Unimogadventures - Our build and travel thread

[Iain_U1250]

I got myself and anemometer, just a cheap one off Amazon to do a few tests on airflow through the radiator.

I've got a 16" Bosch fan I had spare off an Audi S4, and it works quite well.




I did a few tests yesterday, and some more scientific ones this morning.






I copied a similar method as another Unimog owner did on a stock mechanical fan and bare radiator.



The results are similar to what I got, and I have an a/c condenser and another fan in front of the radiator.

The airflow varies quite a bit across the radiator as you can see in the results.


I did the all the test with the bonnet up.



I'll figure out the way to fix the anemometer to the radiator and connect it to my laptop, and go for a drive and see how much airflow comes through when I am driving. I might have to resort to using cable ties and strapping it to the grill.

 

[Iain_U1250]

Another project done, I've fitted a new bigger water - air intercooler and heat exchanger, with a bigger fan as well. I found the old one was leaking after 70,000km /9 years, so decided it was worth fitting something a bit bigger, The old one developed a leak, and whilst the engine was running, the boosted air from the turbo would blow water out the system, but parked up, the water would leak out, but since the intercooler is lower than the intake, it ran back down into the turbo, not the engine.


This is the new setup








The new heat exchanger, with a 11" SPAL




This is the new intercooler - it is twice the size of the old one.

It seems like I have some thing quite similar in size to the S600 / S65 OEM heat exchangers so on mine, with about one third of the power, so maybe it is a bit of overkill.

Intercooler size. The new one has 297 cu inch / 4866cc
Heat exchanger size - 12"x12"x2" / 305x305x50mm = 4651cc

Mercedes S600 Heat Exchanger 02-05 (536-hp, 5.5-liter twin-turbo V12 )
580x 265 = 1537 cm2 x 21mm = 3228 cc


Mercedes S65 Heat Exchanger 04-05 *630hp, 6.0-liter twin-turbo V12 )
580x 465 = 2697 cm2 x 21mm = 5664 cc





The intercooler is not vertical, but tilted to that there is more space under the intercooler for the air coming through the radiator to escape out the bottom of the engine bay.



I've made sure there is enough flex between the intercooler and the engine, with a double hump hose from the turbo to the intercooler, and a 3.25" to 3" 45 deg silicone elbow from inlet to the crossover pipe, then a 3" 90 degree elbow to the intercooler.

Initial test drives have shown it is has dropped the intake air temp from around 70-75C, to around 63-70C, with out running the electric fan. I'll set that to come on with the intake temp gets over 50C, and off again when it is 45C, and see if that makes a difference.

It has all taken a bit longer, I I bought a new toy to play with - our new beach van.

I started life as an airport taxi shuttle,



but is a bit different now.

 

[Iain_U1250]

At last, finally found a header tank that will work. Just need to sort out the pipe work.

 

[Iain_U1250]

Pipework is all sorted , and it si more or less self bleeding, with the t-piece at the highest point on the hoses going to the intercooler. With this header tank, I have over 5 litres of water/coolant in the system. The last expansion tank I 3D printed didn't work, as it created air locks in the system. There should be no airlocks now, as long as the header tank is full. The tank is at the highest point I could make it under the bonnet as well.

 

[Iain_U1250]

We are getting ready to go on another trip across Australia. We have been making a few short videos on our YouTube of how we are getting ready for a 5 month trip.

I've replaced the old oil filter housing with the new design, the old ones are prone to cracking leading to loss of oil pressure.


The new one is reinforced


I also fitted a combined oil pressure sensor / warning light, so that an LED on the dash lights up when oil pressure is low, rather than me having to notice the gauge.

Unimog preparation

www.youtube.com

I also made some protectors for the valve stems on the wheels - they are quite exposed and being brass, could snap off quite easily. This should help prevent that.

We made some tyre valve protectors #unimog #unimogadventures #beadlocks #3dprinting

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I've also refreshed my tyre repair kit, with some larger patches, replaced the out of date vulcanising cement,, and added an external sidewall repair kit. We only carry one spare tyre, so need something to get us out of the bush if we get a flat. The treads on the Michelin XZLs are so thick, I doubt anything will get through it, but the side walls above the ribbed section are pretty thin.

Only one spare

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We will be carrying an extra 90lts in Jerry cans for one or two of the more remote section on the trip. Ours were looking a be tatty, so I decided to fix them up a bit.




Over here, diesel is supposed to be a yellow can, so I added a the "DIESEL" to them after printing a stencil on my 3D printer.

Last was changing the gears an seal on one of the portal axles. I had a slight leak, and I could have just replaced the seal, but I found a bit of shiny metal when I pulled the seal out - better safe than sorry I thought, turns out the gears were worn a bit. After checking the oil closely on the others, I'm happy enough that they are still good for this 15,000km trip.




It only normally takes me around 4 hours to swap out a portal, but I ran into a problem with one of the bolts on the brake caliper, and ended up having to cut the head off with a Dremel. It had locked up solid in the portal housing. I had to take the portal off with the brake caliper still attached, and then was able to push the bolt out enough with quite a few solid hits with a hammer, to get enough to space to cut the head off. Then I was able to get it under the hydraulic press and push the bolt through. Not sure exactly what happened, but seems the bolt had distorted.



I still have a couple more weeks to finish off the contract I am on, then we will hit the road and go from Byron Bay ( Most easterly point in Australia) to Steep Point ( Most westerly point) right across the middle.

We are going on an adventure

www.youtube.com

 

[Iain_U1250]

We have posted another video on our YouTube channel, this is a bit of an experiment, as this one is just the real-time footage of us driving up the Canning Stock route, not commentary or exciting bit, just what it is actually like driving across the desert. It is only 3 1/2 hour out of the 10 days we spent on the track, but it does give you a idea of what it is actually like.

 

[Iain_U1250]

If anyone was wondering how to get things up onto a 3m high roof rack...

23 September 2024

www.youtube.com

 

[Blowby]

Excellent video, we are also in a situation where a crane like that would help and I was
not able to see the brand name that you are using.Any insight to what you are using and is it worth considering?Have been trying to find something similar but to no avail.
Thanks Roger

 

[Iain_U1250]

Hi Roger, it is a Spitzlift crane, I think ours is a 900. Make sure your get enough of the strap to reach the ground, I had to specify that when I ordered it, the standard one was too short.

https://spitzlift.com/wp-content/uploads/2017/08/2017-spitzLift-catalog.pdf

It can handle our heavy wheel/tyres easily.

 

[Blowby]

Thanks very much Ian, that is exactly what I am looking for!

 

[Iain_U1250]

We are finally off on our trip across Australia, and just published the first YouTube video, it is very hot out here this time, mid to high 40C, engine is doing fine, but taking it a bit easier on the portal axles and tyres this time, we have another 15,000km to go. The tyres got up to 68C on the tar road the other day.


Here are some photos from the first week.

 

[charlieaarons]

Hello Iain. If you’re running XZLs, I think I mentioned a few years ago that a Michelin (military) tire engineer I met at a exhibition told me that Michelin military tires need to be kept <75C.
I keep track with the CTIS pressure display.

 

[Iain_U1250]

Hello Iain. If you’re running XZLs, I think I mentioned a few years ago that a Michelin (military) tire engineer I met at a exhibition told me that Michelin military tires need to be kept <75C.
I keep track with the CTIS pressure display.

Yes, thanks Charlie, will be hard to do when the tar gets over 75C, but I have an alarm set for 75C, so far, it has not gone off.

 

[Iain_U1250]

I'll will be putting these into our video of our Simpson Desert crossing, but here are some FB links to show how much the chassis flexes on our truck.

https://fb.watch/vRDBvDHyM9/

https://fb.watch/vRDKrQIBPf/

This one shows the suspension working, and what happens when you hit some really soft sand going up a dune

https://fb.watch/vREi-TQF07/

 

[Iain_U1250]

We have made it across Australia, another 10,000km mainly on dirt road and a desert crossing as well.

This is the latest fuel consumption. Things have averaged out and are sitting around 21 L/100km or 11.2mpg (US) which I think for an 8 ton truck is pretty good.




We also got stuck for the first time ever, some super soft sand on a track, and I took the wrong angle, closest we have ever come to disaster. I was too close to the side of the dune, and the wind-blown sand was so soft, that the back end just slid out down the slope in seconds. I stopped immediately, I dropped the pressure in the tyres down to 15 PSI, starting with the ones on the uphill side. As I was lowering the back rear one, I could see the truck leaning over more and the sand was moving, and was prepared to run away. I dropped it down to 25 PSI only. I then tried to drive out straight, but did not make any progress, so I reversed back down, turning hard to go down the slope at right angles.



Once the truck was stable, I was then able to drive out straight up and over the slope and we carried on, a bit more cautious on the sand blows now. Considering this was at Steep Point, the most westerly point in Australia, and nearest town was 450km away, it could have gone really badly.