bvanetten said:
Ok. Good info. As much as I love my 5. 9 I too was thinking it was a bit small for a 48 to 72 passenger school bus. I wish I could find one with a 8. 3 Cummins, that would be a no brainer. Good to know that the 8. 2 detroit is something to stay away from.
I have worked on a bunch of buses, so here's my take on it...
Yeah, the 8. 2/8. 2T Detroit is a pile of junk. Its inherently a bad design, and was one of Detroit's first offerings in the 4-cycle market. Its biggest downfall is an open-top block design, and small (14mm) head bolts on the early models. Eventually they changed the design to incorporate 15mm bolts with a new torque spec. Seems to hold up better, but still problematic. Injector timing and rack adjustment are extremely critical.
The 5. 9 is way too small for a bus, thats for sure -- even in 230HP trim. Most 5. 9 bus engines are rated at 175 or 190 HP. The 8. 3 is better, but good luck finding one in a bus. Extremely rare. If I were you, I would try and find one with the DT466 or DT466E. Both are great engines, and capable of excellent power. Personally, for daily use, I like the DT466E. Its clean, quiet, and has gobs of low-end torque. The mechanical 466 is good too, but a little rough around the edges.
In a small to medium sized bus, the T444E is a superb option. It too is a proven performer, and delivers good economy and performance. Some older models have the IDI 7. 3L, which is also a good engine. A little underpowered, but handles the load well. Efficient too, and very easy and cheap to work on.
Newer buses can be found with the Cat 3126 (C7). Good engine, decent power. But repairs are expensive, as with any Cat engine.
Stay away for the 3208/3208T Cat. Its 10. 4 liters of slow, ineffecient iron.