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Message |
bill chisholm (Billybandman)
Registered Member
Username: Billybandman
Post Number: 108
Registered: 2-2001
Posted From: 198.236.64.22
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 24, 2007 - 10:34 am: | |
FYI,
I drove an MC 8 the other day from Spokane, WA to Portland Or that had been converted to a Series 50 with and Auto Tranny, not sure if its a 740 or 745. Absolutely was a rocket, both out of the hole and top-end, had it easily up to 75mph, would've gone faster but the State wouldn't see my road test the same way as me. Been driving charter buses 32 years, all types, and can say that I was really impressed with this set-up, and the vibration at idle didn't seem noticable at all. I drove it to a Bus Sales company, I will post if he decides to sell it. |
Jerome Dusenberry (Jerry32)
Registered Member
Username: Jerry32
Post Number: 2
Registered: 1-2007
Posted From: 148.78.243.51
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 25, 2007 - 5:28 pm: | |
What is a series 50? I have a list of DD's and don't see a mention of one? |
norcal kyle (Kylexisxrad)
Registered Member
Username: Kylexisxrad
Post Number: 110
Registered: 12-2005
Posted From: 216.220.208.126
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 25, 2007 - 6:21 pm: | |
its the 4(?) cylinder version of the Series 60, which is DD's heavy duty 4 stroke engine. from what I've heard its commonly compared to the 6v92. its what Greyhound re-powered all of their remaining MC-12's with to comform to the new emissions standards. a great motor from what I've heard, and billys testament comfirms that.
kyle in norcal
1980 Eagle 10 #30223 |
Henry 96A3 (Hank)
Registered Member
Username: Hank
Post Number: 75
Registered: 11-2005
Posted From: 69.129.124.111
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 25, 2007 - 6:53 pm: | |
I'm jeolous. I don't know nothin about DDEC systems other than they sound expensive and tricky to work on. Is there such a thing as a mechanical series 50/60 engine? I'm guessing there isn't. I love my two stroke but the oil leaks really irriate me. My brother drives truck and his Freightliner has a series 60 with about 500K miles on it....not a single drop of oil. The underside of the engine is complete dry. You'd think that after 60 years of production on the 2 stokers they would have figured out how to keep them from leaking. Someday when I'm rich I'll repower (not holding my breath on that!) Meanwhile I keep lots of 40wt on hand.
Hank |
Steveggt (Steveggt)
Registered Member
Username: Steveggt
Post Number: 7
Registered: 12-2006
Posted From: 71.116.87.220
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 25, 2007 - 9:42 pm: | |
Hi Group!
"norcal kyle" is correct in stating that the Series 50 is basically a 4-cylinder version of the 6-cylinder Series 60. Power output is typically around 275-325 hp range (like a 6v92), but there's no mechanical version...both Series 50/60 are DDEC.
I've found that the 50/60 have more torque in the lower rpm range and you don't have to be as conscious of keeping the engine wound up like the 53/71/92 series two-strokes...but it's not an "open invitation" to lug the engine anyway.
I've also noticed that the "older" DDEC versions seem to perform better. As emissions requirements changed and became more stringent, the DDEC programming changed as well. The DDEC-II motors burned down the road! The DDEC-III/IV feel a bit less powerful due to catalytic converters, exhaust/particulate-matter traps, and variable-degree turbocharger vanes. Of course, with the DDEC, you have some "play" within the program's parameters to adjust the engine's performance.
The only drawback I can think of is that I don't feel as much compression-braking from the 4-strokers. I learned how to drive on inline 6-71's with the manual 4-speed tranny and really liked their compression braking even without jakes. The 4-strokers sometimes feel like they'll run away on a downhill if you're not aware of what's going on. |
jim morrison (Jim_morrison)
Registered Member
Username: Jim_morrison
Post Number: 68
Registered: 11-2006
Posted From: 72.142.29.218
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 25, 2007 - 9:52 pm: | |
is that what they call[ progreasive shifting] , low rpm's shift to a higher gear and on ya go ???i could be wrong on the way it is or dune, but i have heard it that way.....jim |
Buswarrior (Buswarrior)
Registered Member
Username: Buswarrior
Post Number: 992
Registered: 12-2000
Posted From: 70.48.193.224
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 26, 2007 - 9:04 pm: | |
Hello Jim.
Sounds like you've got it.
Progressive shifting is an economy minded strategy, as well as for performance. Remember that it takes time for the engine to spool back down from high RPM, and the vehicle is slowing while you are waiting for the drop. A short, sharp boost in each gear, and get into the next gear asap puts you down the road quicker than winding it out in the lower gears. The trick is short shifts in the lower gears and stretch it out as you get higher in the gears.
For economy, you upshift at the earliest possible revs to catch the next gear where you will have some power. The 4 stroke motors love to pull from down low in the RPM range. A 2 stroke DDC would not enjoy this strategy, and neither would the driver, because they don't make enough power down low in the RPM.
My Freightliner with ISM Cummins with a 10 speed, approximately, you shift 1-2 at 1000, 2-3 at 1200, 3-4 1400, 4-5 1500, 5-6 1600, and the rest at 1700. The governor is at 2100 and you never take the motor up there on acceleration.
I'm geared to run 55 mph at the 1450 sweet spot for the motor.
If you have a bigger displacement engine, or if you have more gears, you shift earlier, and the Big Cats, even lower again.
Lower RPM is one of the ways that the 4 strokes get great fuel economy.
Series 50 and auto trannies are coming to the transit auctions near us very soon. Buy a donor coach and swap it all over into the older MC7,8,9 and early 102's.
happy coaching!
buswarrior |
Mike Eades (Mike4905)
Registered Member
Username: Mike4905
Post Number: 141
Registered: 12-2000
Posted From: 68.207.200.143
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 27, 2007 - 2:54 pm: | |
Just wondering anyone has driven the new ten speed automatic. I just drove one the other day and thought it was a truck trannie what shift pattern. Mike |
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