[HoosierDaddy]

I had a '78 Newell with the 555 Cummins in it. The 555 is a smaller version of the 903. It was adequate for the 35' Newell. It sounded great, did not leak or burn much oil and got 7 mpg. It would slow down on a long hill but would run 70+ mph all day long on the flat. These engines were used in short-haul day cab trucks as well as agricultural and construction equipment in the US. There were some issues with crank-shaft breakage when placed in severe duty (military applications) but they seem to hold up very well in motorhomes. One key issue on any motorhome is cooling system maintenance. One should be very thorough on keeping the radiator clean. Mine get steam cleaned annually with Lighter cleaning between trips. If you are looking to buy a motorhome check the coolong system thoroughly. The older rear engine coaches blow the cooling air out the back through the radiator. Consequently any oil leak gets blown through as well and will quickly plug the radiator as dirt builds up on the oily surface. Also diesel engines of this vintage typically had "drip tubes" for crank-case venting. It is normal for a small amount of oil to exit those tubes. The tubes on my 555 exited the top of the valve covers and terminated near the bottom of the engine.