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View Full Version : DDEC Series 60 VS 8-92 for the Novice



Coloradobus
06-20-2008, 10:15 PM
Ok, I know I am going to catch some flack, here. We are looking at a H3-40 with the 8V-92, with 5pd. We are need to get the coach down the drive of the new house, the 45 will not do it without draggin mid-body, even raising it up. Grading the drive, digging up 205 feet of "L" shaped concrete retaining wall integrated with an irrigation canal, relocating plumbing, etc, is just not practical unless we win Powerball. Remember we bought a 95 year old house with Primo water rights, with all it skisms..
The coach in question until we hear from the owner, has unknown mileage, unknown everything else.
This is purely an exercise at this point. What would be the main topic of an intelligent discussion we need to have?

Ok, Jon, Let me have it.:D I'll duck!

Joe Cannarozzi
06-20-2008, 10:39 PM
How much shorter wheel base is a 40 compared to a 45? Half of that extra length is behind the tag ain't it. So maybe 2 or 3 ft?????

No stupid questions here so: Does the 45 almost make it or not even close and are you sure a 40 will not drag?

garyde
06-20-2008, 10:52 PM
Without seeing your driveway, you may be able to modify the area which is causing the problem. If it is just the center of the driveway, you might consider saw cutting out the middle, and replacing it with Pavers with a
v-shaped contour.
How high up do your air bags rise up? Maybe that can be looked at as well. I get about 5 inches when I raise mine and it is just enough to back up my driveway off the street.

JIM CHALOUPKA
06-20-2008, 10:58 PM
Phil Cooper has a very nice 35'r, Prevo.

Short wheel base, no tag!

Coloradobus
06-20-2008, 11:17 PM
No such luck Gary, Jim, its not the hump center of the drive. Its the sidewalk at the street and then, the steep grade dropoff from the sidewalk down the driveway with the retaining wall/irrigation trough which has a good gravity drop downhill on the westside. We took a tape measure and stakes that were ride height and also on tip-toe airbag height and the tapemeasure draped over the hump.
The 40ft wheelbase is 23ft3 in. Our "H"'s wheelbase is 26ft3in. Joe,the 3 feet makes a big difference at ride height, extending the airbags all the way up would clear it for sure. To add to the insult, the water meter is dead center had highest spot of the hump before it drops down the driveway
The hump in the driveway is parrellel to the sidewalk at the street.:(

My biggest interest is what diffierences are we going to see/feel with an 8V-92 vs Series 60.??( which we have had 3 different busses with 60's in them) I know the mileage is not as good.

Jerry Winchester
06-20-2008, 11:21 PM
Jim,

Obviously they can't read. You didn't ask how to get the coach up the drive, but about the engine.

I would want to know about the history of the engine. How long it has been sitting or how infrequently it has been used. I would want to download the codes and ask if had ever been hot. You might not get a good answer and they might have erased the codes, but you still have to ask.

How much oil is it using. It will use some, but if it has excess blowby or oil leaks, it may need some help.

Have they been using the "correct" oil in it or does it have multi weight?

When was the last time the coolant and radiator was serviced. You might take some test strips and just check it.

If it hasn't been hot and has had the right oil in it, chances are it will run for a long time. If it has been abused or rebuilt because of a driver error, be careful.

tdelorme
06-21-2008, 07:50 AM
Jim, our coach has an 8V92 and I ask the same questions before we bought it. Like Jerry says, get a code reader to check the engine's history. If the codes have been erased and the computer reset, I would walk. I got a well cared for 8V and it does not leak oil, or use much oil. Maybe 1/2 gallon in 1000 miles. The BIG difference in an 8V with a 5 speed, is the 8V has a much slower rate of acceleration. You get used to it, but at first I thought there was something wrong with the coach. When you start off, you floor it and nothing happens for a second or so. Then she starts to roll slowly at first and your thinking "come on baby lets go." Then at about 5MPH the turbos kick in and off you go. It takes awhile to get used to it. At speed there is little or no difference other than you will get about 2 1/5 miles per gallon less than a Series 60. I can push the bus and run at 75, but she really like to cruise at about 65. I've tried slowing down to 60 or so, but I always seem to creep back up a bit to avoid being run over. You hear stories about everyone slowing down, but it ain't happened in Texas so far.

truk4u
06-21-2008, 08:34 AM
Jim & Chris,

Mel and Jdub covered it pretty good and I'm sure Jon will be in here. I see no problem with an 8V as long as it hasn't been cooked. Take those precautions and you should be OK. There are still lots of places out there that can work on them. I was at Prevost Nashville a few weeks ago and the Tech had only been working there about 6 weeks. He came over from Detroit after being there 16 years and said they will now do overhauls in-house instead of sending them to DD. I asked him about the 8V's and he said he would take an 8V any day to overhaul instead of a 60. My point is, they can still be worked on and are much easier in some respect than the 60.

I'll go out on a limb here as well and don't see much of a downside to owning a 40' H. There are some buys out there for sure. Your probably going to keep it for a while, so maybe the market will be back up when it's time to unload it.

Keep us posted....

Joe Cannarozzi
06-21-2008, 08:58 AM
JUB what, we can post anything anywhere but we can't answer a question with a question? He said DOWN the drive not up it. Besides you do not need to know how to read anymore, I see it all the time.

Excuse me Jim but the first thing I though of was what kind of info can I give a guy like this that he doesn't already know.

Being in the mountains all the time the rear-end ratio would be important to me.

Ours had a 3.32 and it did not turn 1 rpm over 2150 and also did not shift into high gear until 60 mph at the earliest. She would be able to run out the speedo.

There are other buses I have driven, Tullys; and know of, AJ's and Bills that would turn 2400 rpm shift into final gear at 55 and be turning 2400 at 75 mph, flat out.

garyde
06-21-2008, 09:50 AM
If you can no build a better driveway or a 2nd driveway, the choice might be to find storage off site.

MangoMike
06-21-2008, 09:55 AM
Jim,

I'm with Gary. The H3 you have now is gorgeous with a unique layout. I would be looking for that offsite bus barn and just go with the inconvience of being offsite.

Mike

Jon Wehrenberg
06-21-2008, 10:06 AM
I like the 8V92, and the only downside from my perspective is its thirst for fuel relative to the Series 60.

They will run side by side, although due to the World transmission I think the Series 60 comes off the line quicker. Once spooled up the 8V92 will do just as well. You may notice some sluggishness at your altitude on an 8V92, but I had some with my Series 60 when we recently went west, but not as noticable.

Ditto the comments about checking the codes, and especially do a real close inspection of the radiator and cooling system. A lot of folks ignored the maintenance requirements on the coolant and that engine seems to cause a problem with occlusion in the radiator. An over temp on that engine is an expensive oops. If you want to protect yourself mentally add $20,000 to the purchase price and if the cost still seems OK that should cover an in-frame rebuild and a new recored radiator if required.

My real concern that you guys need to determine however is the Liberty generator baffle hangs down at about the midpoint on the driver side and whatever clearance the shorter wheelbase provides, that might take away. I made a template to check my driveway slope transitions and I added the baffle dimensions to it to verify my original coach could make the transitions without changing from the ride height. Going to a 45 I had to raise the front fully to clear the baffle so since you are going the reverse direction with coach size you may be OK but verify it. If the baffle does interfere there are 3 options....don't get a Liberty, make the baffle from mud flap material so it will crush and return to the needed shape, or redesign the baffle for easy removal or lower profile.

Coloradobus
06-21-2008, 10:52 AM
JBUD,

the coach in question has a matching Featherlite Trailer. This problably a coach to definitely check the codes, to make sure the P.O didn't cook it towing with a car and golf cart and harley's in the trailer.
Are the 8V's prone any easier to overheat than the DDC. Ours very rarely hits 210 lugging on a grade before the fan kicks in and cools it to below 195.
There is a Custom Coach H3-40 on Phil Cooper's site with a reported Penske re-build 8V yielding 560hp.
Speaking of gear ratios, do you supposed Prevost will have build docs to indicate what the ratio is, or do we need to spin the wheels in the air and count the driveshaft revolutions?

Thanks for the input.

We already store the 'H"3-45 over at our shop/office, but would like to keep it in the new barn next to the house. When we lived at the shop/office it was very convenient to just go 50 feet to the barn and work on the coach.
It also made loading for a trip easy.. Now we have to make multiple car trips to load the coach.

Jon Wehrenberg
06-21-2008, 02:51 PM
The 8V92 is supposed to run cooler than the Series 60. Ours ran an indicated 180 average and would fluctuate between 175 and 185 due to the cycling of the thermostat and radiator shutters. Those temps on both engines are design temps and in the case of the Series 60 they have to do with the emissions requirements.

On a steep long hill I used to climb in 4th at 55 which for my gearing was max RPM and the temp would climb to 195 and stabilize there. When my radiator was starting to become less efficient due to cooling fins literally corroded off from running in the salt up north the temps would stabilize at ever increasing values and when it finally hit 205 going up the same hill I could take at 195 degrees previously I had the radiator recored.

Towing a heavy trailer up hills is the equivalent of increasing the angle of the hills. The bus has to work harder and harder. If the owner allowed the temps to get high that could be an issue. What my concern would be however is the condition of the transmission. Those transmissions were not intended to be dragging around a 45,000 pound bus plus 20,000 pounds of trailer. I would also have some concerns with the effect on the rear frame and engine cradle of the bus. Unless the previous owner had Prevost install the mods for towing a heavier vehicle anything over 10,000 pounds or a tongue weight of 1000 pounds exceeds their limits and cause some structural issues.

Kevin is more up to speed on what is required to pull a heavy trailer than I am and I hope he picks up on this thread.

tpr
06-27-2008, 08:25 PM
I was wondering if anybody has any input about the XL2 with 430 horsepower. I've been talking to a dealer with a great 2005 coach that would suit me fine but I'm afraid of the horsepower issue. My 40 foot XL series 60 goes like a rocket with 470 hp. How do you think the 40 less horses effects pulling, top speed and heavy traffic acceleration? I'm in Penna. to go West I always have to go over mountains. What do you think?

Kevin Erion
06-27-2008, 08:43 PM
I would look into the possibility of increasing the HP to 475 or 500, should be easy. What year is the shell?

Petervs
06-27-2008, 09:50 PM
One of the big differences is the 8V92 has a one speed cooling fan, and the series 60 has a two speed unit. This helps significantly keeping the engine cool on a grade. Overheat the 8V one time and it is overhaul time.

AND

Even though fuel is but a small part of ownership cost, there really is a difference between 6 MPG and 7.5 MPG. 10,000 miles per year on an 8V would be $10,000 for fuel at $6 per gallon but only $8000 with a series 60. You are spending 25% more for fuel with the old engine no matter what a gallon costs. You will feel the pain every time you stop at the pump.

So, there is no advantage to the 8V, it just happens to be installed in the older coaches. They have not been installed for 15 years now, eventually it will be hard to find a service technician who knows how to work on them. There are essentially no trucks in use with them any more, just stationary power units, boats, and a some Prevost coaches. And there is no sensible way to put a modern engine in an older coach, the economics do not make sense for that.

I say stay with the modern engine.

As for the Featherlite trailer, it is interesting they chose the name Featherlite. Those trailers are anything but light weight! I bet they are over 10,000 pounds empty, and while the coach can certainly pull it, you are not doing fuel economy, cooling systems, brakes, or transmissions any favors by adding the loads, all those components will show more wear and tear compared to not pulling that heavy trailer.

My $0.02 opinion is yours free here!

Joe Cannarozzi
06-28-2008, 01:18 PM
TPR

That 2005 with a 430hp is a 60 series straight-6 with a little less hp or a 8-V?

I am assuming it is a 60 series based on the year. If so you can have it turned up to whatever computer parameters and cooling capacity will allow without even changing any parts. A little more timing and a different pump setting all easily done by any competent mechanic.

IMO I would try it first. That lower HP may not be noticeable and the motor will love you for it.

What was the last production year for Prevost with the 8-V? I did not think it was possible to put a 60 series in a 40fter????

Alek&Lucia
06-28-2008, 01:40 PM
Joe,

Our '96 40XL Country Coach had Series 60 475HP

Alek

Jon Wehrenberg
06-28-2008, 02:17 PM
Upping the HP is easy. Being able to use the HP is not always as easy. The key to any HP increase is the ability to get rid of the heat produced. Prevost has to jump through certain hoops every time they install more HP in a coach. Detroit has to approve the engine cooling system because as HP goes up so does the amount of heat that needs to be returned to the atmosphere.

If the cooling system cannot handle an additional 40 or 45 HP, the engine computer will automatically roll back the HP produced by the engine to prevent overheating and damge due to overheating.

Hill climbing is as much a function of engine power management such as downshifting at the right time, building up a little speed before beginning an ascent, and doing little things like temporarily reducing loads such as AC units so the engine output is sent to the drive wheels as it is a function of available HP.

I doubt if any of us uses the HP we have available 1% of the time. The rest of the time we are cruising or descending.

tpr
06-28-2008, 08:08 PM
Joe,
My 40 foot XL is a 1995 shell with a 1996 Angola conversion. It has a series 60 and with the weight of the coach it jumps at acceleration. The 2005 is on a 2004 shell and i'm afraid if the hp is turned up it will indeed overheat as Jon suggested. My previous coach was an MCI with an 8V92 TA and heated up constantly making for a very unsettling trip each time out. Living in the congested northeast a 40 makes sense but I will start looking for a suitable 45 and join the big boys.

Ray Davis
06-28-2008, 10:24 PM
I have a good friend who is a regional specialist for Detroit Diesel (I guess which now owned by Freightliner?)

He suggested when I purchased my 93 CC which was a 500hp 8V92, that I turn it down to 450hp. He said it would run cooler, and last longer if I did.

Although it wasn't fast off the line, it carried with the big dogs without problem. I would beat some S60's up the Cajon Pass leaving Southern CA.

And I will admit, there's nothing like the 8V sound!!!

Ray

BrianE
06-28-2008, 10:34 PM
My experience is similar to Ray's. When we had our 8V overhauled at Southern Oregon Diesel three years ago, it was recommended to adjust the hp from 500 to 450. Haven't missed the ponies a bit and it runs smooth and cool.

Joe Cannarozzi
06-29-2008, 05:55 AM
I am still assuming what engine is in the 2005 but as I said previously and as others have subsequently suggested I would try it first you might not notice and it will love you for it, with the latter part of that eluding to temp. issues.

If you do decide to turn it up and if it is a 60 series I do not see why you could not turn it up to the standard rating without fear of temp. issues? I think 435hp is standard setting for the 8-V, that's what ours was and it always ran cool.

What was the last production year for Prevost with the 8-V?

Jon Wehrenberg
06-29-2008, 07:31 AM
If my memory is correct the 45 foot Prevost shells when first introduced (chassis year 1994?) had the Series 60 and the five speed transmission. The 40 footer continued with the 8V92 so there was some overlap.

Because of the length of the five speed vs the six speed it was not until the six speed became available to Prevost that the 40 foot coaches could have the Series 60 installed because that engine was longer than the 8V92 and it needed to be mated with the shorter 6 speed. I believe they were late 1994 or maybe 1995 shells when the 40 footer had the S60.

Anybody with these model years correct me if my dates are wrong.

truk4u
06-29-2008, 09:08 AM
Joe - My 97 Marathon was a 60. There's lots of 40's out there with the 60.

Joe Cannarozzi
06-29-2008, 11:05 AM
Originally TPR was wondering about a 2005 with 430hp engine. Some assumed, with good reason, because of that particular HP and where the thread it is posted in he was referring to an 8-V.

I doubt if a 2005 XL2 would have this engine but I could be wrong. TPR has not said specifically as of yet.

Needless to say it has tweaked my curiosity about a couple of things. What was the LAST year the 8-V was used in a Prevost in any configuration? What is the "normal" or maximum HP available for the 60 Series in a Prevost and would anyone disagree that it would be safe to turn one up to that point without cooling issues?

TPR our semi was a 350HP in a world of 400 thru 600 hp stuff. Compared to the 500hp engines and bigger the difference in acceleration was quite embarrassing. However when along side a 400 with only 50 more HP the difference loaded pulling a hill was equal to that of a man slowly walking, or strolling.