Hey guys, browsing prevosts and noticing most of them either have a 8v92 or 60 series. Is the 60 series also a Detroit? Also what are pros and cons of both of these engines? Thanks!
60 series is a four stroke Detroit but not near as cool as the two stroke 8V92. I believe in 1987 DD added all the electronic stuff many have problems with.
Bruce
Oh and one more question. How many miles should these motors last? I guess a better question is, at how many miles should you not purchase one?
I've been told that it's much easier to find mechanics to work on the 60 series? What about fuel mileage?
I believe you'll be able to find a mechanic in most areas, they made a lot of them. A 60 series any Detroit Dealer will have parts and expertise. As far as mileage, couldn't say. Mine is pre electronic stuff and on a good day gets up to 7 mpg but most of the time 4 to 6 depending on terrain. Comparable to a truck and a large fifth wheel.
Bruce
I'm part of the tiny minority on this forum who are not fans of the 2 stroke DD. One way to think of the difference in the two engines you mention is 1930s technology vs. 1990s technology. A lot changed in this world during those 60 years.
The 2 strokes produce considerable torque for their displacement, but they are among the dirtiest burning engines in existence. The 60 series is one of the cleanest and most fuel efficient engines ever built. Many of the 60s were built before federal EGR mandates, and that is a plus.
I will never fully understand the deep-seated paranoia about "electronic stuff." Hardly anyone on this forum does not depend daily on some vehicle with multiple computers and electronic systems, but I hear no one talking about trading their cars and pickups for 70s models with carburetors and ignition points. Electronic controls and sensors for diesel engines and automatic transmissions represent a major improvement in bus efficiency, reliability and diagnosis. Even the 2 strokes and Allisons made after 1986 have DDEC and ATEC.
Everyone is entitled to their opinion, and you will certainly read many that run opposite of mine. So be it. I lived for nine years with a 6v92TA DD (2 stroke), and I will never own another. Our current bus has a four stroke 40 Series DD (8.7 liter) concerning which I can wax eloquent.
Two stroke lovers carry on about the "sound" and the "feel", and I respect visceral attachment to technology. Everyone should own and use what pleases them. I, on the other hand, am attached to the fact that a 60 series operates so efficiently that over-the-road trucks running 60s usually have to have a separate system to heat the cab. I love the sound of dollars NOT being spent on fuel and the smell of air bearing significantly fewer emissions, but that's just me.
In the end, you pays yer money and takes yer choice.
Best of luck,
Jim
I vote with Jim H. I have had both. I have put about 250,000 miles on my 8V92 before I sold the bus, and I have a similar amount of experience with the Series 60, both a 12.7 and a 14.0.
No engine on the planet sounds as sweet as an 8V92. It is an easy engine to work on when installed in a Prevost. But it is not real economical to own. My lifetime mileage in a DDEC I 8V92 was 5.6 MPG in a 40,000 pound coach. My 12.7L Series 60 in a 46,000 pound coach was an 8.0 MPG engine until the fuel sulfur content was messed with and it went to a 7.5 MPG engine. My 14.0 liter engine in a 53,000 pound coach is a 6.0 MPG coach, but it has an EGR engine.
The Series 60 installations will only allow limited engine access with serious work having to be done on an engine that is removed from the coach. Bot Series 60 engines are excellent. The do not use oil, they have been very reliable, and if they needed work any Detroit shop has the expertise that is not always available for the 8V92.
If you are buying a converter coach that started life as a motorhome it is unlikely you are going to need to think about engine rebuilds or service unless it has a lot more than average use. All bets are off on a seated coach conversion. In fact with the market for older used coaches ad deep in the dumper as it is, it only makes sense to buy an older Prevost professionally converted coach because prices are so low you cannot buy an old seated coach with long engine life, plus all the stuff to make the conversion for what some conversions are now selling. Some that look decent are in the sub $50,000 range in fact. Those are going to be an 8V92.
I like my Series 60 even if does have a computer. At this point I don't think I would want a 2 stroke bus if you gave it to me. If it does need service nearly every town has someone who can work on a Series 60. Not so much with a two stroke.
Cars have been electronically controlled for 20 plus years now. I doubt many of you drive cars that don't have electronic fuel injection.
LOL electronics are not the only problem with engines but you are lucky if you have a non EGR engine.
Fuel mileage is not that much difference all the 14L DD I have been around are 5 at tops @ 70 mph.Mine coming from OK to AZ was 4.8 mpg a H series with a 515hp 14L Detroit
I looked at a few H series Prevost with the 11.1 series 60 engine those were a joke the outfit had 10 of the H's with 11.1's they were trying to rid their self of, so you buy what you like they all have problems
Being old and near crazy, I do love the 2 strokes, BUT their time is about over. Today the ECM (computer) is the way to go, the earlier ones prior to the EGR is good. I wound up with the Cummins ISM500, was the ISM450 pre EGR 2001 model, had upgraded to the ISM500 + rating, being a Cummins dealer, some things are possible ;D, Point; I now prefer the reliability, smoothness and yes power of the ECM setup along with the Allison 4000R into a 3.91 rear, a happy setup. Note, the ISM 11L is the smallest engine Cummins rates as Heavy Duty.
Dave M
My current 14L Series 60 is an EGR engine. 515 HP. My first step was to add the Ugly Fix which fools the engine so the EGR will not function. My mileage went from 5.9 to about 6.1. Then the ECM was programmed to change the EGR "on" to 3200 RPM, and the EGR "off" at 3600 RPM. Obviously that means the EGR is not going to function. At the same time I plugged the exhaust path just downstream from the EGR cooler so no exhaust can enter the intake manifold. After doing that the mileage went to 6.2 MPG.
After several thousand miles of driving the mileage started to creep up. Apparently the exhaust gas entering the intake manifold soots up the valves and maybe the cylinders so it appears the engine is cleaning itself up which is now reflected in approximately 6.4 to 6.5 MPG. My next project is to get with one of the members of this forum and strip my engine of the EGR related components, including the V pod, heat exchanger, intake manifold, exhaust manifold and turbo and replace the manifolds with non-EGR manifolds and a larger single speed turbo. I know another owner who has made that mod and his 14L Series 60 has gained about 1 MPG over his previous mileage.
My point is later engines were not designed for mileage or performance. They were designed to meet EPA emission standards and when we rid the engines of the garbage that was hung on to meet the standards and get back to a pure Series 60 we have both power and performance. I won't go back to a two stroke although I really do like their sound.
BTW, I am 53,000 lbs, and typically tow and H2 Hummer at 6700 pounds, but I cannot keep up with Clifford. I drive about 62 MPH.
LOL it is either drive 70 to 80 mph on I 10 in west Tx or get run over Jon
We get 8 MPG with our 60 pre EGR, 65 to 70 MPH 50,000 total including toad. Now in the mountains about 6 MPG. Total miles on coach is 110,000, DDEC 111
I know the feeling. I have a 6V92 in my MC-9 and a Series 60 in my Eagle. I definitely like the sound of the 2-stroke much better. Even more than the 6V92, I liked the sound of the 8V92 I had in my MC-7 even better. I used to run heavy equipment and one of my favorite sounds was when I started my dad's D4 dozer on gas and after it ran for a minute or so depending on the ambient temperature, and then shutting off the gas supply and pushing the diesel throttle forward as it switched over from gas to diesel. The sound of that old diesel starting up and watching the smoke rings come out of the exhaust stack was awesome.
Someday before I take the Eagle on the road much, I plan on finding someone with an 8V92 and putting my tape recorder near the 5" exhaust pipe and have him take off down the road and go up and down the mountains for about a 45 minutes then copy it onto my 8-Track tape player. Then when I fire up the Series 60 to head out on a trip, rather than playing "On the Road Again" by Willie like I usually do, I will turn on my 8-track player and turn up the volume on the inside and outside speakers in the engine compartment and everyone will think I have an 8V92 in my Eagle and it will be music to my ears.
Quote from: Gary Hatt - Publisher BCM on July 22, 2015, 05:35:22 PM
I will turn on my 8-track player and turn up the volume on the inside and outside speakers in the engine compartment and everyone will think I have an 8V92 in my Eagle....
I KNEW 8-track tape was gonna make a comeback! I wonder if I still have Iron Butterfly's In-A-Gadda-Da-Vida. That drum solo sounds like my old two-stroke pulling hard. Or trying to.
Jim
I own both a 6v92 and an 8v92 coach. I much prefer the sound of the 8v92. Just sounds so sweet. As for the 60 series, I'd love one, but I can't be led to believe they are smoother. The one I rode in vibrated the whole coach at idle. Loud as heck too. Was in a j4500. My 6 and 8v92's idle smooth as silk and no vibrations in the coach.
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Scott I have heard this before but can't understand it, we can't hardy hear the 60 running at the front and mid coach and don't have any vibration. I have 2 strokes, and cats and can't say the same for them. The 2 strokes do sound nice tho, I agree on that
I wonder if you could feel vibration from ANY engine in an XL.
Lol....maybe the extra 5 feet helps? I don't know, I just recently though experienced a 60 series in a new j4500 and Heather and I both could not believe the noise and vibration when he started that thing. Maybe it smooths out once it's running beyond idle rpm?
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My 40 foot XL with the 8V92 had both noise and vibration. I knew that because when I got my 45 foot XL with the series 60 I was amazed at how little noise and vibration compared to the previous bus. The XLII is at a whole different level. Unless I am in the garage when I start the engine I cannot hear it, and the only way I know it is running is because I can sense it. I don't know if it is a combination of sound and vibration, but regardless they are so low it is hard to tell it is running. I think it all has to do with insulation on the part of Prevost and the converter as well as vibration isolation on the engine. The noisiest part of the ride when going down the road is the AC fan at the dash.
Yes Jon exactly, mine is the XL (the best I think 😊). When we're on the road Jr sleeps and watches TV in the rear bedroom and it is not a problem, sure you can hear it since the engine is just a couple of feet under you but it really isn't that bad.
LOL the 60 series will shake at idle the lead sheet that runs from the rear to front on a Prevost hide a bunch of it plus the $$$ marine engine mounts they used later.
IMO there was nothing worse than a series 60 in the early Prevost for vibration
Most of us have 2 strokes in our buses because of their age: 70s and 80s. They are still great engines and we love them ( I do) for the nostalgic factor: nice sound, that is what I used to drive way back then, etc. They require more maintenance and attention than modern engines. You have to be a half a mechanic yourself to keep them going, because most diesel shops now do not work on them anymore.
Us bus nut hobbyists are entering a new era recently, with 4 stroke powered coaches becoming more affordable on the used market. Now you can get a 1990s and 2000s seated bus for less than 40000 or $50000. And even used factory conversions with 4 strokes are quite affordable for the average bus nut frequenting these forum.
The Detroit S60 is a great engine. Even though it is already obsolete, it is still well supported with parts and service. Any diesel shop is familiar with it and will fix it, because almost every truck and bus on the highway in the 90s and 2000s had a S60 then.
I ran one in the hockey team's 102D3. It was a 1995, pre EGR, with a 7 speed Eaton/Fuller manual. Lots of torque between 1200 and 2000 rpm. Go up most hills in top gear with the cars. But yea, awful sounding engine, especially at idle, and vibrations at idle too. I used to snooze behind the ice rinks before and during the game because I'd have to drive all night to get home. The sound and vibrations at fast idle always made me appreciate the 6V92 in my own bus.
It is a cold engine. It will not get up to operating temperature until you work it hard, like out of town on the highway. That bus came from the factory with a Webasto to bring the engine up to temp and keep it there when idling and driving around town. It is also a great pre-heater.
Also very reliable. Electronic, but never any trouble. All I ever did to it was change the oil every 250 hours, and adjusted the valves once. About 8 to 9 m/Cnd gal, 7ish US.
If your bus has a big enough engine bay, the S60 would be a great re-power.
The DD15 in today's OTR trucks is even better. But it will be a while before you see that in our kind of bus conversions...
JC
If you start with a mechanical 8V-92TA, a mechanical 4 stroke or electronic 2 stroke will get about 1mpg better. The electronic 4 stroke will get about 1 more mpg then the others. The new common rail Diesels will get another MPG better.
I had an 8V-92TA mechanical in my truck. The suggested maintenance was, 10,000mi oil change. At every 100,000mi adjust valves and run rack. At every 200,000mi roll in new crank and connecting rod bearings. At every 300,000mi, rebuild the turbo and blower. At 500,000mi, typically was time for an in frame overhaul.
The suggested maintenance on a Series 60 is, oil change at 25,000mi, adjust the valves at 50,000mi, then every 200,000mi after that. Perhaps bearings at 500,000mi. Overhaul at 1 million miles. See a difference?
The new DD engines have 50,000mi oil change, same adjust valves at 50,000mi, then every 200,000mi. No bearing changes. Overhaul at 1.3 million miles.
It is very hard and getting harder to find a decent 2 stroke mechanic. Series 60's were installed in every truck manufacturer before Freightliner bought Detroit in 2002. Series 60's are still being made for industrial and marine. I would pay extra for a bus with a Series 60-especially a pre-'98 EGR engine. Good Luck, TomC
If you want SMOOTH, get the 12V-71, vibrates just lie an electric motor or ZERO vibes.
Dave M
The drawback of the old 71 and 92 DETROIT DIESEL's in buses is that unless one wanted to make much work for themselves, you pretty much had to stick with those engines due to the fact that most builders designed the engine compartment and wheelbase around the shorter 71 and 92 engines. So repowering with a S-60 may cause many to conclude the heck with it that's more trouble than it's worth. But many used the S-50 which fit much easier than the longer S-60 but talk about vibration of the 4 banger...wow.
But buses that were designed with the S-60 as standard or optional equipment could easily fit one of my CUMMINS(ISM, ISL, ISX) engines. :)
As stated, those old 2 strokes could be ID'd just on sound alone. Although, that 12V-71 sounds alot like the 6-71. Still nice though.
My 5a has a 8v71 and Allison. The Allison was the best thing I ever did for the bus. I can not see doing anything about the engine. However, if I were buying something else, I would want the S-60 for the serviceability and extra power. I would accept the electronics that goes with it.
The point has been made that everyone is driving electronic cars, but the is a different story. Every little mechanic shop is equipped to deal with them at a reasonable price. However, unless you are going to learn to diagnose and repair your coaches systems, it will require a specialized shop to deal with it; such a shop might not be local or reasonable. Simplicity is certainly the ally of an amateur like me.
Quote from: Scott Bennett on July 23, 2015, 04:54:04 AM
Lol....maybe the extra 5 feet helps? I don't know, I just recently though experienced a 60 series in a new j4500 and Heather and I both could not believe the noise and vibration when he started that thing. Maybe it smooths out once it's running beyond idle rpm?
The J4500 must not have been too new as the Series 60 was discontinued in 2010 I believe. My series 60 does idle rough, but it seems smooth once up to speed.
Guy's; I have a '93 Prevost XL with the 8v92 and it is very quite inside the coach even in the bedroom.As a matter of fact ,one can carry on a fairly normal conversation standing at the rear of the bus with the engine compartment closed off ,but when you open the rear doors ,better have the ear plug's handy. I saw somewhere on here where the XL Prevost had some delam issues.Where does this happen? I swear there is a rivet every six inches on this thing!!
XL's don't have the delam problem, it started with XLII's they didn't have rivets from the factory although that is part of the fix for the delam problem.
My DDEC II 8V92 got 5.5 MPG. It was smooth that's about the only good I have to say about it. I've never thought it sounded good, it seemed like it was turning about twice the RPM it was. My Series 60 is getting 9 MPG towing my 1/2 ton GMC truck. I don't have to worry about the oil level, it never moves, the oil stays cleaner loner, no air box drains with oil dripping out and it starts great when it's cold outside. I could go on with the good. Not much bad. It does vibrate some at idle but most of that is my fault because I used 8V92 engine mounts, I hope to correct that this winter. For me I couldn't go to sleep with a 2 stroke under the bed.
Ken
If I were rich, I'd put in a twin turbo 12-71 into my truck-no other engine sounds like that. Course, a 16V-92TTA would be good too. Good Luck, TomC
Yep.. 20+ years ago when we were all racing ort tractors the one sound stuck in my head is Sledgehammer 's compound turbocharged 12v71at 150lbs of boost pulling 3500rpm through the gears...rdw
12V71 was an aircraft engine wasn't it????
https://en.wikipedia.org/wiki/Allison_V-1710
maybe it could be used in a gm coach
Music to my ears!
https://youtu.be/81knfhn2WZU
Quote from: IMABUSBOY on July 25, 2015, 08:00:59 PM
Music to my ears!
https://youtu.be/81knfhn2WZU
LOL, I can go home now. I've seen it all.
Hahaha! I'm literally laughing out loud. Wife thinks I've lost it hahah
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