Up grading to bigger detroit

[jjrbus]

My fantasy bus has a 6V92 in it. After reading this board for many years, if money and headaches are no object go for it. It has been done!
Personally and only my opinion, with the prices of buses today I would buy a bus with a 60 series in it. All the engineering has been done and all the nasty little gremlins have been worked out.
As the Prevoosts whizz by, you will be sitting on the side of the road trying to figure out why the transmission will not talk to the engine! Or you will be thinking, they promised me this would not overheat. Actually you will not be sitting on the side of the road, you will be in a Detroit shop somewhere at $150 hour. But what the hay, money is no object and as fast as that bus is you will be able to catch up with the band.

[TomC]

Find a trash truck with a Cummins ISM and Allison 4000 series 6 spd transmission-lot of them in junk yards.  Have the Cummins built up to a 525hp and install that. Series 60, Cummins NTC400, Caterpillar 3406 are huge engines.  The smaller size of the ISM will make retrofitting much easier.  Good Luck, TomC

[rv_safetyman]

As my signature shows, I have an Eagle with a Series 60 and AutoShift.  That is a great combination.

As others have said, this kind of conversion is not for the faint of heart.  A professional conversion will cost $30-40K or more.

I have documented my conversion in some detail on my project pages (link in signature)

I would go with the four stroke as they will not cause heating issues if the cooling system is in good condition.  The 8V92 will generally cause heating problems.

We belong to the Eagles International Chapter of FMCA and a fair amount of these buses have had an engine conversion.  Most are Series 60 and M11/ISM.  The M11/ISM folks are quite happy with their option.  They did not have to raise the bed (which you must do with the bigger Series 60 and other larger four strokes).

Any of the four stroke conversions really need a gear ratio change to take advantage of the power/economy lower operating engine speed.  This is best done with an overdrive transmission.  There is a 3.36 rear end option, but that does not really get the engine in the best operating speed range for the speeds you want to drive.

Just some thoughts

Jim

[Jerry32]

Don't forget to put in that 6 speed allison with the double overdrive. Jerry

[Gary '79 5C]

My stack of cash is not so high, So I will agree with Jjrbus, as It is the 6V92T for me. I will watch as others pass me as I do 70, all the while guarding (watching) the temperature guage....
I need to install the vents in the rear engine compartment doors as well.

Good Luck,
Gary

[musicman]

Thanks alot..Ive gotten alot of good feed back and alot to think about..My bus is a 85 Eagle and shes in Excellent condition..Not a speck of rust anywhere if you can believe that..She was in Arizona to Tx all her life til I bought her and brought her to florida..I dont want to get rid of her because the ride in my personal opinion is superior to other make and models..On the other hand 30-50K is alot of money to dish out for a refit..I just need to decide which way to go...Again thanks alot folk

Chris

[DrivingMissLazy]

I upgraded from a 6V92 to an 8V92 in my 80 Eagle and I was very happy with it.
With the Allison 740 automatic I could keep the speedometer pegged and I towed a 5,000 pound toad and the coach was over 40,000 pounds. I put about 150,000 miles on it and never regretted the upgrade. Probably easier than most other replacements and that was before the electronic engines. I always got over 6mpg regardless of where I was or how hard I pushed it on my many cross country trips.
Richard

[jjrbus]

Gary, is that 5C is a Saudi model? If so it came with  oversized radiators. If they are in good condition you should not have any problems!

[tekebird]

why spend the money if you can do 75mph?  Seems like if you have that kind of scratch to drop....just go order yourrself one of the new Eagles.

[bus05eagle]

musicman the 8v92 upgrade is by far the most simple on the model 10 the frame rails are already drilled for the 8v92 you don't have to buy new motor mounts the front and rear are the same on both engines it just move to the rear about 9ins you could change to a 3.36 and get you 10 more mph and a little more fuel mileage i just can not see spending 40,000 on a upgrade that you will never recoup in years the 2 strokes have been around for 60 years and are in everthing but a airplane a 3.36 gear change costs about 2500.00 and a new radiator and fan are about 2500.00 that was about 3 years ago

[Gary '79 5C]

Jjrbus,
Good pickup, This is a Saudi with oversized radiators, which the PO overheated running to Denver in the summer. The total engine rebuild included rodding out the radiators. I have been good for 2 years and 22K miles. I have side air scoops for the radiator intakes. I saw Fred Hobe's rear louvers installation for the rear engine doors and always thought they would assist greatly. If I get really motivated I should install a second temp sensor in the other head.

Take care
Gary

[musicman]

Well it looks like a 8v92 or cummins ISM is what Im going to be shopping for now..And to answer Tekebirds question..The reason I wont go buy a new eagle is this one has alot of fond memories of my mother who passed away in Jan 06 of bone cancer..She traveled with me in the coach for about 2 years til she got so sick she needed to be near a Dr all the time..So its more of personal reason than it is money...Im far from rich but I spend 300+ days on the road and want to be comfortable and this coach is home away from home

[muddog16]

I haven't installed my new 8V92TA from Jasper Engines yet but later this summer it will go in! But I can tell you after purchasing a 8V92 for a core engine so far this engine change will be around 25K, you can purchase a core some where around 1,500 to 3,500 dollars.  A good place to start might be Sam Caylor for information and parts:  Caylor Supply - Used MCI Bus Parts
                4712 Rock Creek Rd., Rantoul, KS 66079
                785-878-3405 Fax 785-878-3427
I know it says MCI but the engines are basically all the same and he's "honest".  My orginal engine was a DD 8V71N.  Unless your a skilled mechanic, I would't attempt building one, but again its your bus do it your way! I'm sure there are many suggestions on this and you came to the right place, Guys like Tom C, seem to know their stuff too!............Good luck!

Pat

http://prevostlemirage.blogspot.com/

[JackConrad]

If I get really motivated I should install a second temp sensor in the other head.

Gary, we did this and know several others who have added a second temp gauge. If you do this you may find that your right cylinder head runs about 5 degrees hotter than the right.  I have no idea why, but almost everyone I know who has dual temp gauges have noticed this also.  Jack

[Green-Hornet]

You might just want to leave earlier!