Engines

[easdsa]

As we research, I've discovered that many of the bus conversions (Wanderlodge, etc.) seem to have Detroit Diesel engines in them, while the production DP rigs (Winnebago, HR, etc.) seem to have either Cat or Cummins engines. To be fair, there is quite an age difference between the bus and DP rigs. Is that the main reason for the engine difference, or is there more to it?

I don't want to start an engine war here, just wondering why the difference.

[Route 66]

Perhaps those old DD engines were too heavy for anything smaller than a bus.

IIRC, Prevost was the last bus to use DD and they switched to Volvo engines since DD no longer makes on-highway engines.

[rops]

Detroit Diesels are still being made. They do not make them in 2 cycle versions anymore for the highway trade. Simply type in detroitdiesel.com in your browser and you can read all about them. They are among the most popular engines among hardcore truck users. The old 2 cycle versions were lighter in weight than their competitors, not heavier.
The engines being used in most motor homes are not used in class eight trucks. They are smaller, lighter and have less torque than most class eight truck engines.

rops

[wingman8]

Originally Posted by route 66

perhaps those old dd engines were too heavy for anything smaller than a bus.

Iirc, prevost was the last bus to use dd and they switched to volvo engines since dd no longer makes on-highway engines.

i would think that since volvo owns prevost they would use their own engine rather than someone else. What do you think?

[Mike Canter]

Let me add something here. The DD series 60 was used as the main engine in the Prevost then the Series 60 was dropped by Detroit because of the required emission changes by the Federal Government. Detroit also makes and sells Mercedes Benz diesel engines and Prevost wanted to switch the the MB motor but MB came out and said that the MB engines can only be put in a bus that was made by MB. Bad decision. This forced Prevost to switch to the Volvo engine then MB realized their mistake and tried to get Prevost to switch back but it was not going to happen.

As far as putting the Detroit Series 60 into other MHs, Monaco put it in the Signature, the Navigator and the Executive and maybe the Dynasty (not sure on the last) and it is a great motor. The problem is that it is a big motor and smaller MHs can't pull the weight and it requires the Allison 4000 transmission. So now we are talking big bucks here to put that kind of motor is a smaller MH. The other thing is how many MHs require over 525 hp and 1650 ft lbs of torque?

[targaboat]

They all do to maintain 60 mph in the mountain passes.

[Mike Canter]

Even with 525 hp and 1650 ft/lbs I don't have the guts to do 60 mph on a 6%+ grade. I find keeping the Detroit Series 60 at 1800 rpm in 4th gear at 48 mph the most comfortable speed that doesn't scare the DW to death.

[bucks2]

The older Prevosts used the 8V92 Detroit Diesel 2 stroke, rattly bang noisy engine. Horsepower could be "adjusted" depending on which injectors you used. (and of course tweaking the blowers) The big downfall of the 8V's was the need to put a drip pan underneath to collect the oil and pour back into the engine each day. They were notorious leakers. Screaming Detroits didn't get their nickname for nothing.

Prevost started using the Detroit 60 series in mid and late 90's models.

[targaboat]

The old two cycle engines run faster than the current crop of engines. Therefore, they should be run above 2000 rpm on the grade climb. Otherwise they will tend to get too hot for the coolant flow is not were it should be to adequately cool the engine.

[173dave]

So, can we assume the new, 2007 + emissions stuff is not good for the engines or the MPG?

[targaboat]

Why do you care? You will never wear any of the diesels out. This whole thread is sort of like discussing the the trees in the forest. We have technology changes on top of environmental regulations which makes it very difficult to make any single minded conclusions like the future durability of the new engines resulting from the emission add ons.

[wa8yxm]

Not to disparage any engine maker.. But at one point the Detroit Diesel engine had a reputation for doing one thing better than any other engine (Spitting/leaking/burning oil) then the made a few changes and developed another "Best at" reputation... Passing fuel stations. (Best MPG of any engine in the business.. My brother's semi, deadheading, got better MPG than my CAR if you can believe that.. And I do)

For a fact the engine that makes the world go round is a Detroit Diesel.

(That's what they use to run the generators at the North Pole Research Station)

Note other than MPG, this says NOTHING about other engines. And I'm not sure if TODAY's DD's' are as good at fuel economy.

[Robot9000]

Detroit Diesel made a bunch of different engines: 2 strokes, off road, Military, on road, gen set, marine,etc. Roger Penske bought them in the late 80's and got their quality issues taken care of and got the development of the Series 60 going. The Series 60 was their best seller and slowly they stopped production of engines that didn't sell so well or were being phased out due to emission requirments (2 strokes, bus, etc). They were partnered with MTU (Daimler) for years and Penske sold DDC to them. Daimler also owns Thomas Built buses, Freighliner, and Western Star.

The late 2000's saw a lot of consolidation in the trucking industry and Detroit Diesel being part of Freightliner was part of that. They slowly rebranded and changed their lineup and I think getting out of the RV's may have been a part of that. They were big in marine power, but not so much in RV's by comparison. Semi trucks and gen sets were by far their bread and butter followed by military, marine and large specialty engines.

BTW, I worked there for 11 years

[JohnRR]

Originally Posted by Robot9000

Thank you for the information.