New PREVOST at Perry with Volvo engine.
Appears to have 4 automotive style alternators and a new radiator fan drive.
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New PREVOST at Perry with Volvo engine.
Appears to have 4 automotive style alternators and a new radiator fan drive.
Well, I am looking at the belts and pulleys and wondering what happens if...........
Ken:
I agree regarding the belts. Why four alternators? The KISS method was not applied here ! Makes you wonder about the rest of the engine change.
I count 8 belts. I can't see if the fan is belt or gear driven.
The number of alternators could be due to a couple of reasons. First, the big 50DN that is used on a lot of our coaches is a Delco product, (GM was at one time the parent company) used on a Detroit Diesel (GM was at one time the parent company) and is not likely going to be found on a Volvo.
But my guess is the alternators are chassis and house, and without getting into it is its difficult to determine which goes where. The bus does not appear to have OTR so it is possible the converter may have three alternators so the roof or Cruise Airs can run off the inverters.
The whole installation looks like a hot mess.
Does not look like it would be fun to work on. Notice the change to a tube type structure supporting the engine, likely an attempt to shave weight. Also note what appears to be an air bellows supporting the engine. Seems like a good idea to isolate vibrations.
I wonder how that frame structure will work with some of the heavy stacker trailers now being pulled?
Anyone notice the lack of chassis batteries???? Moved due to weight distribution? I would like to have an engineering presentation on what changes have been made and why.
Looks like the big green pulley is turning a shaft for the fan, similar to all the previous Prevosts.
What Jerry said!Quote:
Originally Posted by Jerry Winchester
The belts do seem to be complicated,the series 60 is a antiquated design for today's emission rules,the Volvo is a much more up to date design and it should perform better with the DEF even though it is about 75 cubic inches less than the 14 liter series 60.I hope that the Volvo gets better fuel mileage,it will have a 4.10 rear gear compared to the 4.56 that was in the DD coaches.Volvo wants the engine at 1400 RPM at cruise and this should help mileage but it might also hurt performance.I have been told that the torque and especially the horse power curves happen much earlier on the Volvo compared to the series 60.
I'm with you Ken.Quote:
Originally Posted by Kenneth Brewer
Thank you.Quote:
Originally Posted by Jerry Winchester
If a belt let go.......
Sorry, but I don't think anyone would call this an 'engineered' integrated approach that is in the neighborhood of reasonable expectation, even for a first year(?) introduction, even without three of the four alternators. Certainly not an improvement, in my view, and if I were a shop manager, I would charge a good deal more on labor for anything associated with this mess, counting pulleys, belts, and shafts. if I were the engineering director, or being evaluated, and had to defend this as an improvement or advancement.....
Definitely NOT MY CUP OF TEA, makes me like my bus even more!!!
JIM ;)
I will return to the PREVOST display tomorrow and see what additional information and pictures I can get before being asked to leave.
John,
Was that small tank on the passenger side for the UREA fluid?
I agree with you Jim. John, was there any mention of fuel mileage with this engine? I've heard that around 3.5mpg is the EPA rating. When I was at Prevost JAX last year the only new seated coaches on the lot were Volvo brand with Volvo power plants. Any mention of transmission? ZF or Allison?
Are these pictures of a Conversion Coach, Entertainer Coach, Passenger Coach, H3-45 or XLII? I would assume the Convertor Coaches will look different based upon OTR, Coach and House Batteries, alternator, et.
The Prevost brochure and price sheet only shows the Allison as the available transmission.
The shell on disply here in Perry is going to Millenium for conversion.Quote:
Originally Posted by garyde
I know that all the engine makers have been trying to get the engine to run slower at cruise speed. We ordered our last trucks to run just under 1400 RPM at 65 MPH (we limited them to that) and that was just at the point that Caterpillar said was the best for fuel economy. When I was at Prevost TN last Sept. I saw a new bus with the Volvo and I asked the tech working on my bus what he knew about them..he said that the torque was better even though the HP was less. He said it was supposed to perform better than the 60 Series it is replacing. I guess we will have to wait for someone in the group to get one to see if he was blowing smoke or not. The one I saw did NOT have that complicated belt / alternator setup on it.Quote:
Originally Posted by jack14r
The propaganda I've seen claims power and fuel mileage will be up over Volvo's PRE-UREA INJECTED ENGINE because the engine can now be tuned to be run more efficiently (dirty) with after clean-up in exhaust. I have no idea how pre urea Volvo's stack up against late model DD60's.
I'm not an expert on emissions, or what constitutes clean exhaust compared to dirty exhaust. I fail to see the logic in taking a diesel engine (SS60, DDEC III) that could deliver 8.0 MPG in our buses and in the process of making the exhaust cleaner (SS60 DDEC IV and above)make it burn more diesel.
In 1968 or thereabouts cars were forced to meet emission standards and it is only in the last decade that we are seeing not only clean engines, but engines with more power despite getting fantastic mileage and long life. During that 30 year time frame between when the standards were introduced and the real start of clean engines with real power our cars were strangled with air pumps and all sorts of interim measures that robbed power and increased fuel consumption.
I think the single greatest technological change that made our engines what they are today is the widespread use of very sophisticated computerization that can literally deliver the correct fuel/air mixture on every compbustion stroke.
I don't doubt diesels can make the same progress, but I think what we are seeing today is the repeat of the early emissions gas powered engines where add on features are required to meet the standards. Maybe 10 or 20 years from now diesel engines will meet the standards without any external devices or power robbing controls, but until we get there I think we have seen the last of good mileage and relative simplicity in the engines. I just wonder how truckers are going to impact what is happening. Right now truckers have access to all sorts of program mods for DDEC to give substantial power increases and unless and until the current crop of engines is built so they cannot be modified I think we can expect to see owners start modifying their engines. In the 90's a lot of Prevost owners were bumping up the HP in their 8V92 engines and we may be seeing a repeat of that.
But in the meantime I am going to try to figure out how less MPG equals good. It must be the tree huggers have one set of needs and they are in confict with those who want energy independence. The tree huggers won this round.
It is not just the lower MPG, but also a decrease in oil change mileage intervals and the associated waste from those. I couldn't understand any of this either...go down in mileage, change oil more often and often times have emission related issues all in the guise of being "clean". Also, engine life has gone way down in the quest for "clean". Before the EPA got their fingers more deeply into diesel emissions, we could regularly run Caterpillar 3406 engines between 800,000 to 1,000,000 with little expense or work other than maybe rolling in a set of bearings and change out the fuel nozzles..things that were not terribly expensive. Each time the EPA had a hissy and mandated more controls, miles to complete overhaul went down and expenses went up. Granted, this was the time frame that also brought us electronic engine controls and the good things associated with them, but the overall cost has still not come down to where it used to be in regards to maintenance.
That is one reason why you sometimes see so many late model trucks sitting on lots...many people just lease or trade and turn them after 2 or 3 years and do virtually no maintenance. The exception to this trend was the delays many made in purchases waiting to see how bad the 2007 and especially the 2010 emission changes were going to be...DPF and Urea being the big ticket items that come to mind.
This kind of reminds me of the time when the government was starting to mandate passive seat restraints and air bags in cars.
The auto manufacturers purposely designed, built and sold those horrible shoulder seat belts that were attached to the door and (hopefully) retracted when you closed the door. They knew the public would complain and complain loudly. This was an attempt by the auto makers to get the public to pressure Big Brother into delaying the required start dates for air bags.
This is NOT speculation as this sorry episode has been well documented. The auto industry was trying to save money and push regulation off as far as they could. The additional expense of adding air bags was considerable.
So, it is not beyond possible that engine manufacturers are playing similar games regarding emissions, and the cost of compliance, too.
Additional photos from Perry.
There are a total of 4 belts but it looks like a lot more.
Coach has not been deliverd to converter.
Other options for number and type of alternators avaliable.
This one was at the request of "Marithon"
Is the top photo of the driver's AC compressor on the extreme left? Is the air compressor gear or belt driven (don't see this at all right now)? Just curious about what I see in the photos. At the moment I think Jon is right, 8 belts; 4 separate pulleys on the main crank, one of which is a double belt and the other 3 are serpentine, and two pulleys on a separate shaft (driven by the double on the main) to the right, one of which is a double belt. Total; eight.(?).
Belt label from engine compartment
Reminds me of an Allis Chalmers Combine--- an old one that we pulled with a "M"Farmall.
I'll stand by my count of 8 belts. The diagram does not reflect all the accessories or count the two dual belt drives.
Regardless that's still a complex set up.
You are correct Jon. I simply counted the belts shown on the diagram, I hate it when that happens.
John,
Thanks for the photos. Fascinating!