6.7 Cummins, Decent Engine?

[tororider]

There are several busses for sale near me that have the Cummins 6.7 ISB engine. I really want an 8.3, but I haven't been finding any, and these ones are close enough I can go look at them easily. Just wondering if they are decent.

36-40 foot bus, I'd love to tow, but not much. I may do the occasional mountain, but not on a regular basis.

Thanks for any help.

[o1marc]

They are listed as Cummins most reliable motor, but is prone to the dreaded emission equipment gremlins. It was designed as a light and medium duty pick up truck motor.

[PNW_Steve]

I LOVE my 5.9 in my 2004 truck!

No EGR, no DPF etc.

Personally, I would avoid the 6.7 because of the emmissions gear.

BTW: These engines were developed in a joint venture with Case & Cummins for agricultural applications. MD vehicles and marine came later and last to the game was the Dodge pickup application.

[wrenchtech]

If you really wanted to put some effort into building the high performance 6.7, you could do a P-pump conversion on it. You wouldn't have any emissions gremlins and you would have an easy 350 hp and 800 tq. There is at least one live fuel adjustment device on the market that will let you "roll coal" if you want or dial back for economy from the comfort of driver's seat. And because these are automotive parts the prices are already fairly low and falling. I just took a look at the car-part.com where I noticed that the price of used Allison transmissions is plummeting to the point where you can get a six-speed with less than a 100k miles for less than $1000. We are living in a golden age of diesel technology and market forces!