Well, Sir Duncan, there's even more negative consequences that can be attributed to the constant use of the "oversupply" on the Tatra engines. The increased carbon deposits on the injector tips can cause the engine to produce visibly dirtier exhaust at normal operation and also a decrease in power. I remember from back in the 1970s, my dad's colleagues driving the same Tatra T813's manage to burn up and destroy injectors and melted pistons when extensively using the "oversupply" on their trucks. It's a "catch 22" kinda thing. The more that you use it, the more crappy performance you get out of that engine, which in the end causes you to use the "oversupply" option even more. The only remedy for that is to replace all injectors with new ones, check the compression and replace any cylinders, cylinder heads and pistons if needed. Make sure that, the injection pump it's metered and properly adjusted, timing it's properly adjusted and don't over do the "oversupply" again. If you do take in consideration these things I'm saying, you'll find out that the Tatra will not blow any more smoke then any M.A.N. F8, Scania or Volvo from the era of the 1970s. The thing is that these tatra's can take a beating and still run even with a few pistons running. I'll give you that much, that the products build in Western Europe were of a better quality compared to the Eastern Europe ones. That said, I couldn't consider a Magirus Deutz air cooled engine build in Germany in the '60's and '70's much better then the Tatra engines of the same era. There's that little thing about compering "apples to oranges" to be taken in consideration when talking about air cooled vs. liquid cooled engines.
I hope that you'll not be offended by the things I've said, and I look forward to have a pleasant conversation with you about the Tatra trucks.
And oh, I almost forgot. The diesel today contains almost no sulfur. The diesel of the old days had allot more sulfur which burned better in the old engines and also "old days diesel" had allot more lubricity then the diesel fuel today. It is imperative to use lubricity additives in today's diesel fuel when used in the old trucks. The old injectors and injection pumps were not designed to be used with the "dry" diesel fuel of the present day.
And live that mushroom shaped plastic button located under the dashboard to the right of the steering column alone from now one!
You also, probably know by now, that the pedal that looks just like a second accelerator pedal located just above the accelerator pedal, it's a pedal that activates a 'co centric' shaft to the shaft that turns the injection pump. The idea was: if in case the injection pump regulator goes bad and the engine goes into an uncontrollable high RPM mode without the possibility to shut it off, then by stepping on that pedal, the little shaft that the pedal activates will push the injection pump connector which allows the timing setting to a disengaged position, which will disable the injection pump, thus shutting off the engine.
A few more important things to always remember about the T813's 8X8. When going to cross a shallow river or lake trough the water, remember to pressurize the entire "back bone tube" drive train. It could cause very expensive repairs if not. Also when you start up the truck, with the engine at idle, listen for any "knock-knock" noise between the cab and cargo box. If you hear any of that, then check the U joints on the drive shaft that runs from the clutch housing to the transmission input shaft. If that thing brakes loose, well the mess it's incredible. The U joint at the front of the trany is the one that usually goes first. If that ever happens, it destroys the gear selector component and its solenoid valve that controls the airflow to the shifter servo. It also bends and brakes other stuff in it's way. A complete new drive shaft including the input to the trany, a gear selector assembly, solenoid valve, air lines and fittings will be required for a proper fix. It can ad up to allot of $$$ and allot of time. To replace an U joint it woul take me aprox half hour if I don't have anything in the front of the cargo box obstructing the floor hatch right above the transmission.
The parking brake on the T813's is very crappy. If it takes too many pulls on the lever to engage the parking brake, there's some adjustments that can be done regularly to ensure proper functioning. All though with proper parking brake functioning, I would sill put the transmission in the first gear (engine shut off
) when parking the truck. The compression does a better job ensuring that the truck will be in the same place in the morning as where you left it the previous night. It's just an Eastern European way to compensate....
.
I hope that this info will be helpful to the Tatra T813's owners on this site.
Happy trails!
Florin.