RMM Rendezvous 2000
The Y2K Rocky Mountain Moggers Rendezvous was held in Southern Wyoming at the Lake Owen Campground. Above, you can see the view from Camp. Kent Drummond and Dana Stickley did a great job scoping out a fantastic campground and scenic trails. I know we'd all like to thank Dana and Kay again for their hospitality and lunch on Saturday! Also, Dana organized the decals and T-shirts and they're excellent too.
We took an all-day trail ride on Saturday, heading south along an old railroad right-of-way and Forest Roads. Here's the group, with Kent Drummond's 404 in the lead...
The final destination was south to the North Sand Hills in Colorado. Here's the view of them looking southwest from a ridge above...
Saturday's trip was fairly uneventful with just a few vapor-lock problems for some of the 404 Unimogs. On Sunday, six Unimogs made a "short" trip through the forest. A couple trees had fallen blocking the road right at a really boggy spot. Duane Russell almost made it across the smaller tree but got hung up on it as it was just too slick. The gang freed Duane and Bob Newsome followed behind in his 416 Expedition. Having a "little more" weight than Duane, his back axle found the really soft stuff. His PTO winch made easy work of the recovery however....
I didn't participate in the daily trail rides as driver. This was the maiden voyage for the 300UD - the OM617A-powered Unimog 404.1 hardcab. (It was also the first trip EVER in this Unimog that I've had since June of 1998, almost exactly two years prior. It was our first experience with every mechanical system on board and I didn't know what to expect, so I expected the worst.)
Being a test flight, and knowing that we had about a hundred miles of VERY barren dirt road on the way home, we decided to keep our camper parked and ride along with friends. Kent was most generous allowing Charlis the Mog Dog (as he's now known...) to ride in the back of his 404. Charlis thanked Kent with a nice big dump in his truck on Sunday. (SORRY Kent!! Dogs will be dogs, right? At least now he can say he has a Swiss 'dump' bed.)
Our trip home through the high plains was fantastic. The 300UD moves along effortlessly and without much pressure on the throttle pedal. For this trip, I was using the stock Unimog cooling system and it does the job nicely IF the Unimog is driven under "normal" M180 power levels. When the engine is asked to make extra power, the temperature gauge really shows it. Slowing down will bring things back to normal (180°F) so we didn't push it. I did test my old thermostat before using it and it was not opening correctly. It seemed sluggish and about 15 degrees off but there was no time to replace it before the trip.
Certainly, if a new thermostat doesn't do the job the solution will be to enlarge the radiator for more heat transfer. I do see a benefit to the way things are right now. The engine temperature only goes above 180°F when climbing hills at a rate much greater than the original engine would provide. If the stock cooling system is being taxed, so probably is the rest of the drivetrain. Although I have two rebuilt transmissions on hand, I am not interested in using them any time soon. My current transmission seems very tight and used (leaked) no measurable amount of oil on the entire trip.
For reference, we met up with friends in Laramie and ran with them (all M180 404s) to Lake Owen. Running at their speeds, I never saw the temperature needle climb above 180°F. As I said above, if you keep the original Unimog cooling system and drive so that it can handle the OM617A's heat production, hopefully you'll stay within the limits of the rest of the drivetrain.
Here's a picture of our 300UD on the road home. That's Andie in front, and our MogDog Charlis next to her...
The Unimog was running very well and all systems seemed happy at 75 kph on the dirt roads. The weight of the radio box in back and diesel engine up front really makes for a smooth ride on these surfaces. We were able to maintain 75 kph up hill and down, with ascents bringing the boost level to 10 psi and engine temperature to a livable 190°F. Sure she'd have gone faster, but this was a workable compromise. The engine conversion was everything I wanted it to be. I am very happy with it! This camper is much more drivable than our mostly stock Swiss truck which is over a ton lighter in weight.
The really great ending to this trip was the fuel mileage... We crossed 225km using exactly 10 gallons of #2 fuel oil. That's 13.95 MPG! Did I mention I was happy yet? ;-) Click here to view a 9-second MPEG of our high plains cruising!
Since that maiden voyage, I discovered some fuel leaks and also fabricated a new fuel tank. The original split tanks don't work well with the diesel engine, due to the fuel return. It's impossible to get ALL the fuel. With the fuel leaks stopped, I'm getting 14.5 MPG on the dirt roads, and 16.9 MPG on the pavement!