Frank's Cummins Ramcharger Page
just getting started with this page folks...
I spent some of last summer assisting with a Cummins swap into my best buddy's RamCharger. My job was the engine to transmission adapters.
It is a bit weird to drive. No range to the rpm, just lots of torque. Change gears to change speed. 35" tires and 3.27 gears and it will start from a stop in 3rd! Big grunt, turbo spools up, tires spin as you slip the clutch and you are at speed.
I am getting to like the Cummins Ramcharger a bit more, as the motor gets broken in it is getting a bit more free revving. This thing sounds like 18 wheeler complete with turbo whine.
Well the Cummins Ramcharger is awesome but just in a weird sort of way. We have been out clearing some of the inevitable bugs that pop up in any conversion like this. One of them is limited suspension travel due to the 18 quart "bus" oil pan that is currently on the motor.
I don't know if you have driven a Cummins but the motor has a great gobs of torque, limited (and low) RPM range, and very poor accelleration. The Ramcharger will lug up hills in 4th gear at 50 mph that have my 165 hp diesel (auto, 3.50 gear) van down to 25 mph and losing it in 2nd. However my van will handily out accellerate the Cummins on the flat.
Frank is "late 40'ish" and has much different proclivities than myself. We did no top speed or offroad "testing" other than plenty of our backwoods roads that have gone from packed snow to glare ice to 4" of gravy like mud in the past several days. The full-time transfercase is in response to the short wheelbase, great nose heavy bias and generally poor roads Frank has to drive on. It is working out very well in these conditions. He has a NP208 box and drveshafts from another Ramcharger should he change his mind mid-summer.
I feel the Cummins would be very good off road with its almost unstallable nature and slow accelleration. The one downfall would be the extremely heavy front axle weight. As you know, the short wheelbase Ramcharger and big tire characteristics should make this thing a real stormer off- road but we may never find out, Frank only requires this type of vehicle as a rugged "station wagon" for backcountry roads and trails. I'll work on him... <BIG GRIN>
-1982 Dodge Ramcharger, (ex-318 motor)
-Standard Dodge 4sp manual, NP203 Full-time transfercase,
-5 bolt axles, 3.27(?) gears, Limited slip installed in the rear
-late 80s "CAD" center disconnect front axle (incase part-time used)
-Cummins 5.9 litre turbo-diesel, 190 hp, 475 ft/lbs torque at 1500 rpm
-Air to air intercooler, larger rad and manifold preheater installed. (intercooler recently disconnected)
-35" x 12.5" tires installed mainly to gain gear ratio.
-The rear suspension appears unaltered (Frank didn't touch it)
-The front suspension has air bags to support the extra 400 lbs of the Cummins motor and the bumpstops are lowered until we locate and install a "pickup truck" model oil pan and pickup tube.
As an additional note the intercooler (a Volvo unit) has been disconnected because it was restrictive and a water injection device and a finned stainless steel transfer tube from the turbo to the intake manifold has been installed. The water is injected before the turbo and uses the turbo pressure to push it and regulate it. It works exceptionally well at keeping the intake air temperature down, the finned transfer tube is redundant.
A big problem presently is maintaining engine temperature. Even with spring weather upon us it is hard to keep operating temp above 120f. The first tank of fuel through the Ramcharger figures out to "about" 27mpg. This figure is very roughly calculated because a gear change and the 35" tires have made the speedometer and odometer read very low for actual speed/distance. Still, we must be with in at least 20% and this fuel mileage figure is all the more remarkable considering that none of these miles are highway miles, mostly secondary roads and plenty of rutty, snowy, muddy dirt roads. More as we go...