Tomc Luvrbus and the collective :) cummins power question

[Geoff]

Ok so I'm taking this this weekend and fixing the bus.. Ripping out the rot and going to town... I've been researching power from the cummins and I see I can pump 400hp out of this monster pretty darn cheap...but the Trans can't do it I remember the mention of a 2000 series Trans could do the job.. I'm attacking this head on folks with 9/1/12 being shakedown....the checkbooks open and I have a whole Lotta work to do.. Now the clincher: I want a mechanical Trans not electronic, does such a beast exist? Can I beef up this one?

1991 Ward Senator
Crane Carrier chassis
5.9 w/AT545

1 obsessed driver and passenger with too much time on our hands

Have fun !

Eric

I DO have fun!  But it is in my 350HP RTS bus conversion with 4:11 gears that give 80 MPH.  Personally, I think you bought the wrong bus.  A 5.9 isn't going to get the power you want, bail out now and cut your losses.  Once you commit to a bus the price of conversion doesn't get any cheaper, so start out with a good platform that will give you the power you want from the begining.

--Geoff
'82 RTS AZ

[belfert]

I have to agree with Geoff here.  You're putting a lot of time and money into repairing rusty rotted steel on a bus that doesn't even have a power train you like.  I would suggest looking for a better bus that has the power you want.  The problem with a lot of schoolies is they don't have much power as they are designed mostly for city use with stops all the time.

[Brassman]

You know, ekhedge, that this site is primarily of inter-city buses, though many started with a skoolie (& some of us are still there), so there might be a bias here. But then again, as you know, there's a lot of knowledge here.

If you got the time and money--do it, but a rust free rear-engined school bus with a dt466 or cummins 8.3, and an mt643 transmission can be had for less than $5,000, and probably around $3000.

[Eric]

Well all thanks for the input! In our time constraint we are moving forward with this for now.... Wife already Ok'd saving a few years and buying something later model we are fans of late 90's Prevost or save up for a D series MCI we just need to get something on the road ASAP ! When we aren't moving we don't make money!

Thanks Again!


Have fun !

Eric

[chev49]

Speaking of Bomag.... asphalt rollers that is... which i have worked on many. The little self contained cooling diesel engines should make a great engine for a generator... My neighbor bought several of them for a large contract he had.

Sorry.. a bit off topic

i do like my 3208t cat boat anchor engine...

[Don Fairchild]

Eric, with the small cummins engines you have to build it to a cpl# going from one hp to another will require a lot of parts like head pistons camshaft injectors and pump. my cpl book is only up to 2004 so it wont cover a lot of engines. If you know someone in a pick up truck wreaking Yard you could go over and have them look up what year a 250 or 300 hp engine came out in the dodge trucks and find that engine. I know that most of the 97's were 215 hp. If you find a navy marine engine at 450 hp understand it is not a 5.9 They have there own blocks crankshafts and heads cast to there spec's and put together by shop other than cummins. these engines are bored and stroked and run real good but you may not be able to keep it cool in a bus. They use the ocean and will still have problems when in the Arabian gulf during the summer.

Hope this helps

Don

[RoyJ]

The 5.9 / 6.7 ISB can make quite a bit of reliable power, just not at commercial duty cycle (big difference between reliable and high duty cycle)

A mechanical 5.9 with P7100 pump can make upwards of 400 hp, quite reliably. You want towing oriented compound turbos and a large intercooler, with freeflow intake (which any bus already has). This will give you a lean burn and low EGTs. Pickup guys only want a burst of power, so their version of a 400hp engine would only last a couple days in a bus.

A late 6.7 with no emissions can make 400hp without a hint of sweat. They make 360hp, factory stock, choked up with EGR and DPF. Take those off and you're pretty much at 400hp factory stock.

The thing to keep in mind with a 400hp 5.9 is that you can't always use 400hp. Restrict yourself to no more than 250hp on a continuous basis and use 400hp only for passing and hill climbs. When OEMs tune a modern coach for 400hp, they're designed to run at that power all day long, that's why it takes much more than 5.9/6.7L displacement.

Remember, 5.9s carry loaded, 36,000lbs school buses all over the country...

[RoyJ]

Just to follow up what I said with an example, here's a very good towing setup on a F350 with 6.7 Cummins swap:

http://powerstrokearmy.com/forums/showthread.php?t=17411

He's aiming for a reliable 600hp, with a GVW of roughly 25,000lbs combines. Tone that down to 400hp, and I don't doubt for one second it can't drag a 30,000lbs bus around for a long time. Now, if you have a 50,000lbs 45', that's another story...

[luvrbus]

Work any small engine outside it's boundaries they don't last Davenport and his son have some heavy duty hauling stuff he runs KW's because he is a KW dealer and can only get the MX Pac engine or Cummins so he runs the 14L Series 60 he can buy it he sets those at 700+ hp and dragging 16+ axles with 140 tons + loaded he shucks one every 125,000 to 150,000 miles.

When I was there for a visit he had bought 3 new FreightLiners just to get the DD15 engine he won't use a Freightliner only KW trucks sorry TomC moral of the story if they don't have enough @$# to start with none will last as Roy points out