Engine choice question

[Ace]

contemplating an upgrade possibly in the near future, and more likely early next year, from the current 8v92 to a DD 4 stroke in my H model Prevost, I see there are many series 60's available at all different prices, but my question is, although for obvious displacement reasons, what are the advantages and disadvantages between an 11.1 and a 12.7 ?

Also is there an adapter harness that would adapt a DDEC 2 to a DDEC 3? Really don't want to change the whole harness if there are other means.

And, what about the trans? I know I could probably get away with what I have (740 non electric) but would a 6 speed be better for fuel mileage or what else would anyone recommend that is readily available that would just be better and not having to sell the farm to acquire one?

Just trying to do some research before the journey. I know a 60 series will fit my 40 footer H model because my friend Bill has the same exact bus but his 4 stroke was factory installed so at least I would have something to go by as far as what is needed!

Thanks

[kyle4501]

A series 60 will make power & want to cruise at a much lower rpm than your 2 stroke, so you'll need either overdrive gears in the transmission, or a different axle ratio.

I'd think a suitable transmission would be easier to get than re-gearing the axle. The benefit of the right electronic trans is the motor & trans will work better together.

Have fun on your quest!

[TomC]

Ace- the difference between the 11.1 and 12.7 is the crankshaft and connecting rods-same pistons.  Also I believe different injectors and turbo.  I would try to find a good 12.7 liter since you can go to an easy 500hp and 1650lb/ft torque-whereas the 11.1 is a maximum of 410hp and 1450lb/ft torque.  But either engine will run well for you.

Not sure on the wiring harness- my gut tells me they are different.

If your bus is geared now for the 8V-92TA, it will probably be geared to low (spinning to fast) for the Series 60.  Using the B500 World transmission is the best way to offset the rpm difference.  The first four gears on both the HT740 and B500 are basically the same with the B500 having both a .74 and .64 overdrive.  So for instance if your 8V-92TA is geared to top out at 75mph at 2100, now the World transmission in fifth will be 1554rpm-which is perfect for the Series 60.  If you took it up to 80, you'd probably be able to drop into 6th gear which would give you 1433rpm-again just right.

Changing to the Series 60 will make a night and day difference in both your performance, noise and fuel economy.  With proper gearing, you should be getting 1-2mpg better with the Series 60.  Good Luck, TomC

[TomC]

Finding a Series 60 with an Allison B500 already attached, maybe a bit in the hard side.  Might try to find a Cummins M11/ISM with the Allison HD4060 from a wrecked trash truck-since there were hundreds of these made-plus the ISM is a much smaller in size engine then the Series 60 making the conversion that much easier.  Good Luck, TomC

[luvrbus]

Ace,Prevost used 4 different tags on the H40 if you don't have the right one you will need one from H-40 with the 60 series or one from a H-41 you may not want to swap, for gearing Prevost used 3:21 to 3:73 for the 92 series 8v92 and the 6v92 the 60 with the world 6 speed it used a 4:56 ratio.
Buying a engine cradle and getting rid of your new radiator it is not a easy swap going from 92 series to a 60 in a Prevost with enough cash it's not a problem if you do swap don't waste your money on a 11.1 I know the 11.1 are cheap now but like all things there is a reason fwiw if the 60 series is not from a bus there is still more work for you


good luck

[H3Jim]

Hi Ace,

Or try to find a non EGR 14 liter series 60.  You could tow anything up any  hill at any speed.  I think trying to find an H3-40 with a series 60 and rob some parts - although parts buses are almost non existent, especially with a series 60.  I think the entire rear end is different between the H3-40 and the H3-41.  For the 41, they just used everything the same as a -45, but just cut out one of the bays.  They used the same axles and suspension capacity to keep their manufacturing space efficient.

So having said that, since you will have to spend $ on custom fitting, maybe just find a good deal on an engine and tranny that could be made to work and go for it.  Jim shepard has some good experience4 fitting the series 60 into an eagle.  As has been said, you will definitely need another tranny. 

I do run in 6th gear on my world, and I am at about 1550 rm at 65 or so. 

Or the least espensive way to go would be to have Don Fairchild rebuilid your 2 stroke and make it sing...

[robertglines1]

Ace,I found a 2000 sixty series with a Eaton 10 sp autoshift with change over parts reasonable is pre egr. You might ck. and see if the Eaton will clear your tag. as it is smaller than the B-600..the engine and transmission were together as a unit to computers were still talking to each other..Bob

[belfert]

I wouldn't do an 11.1L Series 60 if I was doing a repower.  Detroit stopped making them in the mid to late 90s.  The highest power rating is 400HP if memory serves.  It would be worth it to find a 12.7L instead.

[Van]

I second letting Don tweek it up Ace, You need to come out here any way. I already kicked this can around the yard a few times, 60 series or 8-92? Since I already have the holes for the 8-92 in my rails the answer is obvious, Build a stout 8-92 and maybe some day I'll get a chance to put in that Turbine