Benjamin
    Jared, Well, the 1400s are indeed staying longer since Gillig is still alive and kicking... and they are the same company making Tri-Met's current low-floor buses. And yes, the 3100s and 3200s are often confused... that will manifest further after the 3300s come in later. But then again, the same can be said for all the New Flyer LF buses... the 22/2300s and 2500s, and the 26/2700s and 2800s. Merlo currently has all the 2800s (and the new-look LFR 2900s), while Center has most 26/2700s and Powell all the 22/2300s and roughly half the 2500s. ~Ben
  12. Benjamin
    On the GMC RTS II and the Flxible Metro (and Grumman 870/Metro), the rear-end ratios are 5.38:1 city and 4.56:1 highway. Transmission gear ratios are 1.81 (1), 1.22 (2) and 0.875 (3). The Ikarus 286 (the U.S. version of the 280) used a 4.3:1 rear end ratio for a top speed of 60 mph with the Cummins NHHTC engine and Allison HT740 transmission. ~Ben
  13. Benjamin
    I think the HT740 and HT747 are equally fast: same gear ratios of 3.69 (1), 2.02 (2), 1.38 (3) and 1.0 (4). I think the only thing that makes one of these 740 variants shift faster is the shift point adjustment. Some buses may have different rear end ratios: city buses are usually geared for up to 55 mph with direct-drive transmissions, so a 4.56:1 rear end is used on most applications; highway gearing for up to 65 mph is 4.1:1. Over-the-road coaches such as the MCI 9 series and the A/C series have a 3.73:1 rear end which really makes them go faster. ~Ben
  14. Benjamin
    BUMP For Jared Kam and others... how do you feel right now, now that all the 1700 series Flxible Metros seem to have vanquished? That of course would mean Merlo is ready for new occupants in 3231-3260 (the last 30 of the FY2014 budget order to be delivered, along with the first few 3300s and the 30-foot 3400s). Center Garage, too, is to acquire more 3200s as well as some 3300s and 3400s. ~Ben
  15. Benjamin
    C-TRAN has recently parted with its historical bus, number 2192, a 1976 GMC T6H-4523N. It was one of the last U.S.-built New Looks, being powered by the run-of-the-mill Detroit Diesel 6V71N engine and the Allison V730 transmission. Whoever's interested in it please buy! It was originally delivered as number 92 when the city of Vancouver, WA began its own citywide bus service, when the old Vancouver-Portland Bus Company ended in 1976. ~Ben
  16. Benjamin
    Not quite. "B" actually means "brake" (retarder brake). "ATEC" means Allison Transmission Electronic Controls, just as "DDEC" would mean Detroit Diesel Electronic Controls. So it would be HTB748 ATEC. ~Ben
  17. Benjamin
    I had been following the TriMet interactive map for three days straight now and it appears all the remaining 1992 Flxibles (the 1700s) have been canned--none of the Merlo-based commuter and express runs had them, either. Is this true? ~Ben
  18. Benjamin
    That is the electronic equivalent of the HT747, and most OTR (over the road) coaches used the original hydraulic HT740, even those as late as 1996-97 (all the MCI MC12 did have that, for example) when the B400R and B500R were already being used in such applications, regardless of whether or not the engine mated with it had electronics. ~Ben
  19. Benjamin
    The Wiki page to this bus in the original post (link above) shows that error (see description box on said page) and possibly a few other sites... and I was suspicious of that since like I said before, the 6V53 was not used in the Orion I after 1982 other than the last 30-foot buses delivered to Ottawa in early 1983. ~Ben
  20. Benjamin
    Which would mean the correct engine in this bus would be the 6V71N, not 6V53N. ~Ben
  21. Benjamin
    1969 from official Cummins literature. Yes, the SCRTD 7100s did use that engine. Here is 7103 in action: ~Ben
  22. Benjamin
    Around 1978... that was the engine used in the first few Grumman 870s built for MARTA (3001 to 3005). ~Ben
  23. Benjamin
    I am wondering if anyone has any application data regarding the Allison automatic transmissions used in our favorite buses of the 1970s, 1980s and early 1990s? Typically, these are the transmissions to be used in city buses: 100-175 hp = AT540, AT545 175-210 hp = MT640, MT(B)643 210-250 hp = MT(B)644, MT(B)647, MT(B)648 175-275 hp = MT(B)654CR, V730, V/VR731(RH) 275 hp or more = HT740, HT(B)741, HT746, HT747, HT(B)748 ~Ben
  24. Benjamin
    Also, the Neoplan Skyliners that were built for LACMTA (then SCRTD) in 1975--units 9900 to 9921--used the Cummins VTB903 diesel engine mated to the Allison HT740 transmission. ~Ben
  25. Benjamin
    Or even the ZF Ecomat 5HP600 or Voith D864. ~Ben
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