Diesel Engine Conversion to Frying Oil

[Oonrahnjay]

275/70R-22.5=547rpm. 4.59 x 547 x .65 = 1631rpm @ 60mph. This is good for the ISC. If you need to climb a hill, drop to 5th that would turn 1883rpm @ 60. Good Luck, TomC 

     Yeah, and if traffic is running 50 mph, that's another good place for 5th.  While I'm shooting for 60 Mph for cruise (and I think that aerodynamics -- although I hesitate to use that word in regard to my bus -- dictate that that's about the right target speed), if I needed a few more Mph in a traffic situation, I wouldn't hesitate to add a few more revs (1850 Rpm = about 66 Mph).  Cummins lists governed max speeds on ISC engines as 2200-2500, most variants being 2400-2500.  I think that the 4.6 ratio is about what I need.

[TomC]

Interesting to note that Cummins marine rates the ISC 8.3 as high as 600hp @ 3,000rpm. Good Luck, TomC

[Oonrahnjay]

Interesting to note that Cummins marine rates the ISC 8.3 as high as 600hp @ 3,000rpm. Good Luck, TomC 

     I don't know what Cummins calls that tune, but I'm guessing a really good name for it would be the "hand grenade" tune!  But I like knowing that some extra Rpm's are available if needed.