We had a great time at Arkaroola, great camping down next to the river and very quiet. With the weather starting to get hot we headed up to the most isolated part of our trip. The Birdsville Track through the desert gets a fair amount of traffic in the winter months, it is around 500km of dirt road with basically a pub/roadhouse in the middle, and pretty much nothing in-between. Since it was summer, there was not much traffic - we saw one other vehicle the whole trip. It was one of the hottest days I have ever experienced. We stopped at the Mungeranie Pub around midday, and it the owner of the pub showed us that the floor under the verandah was 44 Deg C in the shade. Outside in the sun, the ground was 55 Deg C.
We met a guy cycling around Australia, he had been riding since before sunrise, and made it to Maree at the start of the Birdsville track, he made it before it got too hot. I don't think it is something I could do, I prefer a bit of luxury. He was going to Coober Pedy along the Oodnadatta track, but was staying in Maree until it cooled down
Our external temperature gauge on the truck which is in the shade, was measuring 55 Deg C air temp whilst we drove up the track. We had a very strong headwind all the way - EGT would sit around 650 Deg C on even the slightest uphill if I tried to keep at 90kph on the smooth parts, so I slowed down to 80kph and backed off up the hills and changed down if the EGT alarm went off- set at 680 DegC as it makes a racket. Fuel consumption was pretty high - around 30lt/100km, worst we have every gotten but not that bad considering the lower tyre pressure, strong headwind us being around 7.5 tons being full of fuel, water and food.
Despite the incredible hot temps, the engine stayed around 100-105 Deg C. I put in the 72 Deg C thermostat before we left, and down in Melbourne engine temps seldom got above 75 Deg C when it was less than 25c outside. Our a/c struggled to keep pace until my wife put on of our sunshade on the side window where the sun was coming in, our laser gun measured the glass at 48 Deg C and I remembered to switch off the OEM fan sucking in the outside air. When we stopped for a break around 2:00pm, I did a quick check around the truck with the laser gun. Thermostat housing confirmed as 100 Deg C, the transmission was around 99-105 Deg C, front portals, 60C, front diff housing - 65C, rear portals, 80C, rear diff housing, 70C, and Claas overdrive was 105 C. The diesel tank on the sunny side was 60C. I let it idle to keep the a/c going for the wife, and the electric fan was able to drop the coolant temp below 88C - enough for it to cycle out - then the a/c fan came on and that stayed on all the time, but it was enough to keep the engine around 88-90C. There were so many flies that within a minute or so, I had to retreat back inside the truck to get my fly net on my hat. Never seen it so bad before and we have been to some pretty bad places. We drove until the sun went down, then turned off the track and up over a sand dune to camp for the night.
It was a pretty uncomfortable night, it was still 39 Deg C at 11:30pm, and the moon was so bright, we were out taking photos at 10:00pm and even the flies did not go to sleep it was so bright. It was still 34 C when the sun came up. I'll post some photos when we get a better internet connection, we are now on our way home, it was a real test for the truck, and it passed with flying colours, seems MB know how to design a proper cooling system after all and my electric fan set-up is adequate for the truck.
We arrived at Birdsville around 8:30am the next morning, to find basically everything was closed until Easter weekend. I decided to get a move on to escape the heat once we were back on the tar roads. We did the 1600km in two days averaging 89kph. Not bad for a 32 year old off-road truck. Tyres seem to have taken a bit of extra wear at that speed especially with the tar being over 60 Deg C surface temp.
Back home now and going to do all the improvements we think will make it better. First off is the rear winch plate and gas bottle storage. Going to weld it to the back plate which has been heavily reinforced for the train hitch. I'll add the two tow point underneath, and some reinforcing on the sides.
This mog used to tow some railway carriages around, it had a plate on the dash saying "Engage Low Range when pulling more than five carriages" so the rear plate is pretty substantial compared to other mogs, so I might as well make use of it.
I will add some lighter brackets and a protection bar to hold our gas bottles, better to have them outside than in one of the storage pods. Trish will make a canvas cover for the winch to keep the dust out, and maybe one for the gas bottles as well.
