DD Series-50 Flaws, or poor CTA Maintainance?

[sw4400]

Is the Detroit Diesel Series-50 engine a lemon engine, or is CTA maintainance that bad? I've noted that many of the 5800's used to squeal so badly when being driven, like a belt or pulley was wearing out often. The 6000's do this too, like #6077 yesterday on #78. When the bus hit 2nd and 3rd gears, a loud squealing sound started in the engine until curbed for a light or to drop off/pick up passengers.

[daerah]

A little bit of both. Most agencies are in the process of phasing out Detroit Diesel all together, especially the series 50. For example, LACMTA "LA Metro" has phased out their high floor new flyers (New Flyer C40HF) from series to cummins, and I believe next they will retrofit the low floor flyers from series 50 (New Flyer C40LF), to cummins as well

cta probably dont maintain their engines as well as they should, be that,..their trying to cut corners on costs in all avenues within the company except where it should be...at the head. However, cummins is a much better and reliable engine, which lower costs to maintain them.

[jacksone44]

A little bit of both. Most agencies are in the process of phasing out Detroit Diesel all together, especially the series 50. For example, LACMTA "LA Metro" has phased out their high floor new flyers (New Flyer C40HF) from series to cummins, and I believe next they will retrofit the low floor flyers from series 50 (New Flyer C40LF), to cummins as well

cta probably dont maintain their engines as well as they should, be that,..their trying to cut corners on costs in all avenues within the company except where it should be...at the head. However, cummins is a much better and reliable engine, which lower costs to maintain them.

I would agree, but I think with the CTA buses it more of a maintenence issue than the actual quality of the engine.

Metro in St. Louis had some Flx's with this engine back in the 90's and they ran perfectly (or close to) until retirement. But St. Louis also maintains the hell out of their buses, and was voted as having one of the best maintenence programs in the country as of late last year.

[BusExpert32]

Is the Detroit Diesel Series-50 engine a lemon engine, or is CTA maintainance that bad? I've noted that many of the 5800's used to squeal so badly when being driven, like a belt or pulley was wearing out often. The 6000's do this too, like #6077 yesterday on #78. When the bus hit 2nd and 3rd gears, a loud squealing sound started in the engine until curbed for a light or to drop off/pick up passengers.

Wow. Was it actually #6077? BusHunter reported that it was transferred to 74th a few weeks ago.

[MT0851]

Up here at Mississauga Transit the Series 50 can be best described as a nightmare. Using a 4 cylinder engine in the transit application was a big mistake. Philadelphia is currently in the process of replacing all of their Series 50 equipped D40LFs with Cummins ISLs as far as I know.

[Busjack]

Looking around, it appears that while the DD50 was EGR, it didn't meet 2007 requirements and was discontinued. Also, it appears that DD is part of Daimler, and they don't sell to the transit bus industry anymore.

Is it possible that because DD only made a half-hearted attempt at a clean diesel engine, that's why they plugged up the traps on the NABIs, providing another reason for their demise?

[Archon]

Milwaukee's (MCTS) Series 50's make the same noise. And they drink oil like crazy too And vibrate when at a layover you got to put the fast idle on or everything starts to come lose inside the bus. We have 146 of these an will have them for another 4 years.

[MT0851]

Looking around, it appears that while the DD50 was EGR, it didn't meet 2007 requirements and was discontinued. Also, it appears that DD is part of Daimler, and they don't sell to the transit bus industry anymore.

Is it possible that because DD only made a half-hearted attempt at a clean diesel engine, that's why they plugged up the traps on the NABIs, providing another reason for their demise?

There's lots of stories behind the demise of the Series 50, the one which makes the most sense is that they bailed out on the transit bus industry because it wasn't worth investing in anymore due to Cummins practicly dominating the sector.

However, I expect a comeback pretty soon, what Daimler wants to do is limit DD to only be able to sell engines to companies under the Daimler Corporation. On the flip side all truck and buses made by manufacturers under the Daimler Corp. (Orion, Setra, Freightliner, etc) will only be made available with DD engines.

[Busjack]

... On the flip side all truck and bus manufacturers under the Daimler Corp. (Orion, Setra, Freightliner, etc) will only be made available with DD engines.

Since Orion's main product seems to be the BAE hybrid, what engine do they put in there?

[RailBus63]

Since Orion's main product seems to be the BAE hybrid, what engine do they put in there?

Cummins ISB.

[artthouwill]

Is the Detroit Diesel Series-50 engine a lemon engine, or is CTA maintainance that bad? I've noted that many of the 5800's used to squeal so badly when being driven, like a belt or pulley was wearing out often. The 6000's do this too, like #6077 yesterday on #78. When the bus hit 2nd and 3rd gears, a loud squealing sound started in the engine until curbed for a light or to drop off/pick up passengers.

Great question. I've never heard that noise on the Gary Metro RTSs which had them, nor have I heard that noise on Metro transits dreaded Gilligs. I've only heard that squealing noise on CTa's 6000 Flx. My observation is too limited for me to call it.

[Van2001ko]

Up here at Mississauga Transit the Series 50 can be best described as a nightmare. Using a 4 cylinder engine in the transit application was a big mistake. Philadelphia is currently in the process of replacing all of their Series 50 equipped D40LFs with Cummins ISLs as far as I know.

Not all of the Series 50 New Flyer D40Lfs will get Cummins ISL. Only the Series 50 EGR which are in their 2003-2004 New Flyer D40LFs which are in the process of being retrofitted with Cummins ISL. but yea I agree completely that using a 4 Cylinder engine on a bus is a horrible idea. And yes the DD50 is crappy here in SEPTA-land as well.

the noise is really the radiator fans coming on.. The belts driven them is what cause this noise. This apparently is apparent on some of our (septa) new flyers as well.

[speedracer1407]

Up here at Mississauga Transit the Series 50 can be best described as a nightmare. Using a 4 cylinder engine in the transit application was a big mistake. Philadelphia is currently in the process of replacing all of their Series 50 equipped D40LFs with Cummins ISLs as far as I know.

I'm somewhat surprised to hear that the Series 50 has a reputation for crapulence. Oddly, I thought the only decent thing about the CTA's horrible NABI artics was the drivetrain. For one, they never broke down on the hundreds upon hundreds of rides to and from work on the 147. For another, they were substantially smoother than the ISM and ISL engines installed on the NFs, both 1000 and 4000 series. And while they didn't exactly make the NABI artics a hot-rod, they shoved those horrible rattle-traps up to LSD speeds reasonably well. But I certainly wouldn't know what maintenance nightmares went on at the garages, whether CTA or elsewhere.

But I'm not so sure the 4 cylinder design was necessarily a major cause of their unreliability. The DD50 may have been flawed, but there's no good reason why a 4 cylinder should be inherently overstressed or unreliable compared to a 6 cylinder of similar displacement and power. After all, it's not like the DD50 was undersized; it had exactly the same displacement (8.9L) as the ISL currently used in all CTA 1640+ and 4000 series buses. NF's promotional specs also name the ISL as the engine available on non-hybrid 60ft artics, making a full 330 HP, similar to the DD50 in the NABIs. Conventional wisdom may suggest that spreading 280-330HP over 6 cylinders may be more reliable than over 4 cylinders, but the reality is that neither engine revs much over 2000 RPM, so rotational and reciprocal mass is less of an issue than it would be if one were trying to extract, say, 250 high-RPM HP out of a long-stroke 2.5L 4 cylinder gas engine in a sports car vs a 2.5L V6.

[Busjack]

....

But I'm not so sure the 4 cylinder design was necessarily a major cause of their unreliability. The DD50 may have been flawed, but there's no good reason why a 4 cylinder should be inherently overstressed or unreliable compared to a 6 cylinder of similar displacement and power. After all, it's not like the DD50 was undersized; it had exactly the same displacement (8.9L) as the ISL currently used in all CTA 1640+ and 4000 series buses. NF's promotional specs also name the ISL as the engine available on non-hybrid 60ft artics, making a full 330 HP, similar to the DD50 in the NABIs. Conventional wisdom may suggest that spreading 280-330HP over 6 cylinders may be more reliable than over 4 cylinders, but the reality is that neither engine revs much over 2000 RPM, so rotational and reciprocal mass is less of an issue than it would be if one were trying to extract, say, 250 high-RPM HP out of a long-stroke 2.5L 4 cylinder gas engine in a sports car vs a 2.5L V6.

I'm not going to be an automotive engineer, and I base whatever knowledge I have on Car and Driver, but note several inconsistencies here.

The first is that with diesel engines, the focus is more on torque than horsepower (it used to be called "stump pulling torque"). My Honda doesn't have a "high revving" V6, but it is hard to believe that its 240 HP from a 3.0 engine is almost enough to push an articulated bus.

The other point is that your 8.9L comparison is either supposedly to a lighter weight 40 foot bus (the heavier ones supposedly had the 11 liter), or an articulated with an electric motor boost. One would have to add the HP of the electric motor.

Finally (and probably making the prior two paragraphs irrelevant), the main complaint from CTA was that it was plugging the particulate filter, and the complaint here seems to be that it has a squeaky radiator fan belt (something that was eliminated from most cars around 1980). The displacement or the number of cylinders wouldn't have much of anything to do with those two things.

I also wonder if those things led to the retirement of the 5800s, even though they got new DD50 EGRs in about 2003.

[MTA Bus Orion V 104]

wow.

but why do you all hate DDS50?

there good engines and they sound good.

sure they may not be the best,but it has the best sounding right along with Cummins.

problary is CTA maintainance bad and Besides CTA is one of the top worst TAs.

also the DDS50 did NOT cause retirement (it did NOT make death tick sounds) to those NABIs,the NABI 60LFW had structural problems that cause the retirement, Beisde,the NABI 60LFW were worst bus built ever anyways.

Also 6 Cylinder engine aren't reliable neither,they have the same issue as well.

Remember when Mississauga Transit 1993 D60HF was making a death tick sound and that engine was 6 Cylinder and it had 6V92TA engine and made death Tick sounds and caused those be retire at 2005,they didn't last long. heres proof:

and this has happen to other buses before even if it had other engines that are 6 Cylinder so engines making Death Tick causes the bus to be retired or have to get repowered,well mainly causes to retire which the 6V92TA made death tick so they had problems before,but the 6V92TA engine was discontinued in 1994.

so 6 Cylinder would have problems as well.

I'll agree Cummins is better but the DDS50 sounds good.

Also NJ Transit NABIs had frame issues before and issues with the CAT engine and besides CAT engine are cheap piece of crap! thats why CAT engine doesn't make bus engine anymore

so any engine has problems a times.

Also LACMTA will also repower all the 2000-2005 NABI 40LFW AND THE 2004 NABI 45CLFW to ISLG right along with 2001 C40LF,they already repower their C40HF with ISLG,and their 1999 Neoplan with L10G engine.

also why did Cummins discontinue their Cummins C Gas plus for North America and still sell them to other countries?

Cummins should still sell their Cummins C Gas plus for North America,they selling it to other countries still but not North America anymore,that not fair.

Maybe the MAN engine should enter the USA and Canada Market to sell their engines as well.

[Busjack]

wow.

but why do you all hate DDS50?

there good engines and they sound good.

sure they may not be the best,but it has the best sounding right along with Cummins.

I didn't think a bus company bought an engine because "there...sound good."

I thought a bus company bought an engine because it propelled the bus while having a reasonable maintenance cost.

Clogging the particulate filters and causing maintenance problems doesn't seem to qualify.

Also, I see that some people have to find out the difference between there, they're and their, again.:P

[sw4400]

wow.

but why do you all hate DDS50?

there good engines and they sound good.

sure they may not be the best,but it has the best sounding right along with Cummins.

problary is CTA maintainance bad and Besides CTA is one of the top worst TAs.

also the DDS50 did NOT cause retirement (it did NOT make death tick sounds) to those NABIs,the NABI 60LFW had structural problems that cause the retirement, Beisde,the NABI 60LFW were worst bus built ever anyways.

Not everyone hates the Series-50, but based on what I've heard via our 5800's(now retired) and the 6000's(in process of retirement), the engine has possible serious problems. Engine squeals like the Series-50 goes through could be any number of belts and/or pulley problems... The three that I know of and come to mind are the alternator belt, cooling fan belt, and drive belt. If the alternator belt goes, the bus will probably die and require a tow to be repaired, but if the cooling fan belt and/or drive belt is the cause for this and they break, the engine could cook until it's 4,000 lbs. or siezed up useless junk. It won't take long for the engine to cook when these belts go.

Now as far as the "Death Tick" sounds you refer to from your YouTube clip, the only engines that made those sounds were our TMC RTS 4400-Series, Flxible Metro 5300-Series, and most notably to me, the 9800/1600-Series Flyer D901A Series(all were equipped with the DD6V92TA engine, except the RTS, which was equipped with the DD6V92-Non TA). I'll tell you my story of a Flyer bus with a "Death Tick" sound... I was waiting for a #80 bus one day, when along comes WB-2(and ex-Flyer D901A used as a workbus at the time) pulling into the left turn lane. When the arrow comes up, the bus starts out and the "death tick" begins, at such time a large burst of blue smoke emits from the upper left tailpipe and comes in my direction. Instantly, I can pick up the smell of motor oil being burned by this bus, and know that it's last days won't be too far from now. I only saw this bus a handful of times after this before I never saw it again.

BTW: Flxible Metro #'s 6305-6329 are equipped with a Cummins C8.3 Engine, not the DDS-50. But, just like the S-50, they also have emitted squeals from time to time while being driven(I've rode them on #9 and X9 from time to time).

[BusHunter]

I always believed the reason the belts squealed, was because they were dry and slipping. This can be fixed by spraying the belts with oil as they turn through the pulleys. 74th #6000's seem to have been notorious for these problems. I don't know if because there garage was all #6000's at one point, they simply could not keep up with the maintenance or what. I've been aboard buses with squealing belts that squealed pretty much constantly, with a few breaks now and then. The bus even seemed to be losing power on stops once. I think it was just about ready to die. You can run squealing belts for so long and then it disables the bus. Forest Glen has squealing buses but you don't hear it as often. Garages that have a small group of these like Chicago or 103rd probably have the best running ones because they can keep a better eye on 20 0r 30 buses and not run them on weekends either.

[jajuan]

Bus #6077 transfered from FG to 74th and is now running the route 67 67th/69th/71st to Ford City.

http://www.ctabustra...n=4605&route=67

I think you should have scanned the image of the Tracker view instead of giving the direct link because your link gives the up to the minute view of what's on route 67 at that instant someone clicks on the link and not the frozen instant in time you thought you were giving.

[busfan2847]

Bus #6077 transfered from FG to 74th and is now running the route 67 67th/69th/71st to Ford City.

http://www.ctabustra...n=4605&route=67

6074, 6076, 6077, 6079, 6080 all moved from FG to 74th in July

[Busjack]

i tried saving an image but, instead I got the lines.

The easiest way of doing this (someone who barely understands PCs taught me this) is that if you have a PC, have the image you want to save in the top window, then press Alt-PrtScr, open Paint or some other paint program that supports jpegs, paste the image, save it as jpg, and then use Click to Attach Files to attach it to your message.

In my experience, that saved it at the same resolution as the monitor.

I haven't had a Mac for about 12 years, but remember that the process was easier on it. This site seems to have the current instructions.

[daerah]

Although Detroit Diesel Series 50 is being phased out...I will say, I loved the sound of it while driving...sometimes the engine/exhaust would whistle loudly. That's hot. I've noticed 6005 trying to whistle louder..but its noticeable if you listen out for it. I haven't driven the NABI's 7500-7700s to see if any of their series 50 engines/exhausts whistled.

Back in California...Most of the New Flyer High Floors did, and a couple NABI low floors did.

Is that defect with the engine, or something to do with the exhaust?

[speedracer1407]

Although Detroit Diesel Series 50 is being phased out...I will say, I loved the sound of it while driving...sometimes the engine/exhaust would whistle loudly. That's hot. I've noticed 6005 trying to whistle louder..but its noticeable if you listen out for it. I haven't driven the NABI's 7500-7700s to see if any of their series 50 engines/exhausts whistled.

Back in California...Most of the New Flyer High Floors did, and a couple NABI low floors did.

Is that defect with the engine, or something to do with the exhaust?

Various engine defects can cause hissing and whistling, but what you're likely hearing is the turbocharger operating normally. Virtually all 4 stroke Diesel engines in transport applications have turbos (and have for decades). You may already know this, but a turbocharger is a centrifugal compressor that compresses the intake air, thus delivering a denser charge of air into the combustion chamber, allowing more fuel to be pumped in for more power.

It works as follows (and pardon me if you're already familiar):

Exhaust gasses exit the engine very hot, at high speed, and under high pressure. The turbo sits in the path of the exhaust, and the rushing gas blows onto a turbine, causing it to turn very fast, up to 100,000 RPM. The mechanics are exactly the same as blowing really hard on a pinwheel. After blowing through the turbine, the exhaust exits through a pipe and out the exhaust stack. The turbine, however, is connected via a shaft to a compressor. When you accelerate, the exhaust pressure builds and "spools up" the turbine, turning the shaft, which turns a compressor. Fresh intake air is routed through this compressor before reaching the engine. It's compressed, passed through an intercooler (like a radiator to cool it down), and fed into engine as cool, high-pressure air, which can "absorb" more fuel, and thus allow the engine to make more power.

The whistle you're hearing is the sound of the turbine and compressor blades whipping through the surrounding pressurized air at super high speed.

The CTA's DD50s in the 6000s, 5800s, and 7500s all had turbos that were quite loud. In particular the 5800 was just about deafening when sitting in the rear-most seats, but delightful for engineering dorks like me. (I'm not an engineer, just an engineering dork).

For some reason the turbo is harder to hear on ISM and especially ISL powered 1000s. But if you listen carefully, and you probably can't hear it from the driver's seat, ISM-powered 1000s have really quick-spooling turbos. Whereas DD50s, especially those in 6000s and 5800s, have turbos that take ages to spool, the ISM has a variable geometry turbo that restricts incoming exhaust to the turbine at low RPM when exhaust pressure is low, causing a artificially high presser on the turbine blades, causing faster spool-up.

Sorry if this was all old news for you, but it's fun stuff to know for gear-heads.

[sw4400]

(I'm not an engineer, just an engineering dork).

OT:

"Damnit, daerah, I'm a engineering dork, not an engineer!!!"

This sounds so much better in this context, and allows you to use a line made famous by the late DeForest Kelley, R.I.P!