Diesel motor selection?

Question

I want to find a suitable replacement for a 454 gas motor in a 30' RV. I was leaning towards a 4.8L Isuzu NPR turbo diesel. I want to get good mileage with this swap Looking for 25 mpg. Don't need pep. any suggestions

Answer 1

I would go with a B series cummins.  They are relatively inexpensive and you can get parts anywhere.  If you get a 12 valve model you should get 200 horse and great mileage.  There torque curve is a lot different than than the 454 however and even if you could find an adapter kit and flexplate the torque and power pulses would probably tear the TH400 apart.  If you go to the wrecker and find a pre-1998 dodge ram get the engine and transmission.  The 12 valve doesn't need a computer to run either.