Repower expertise

[luvrbus]

I delivered a 42 ft S&S job with 3 slides to Phoenix for a trade out from another dealer for a different model (floor plan) back in Feb can't say I was impressed with the 425 ISL pretty gutless to me,the one I brought back had a MaxxForce 10 to me it had a lot more power and a nice flat torque curve with less hP and I know the fuel mileage was better according to the Sliverleaf I got 5.3 on the ISL and 6.6 on the MaxxForce 10 I never been around the Navistar engine before but it impressed me sorta of lol

good luck

[TomC]

Another engine that occurred to me is the Mercedes-Benz 4000 Engine.  Up to 450hp and 1650lb/ft torque and weighs just about the same as a 6V-92TA!  Good Luck, TomC

[blue_goose]

I think your turbo is above the 8v92 if it is you have enough room to install a series 60.
As you know I like the series 50, but for your bus and the way you move around you will need all the power of the series and at least a b500 trans.  If you make the change the rear will also have to be changed.  Some where between 4.10 and 4.60.  The only engine to stay away from is the Cat c13.  No one seams to like those and the fuel milage is bad.

[Sean]

Thanks, everyone, for the responses.  Tom, thanks also for the voice message; sorry, but I was up to my elbows in grease when the phone rang.

Here are some additional thoughts and clarifications:

First off, I am definitely NOT looking to swap my current 8V92 for a different 8V92.  Now that it's out, we will do the end-plate gasket repair regardless, as any potential buyer for the engine will want it in proper working order.  My engine has 165,000 total lifetime miles on it, and only 35,000 since in-frame overhaul, so I am certainly not willing to trade it for a different 8V with more miles or an unknown history.  Trading to a different 8V also does nothing to help with the fit issue.

Next, a Detroit Series 50 or 60 will NOT fit.  Yes, our 8V92 has the turbo on top and so the engine/tranny assembly is 51" tall, but only at the very back.  My engine bay has a recess at the very back to clear the turbo; that recess sticks up into our wardrobe in the bedroom, and by removing the bottom section of the wardrobe I can open a hatch and access the turbo.  However, immediately forward of that recess the engine bay height drops by at least 8".  Any powerplant that goes in can be no taller than perhaps 43".  As Mike has observed, we can go no lower than the skid rails at the bottom, and right now the oil pans are just a hair above the rails.

While Mike is correct that the drive shaft is about 36" or so, the reality is that there are only a few inches between the front of the tranny (which, on the HTB748, is the output retarder) and the tie rod for the tag axle.  So we really can't get much longer than the existing powertrain.

Now that it's out, I measured.  We need to keep to around 90" in total length, 43" in total height, and 36" in total width.

Of all the suggestions thus far, I am thinking that the ISL/B400 combination that Tom likes is going to be the best fit.  For one, it will fit into the space with no trouble.  For another, it will shave nearly half a ton off our overall weight (which will compensate somewhat for the 50HP loss).  But most importantly, I would guess that there are complete take-outs available from wrecked coaches.  That said, I am not averse to one of the other suggestions, so long as I can find one in the next few days and it fits the space.

So here are my further questions:

1.  I have a 4.3 rear end (not subject to change; too much work).  Will the ISL/B400 work with this as-is?  I note that, for example, Monacos equipped with the ISL had 4.78 rears.

2.  Does anyone know of a powertrain that would fit my coach that is available right now?  I'm willing to fly out, make the deal, and bring it back in a U-Haul if need be.

I'd like to make a decision no later than tomorrow afternoon.  By then, Choo-Choo Express should be mostly done with the 8V92 and the work in the engine bay straightening the bent skids and rails.  When they are ready to put us back together, I want to be able to either give the go-ahead, or have a concrete date in the very near future when a different replacement powertrain will be here for installation.

Thanks again.

-Sean
http://OurOdyssey.BlogSpot.com

[luvrbus]

Sean, I did some checking for you on the ISL 450 my guy at Southern Plains in Houston said do your homework that is a 2011 emission engine and they are giving problems he said if you can find one the ISX 11.9 would be a better choice for you at 48,000 lbs but it still a emission engine unlike Tom he doesn't think much of the ISL pushing that much weight day after day he said expect between 5 and 6 mpg with the Allison and 4.33 gears at your weight.
That is going to be a tough find used with all the parts according to him


good luck

[Sean]

Thanks, Clifford.  I don't think I'd be looking at the 2011 model; the ISL 425 has been around since 2007 with the corresponding emission specs.  Also, I don't think I am required to install the aftertreatment (can someone confirm this?).

I'm not sure an ISX/B500 is going to fit.  I'll need to track down the specs.

-Sean
http://OurOdyssey.BlogSpot.com

[luvrbus]

Sean, if the ISM will work for you I can get the 500 hp brand new no rebuild 0 miles from my friend for around 18 grand he paid a lot more than that from Cummins

good luck

[TomC]

Sean-at least in California, RV's are exempt from smog laws-as to retrofitting to up grade.  Any new coach (like a S&S) will have to come up to current standards though.  Like my truck, your bus is exempt-at least in California.

With the 425hp and 1200lb/ft 2007 model and with your 4.30 rear end ratio running the B400 @ 48,000lbs, your startability will be 34%!  Freightliner requires 16% for on road and 24% for off road trucks, so you're way over.  With the .75 in fifth you should get 1564 @ 60; 1694 @ 65; 1824 @ 70; 1955 @ 75.  Then in 6th you should be at 1468 @ 65; 1581 @ 70; 1694 @ 75 (which will work just fine).  Whether or not it will pull in sixth isn't important-the transmission will decide that.  Just make sure you do have all 6 gears available.

Everyone thinks that 48,000lbs is heavy (and it is for a bus), but our trucks are running with this kind of power.  Freightliners ISL Natural Gas has only 320hp and 1000lb/ft torque and we're running them in 80,000lb trucks.  Granted they have 6.14 rears and only top out at 65mph, but the driver's love them (mainly because of the Allison 3000HS).  There are many costs involve with an engine.  And as you get bigger, the costs go up.  The 8.9 liter Cummins ISL is a heavy duty medium sized engine with wet cylinder liners.  They are just exclusively the engine now for transit buses (at 330hp and 1000lb/ft torque)-but then again you're service and driving habits are no where near the severity of active transit buses.  If you do choose a ISL make sure that it has common rail fuel injection-you do not want the old style rotary injection pump (that was very problematic).  Good Luck, TomC

[TomC]

The B series Allison transmissions are cut back as to power for longevity.  You should stick with the MH series and then if you need to get more ground clearance, you can switch to a shallow oil pan (typically 3 pan depths are offered).
ISL and 3000MH Total Length-72.69" x 27.7" width x 45.9" tall weighing 2162lb for the engine & trans.
ISM and 4000MH Total Length-81.94" x 36" with x 50.4" tall weighing 3001lbs for the engine & trans.

To bad the Mercedes 6V-2000 series isn't available in this country-would be a great engine for your bus and fit quite nicely.

The only other engines that come to mind are the International DTA530 (which I wouldn't suggest in a recent engine-mucho problemos), or the Caterpillar C9.  Both good engines, but I would still stick with the Cummins ISL.  Good Luck, TomC

[TomC]

Another engine to consider is the 2004 certified Caterpillar C9 (don't get any Caterpillar that is 2007 certified-just a bunch of problems).  Even though you have to run their special muffler with catalytic converter, they were not any problems with them.

C9 and 3000MH Total Length-77.29" x 35.2" width x 42.1" tall weighing 2035lbs for the engine and transmission.

I have at least one customer using this engine with 350hp and 1150lb/ft torque with a 10spd running 80,000lbs between Portland, Or and Seattle, Wa and very happy with it.  The C9 was also made in a 425hp and 1200lb/ft motorhome version.  I can't quite remember if it has a Jake brake capable-but you have enough length to find one with a Allison retarder.  Might be a good choice since it seems to be a bit shorter of an engine and like the ISL is a wet cylinder engine.  Good Luck, TomC

[Sean]

I've been on the net all morning (well, other than the time I spent turning the crank on the 8V while the mechanic watched the alignment marks; I have great compression so my workout for the day is in the bag).  I simply can not find physical dimensions on the Cummins engines.

Can anyone give me the dimensions of the ISL and ISM engines?  Based on what Tom posted about combined dimensions, it's looking like the ISM simply will not fit (but that's a great offer on one, Clifford).

-Sean
http://OurOdyssey.BlogSpot.com

[luvrbus]

Thought I would give you 1st shot another guy here is wanting it bad so I am going to let it go now

good luck

[Boomer]

I'll throw my two bits in here because I have a good idea about how Sean uses his coach after reading his blog for years, and also that I have a pre EGR ISM and 4560 in my coach.  I agree with Tom's recomendations and believe you would be satisfied with the ISL.  Perfect world, a pre EGR engine would be preferable but that may not be possible.  All this being said, the conversion is still a tremendous undertaking, simply putting it in the bus is the easy part.  Harnesses and wiring are major, as is the configuring of your CAC and piping.  A radiator overhaul or replacement would also be optimal.  Unlike the S60, the Cummins has both intake manifold and turbo on the same side (your radiator side), so it gets pretty crowded on that side what with exhaust, coolant, and CAC piping all living at the same place.  I assume you would be using a stacked CAC rather than a remote mount which would require another cooling fan set up.  I don't think your gearing would be any problem at all.  I have a 3:36 diff and simply run in 5th for the speed I like (62 mph, producing just under 1,300 rpm).  Our winter trip was over 8,000 miles over all kinds of terrain and it produced 8.8 mpg off the Silverleaf.  Whichever engine will require a coach oil pan, the S60 and ISM pans are upward of 2K for a new one.  I lucked out and found a used one for 400.00.

Anyway, IMHO I think you would be happy with an ISL, and more happy with the ISM if it works out.  From a dollars and sense standpoint, it of course makes more sense to get the 8V92 problems worked out, putting 30+K in old buses that are going down in value so quickly is insane.  But then again, our whole hobby is insane, LOL.

[Sean]

Clifford, thanks for keeping me in mind.

Mark, thanks for the confirmation of Tom's numbers.  I have a line on a new 3000 MH made for an ISL 425, so if I can just find an ISL 425 with the correct pan (I'd assume, since this is a motorhome engine, that most would have the low profile pan anyway) I'd be in good shape.  Of course, the price would have to be right.

Yes, I would stack the CAC on top of the existing radiators.  They're overkill for the ISL anyway, but no percentage in changing them out.  I might re-pipe to use just one of them instead of both, and see how well it does.

You are right, of course, about the investment.  This would be, for us, as much about improving mileage and driveability as it would making for an easier fit, and I'd be willing to spend a little for it.

Anybody know what I could get for the 475-horse 8V92TA (DDEC-II) and HTB748 if I sold them outright?

-Sean
http://OurOdyssey.BlogSpot.com

[luvrbus]

Sean, speaking with Bill again you mention 2005 he said don't buy a ISL manufactured between Oct 2005 and April of 2006 lot's of problems
.As for selling your engine and tranny maybe 3500.00 the 748 is not a highly sought after transmission core price is about all that will bring not trying to rain on your parade here just cold hard facts when people tell you how much money things are worth I say sold to them lol 

good luck