The following is a 1st draft only and we will try to share our experience with other Diesel-Experts like Kai Serrano, etc....
The trip to Moab (Utah) served as a tune and test-drive for our new
Diesel Unimogs (orange 416 Crew-Cab). I tuned the injection pump
for more inject-volume (110 hp tuned to 130 hp) and for higher RPMs (2800 tuned to 3050).
This allowed me to achieve a top speed of 60+ mph with 14.5x20 tires. A comfortable
traveling speed is 50 to 55 mph (uphill/downhill no difference). While I was watching the
pyro-gauge climb to 1250 deg F I was able to manage a very long stretch of 6% uphill (5
miles) between 35mph to 40 mph. I could have gone faster, but because of the exhaust-temp
I was not allowed to.
Warning: Do not attempt to hot-rod any Diesel-Injection pump without a previous Installation of an Exhaust Pyrometer (When Kai got asked about how to tune the pump he said he will only release the info after a Pyro-gauge got installed). You can and will fry the engine with the wrong adjustments without the appropriate exhaust-temperature monitoring capability. If you are unsure about the whole procedure, please consult your local Diesel-Mechanic for a 2nd opinion.
Details: Before you make any changes, please mark the
original positions, just in case if you want to reverse your experiment. Please install
the Pyro-gauge at the very beginning and run a base line (original setup readings) before
you proceed. The RPM increase can be done by adjusting the acceleration lever limit screw
to allow more travel (about 2 to 5 turns, please try it in steps). It will require a
re-adjustment of the accel linkage as well. In most cases you will have to remove the
protective plastic cover over the adjustment screw. Do NOT turn it up too high because
this is the only mechanism which prevents the engine form a run-away. To turn off the
ignition doesn't work with a diesel. If your throttle linkage gets stuck at full load you
have to push the clutch, come to a stop and then choke the engine by releasing the clutch
in high gear. If your RPM limiter is to high you will damage the engine doing so. The
engine is never supposed to reach higher NO-LOAD-RPMs than 3250 (full throttle and clutch
pressed or neutral).
Caution: Once you tune up your injection pump it's essential that you use the installed Exhaust-Temperature-Gauge (Pyrometer) to monitor the exhaust temp. It's very critical that you watch the gauge religiously going uphill for a longer stretch. Kai and myself do not recommend to exceed 1250 deg F for any longer periods (maybe 10 to 15 seconds or so). Your pyrometer will become at least as important than your speedometer. After a few days you will get more acquainted with it and it should become 2nd nature to keep an eye on you pyro-gauge (for the hotter pump-delivery settings).
Summary: The following table are some of our notes on the way home. We have no data available on the trip to Moab and we did some of the final adjustments in Moab itself. We did a little off-road at a friends place in Minden (Nevada) and therefore the slight increase in mpg's. Our trip was done on Hwy 50 west and we covered more that 10 summits with an average elevation of 7000+ feet. We kept the pyro at 1100 to 1250 deg F most of the time and the average speed was 50 to 55 mph except uphill. We were able to sustain 35 to 40 mph during most 6% uphill grades (pyro steady at 1250 deg F and NOT full throttle). The engine-oil consumption was 3+1/2 quarts of oil, with some being lost through 2 small leaks which I'm trying to fix in the next few days.
Disclaimer: The tune-up/hot-rod procedures can and will put more strain and wear on your engine and drive-train components. If not observed and handled properly it can roast your engine or parts of it. It serves only as a guideline of what your 406/416 Unimog would be capable of. Unimog-Forever does NOT recommend it and can not be held responsible if anything goes wrong. Sorry about this, but it seems the appropriate way in the US to protect your A.. from the unforeseen.
We are sure that You still have some questions or comments, so
please contact us at