Unimogadventures - Our build and travel thread

[Iain_U1250]

No electronics at all - everything is mechanical, only wire it needs to run is to the starter motor. I have to use the hand lever of exhaust brake to shut it down, although I will probably make us something the activates the exhaust brake for a few seconds when I turn of the ignition switch to make it shut down like a normal vehicle.

 

[Flys Lo]

Not being familiar with the Unimogs, is there not a wire that runs to a fuel cut-off solenoid at the injection pump?

I'd be worried about just using an exhaust brake to shut it down in case of a manifold leak.

 

[Iain_U1250]

There are no wires at all on the fuel pump. The exhaust brake actuates the same lever as the manual shut-off lever on the injection pump. It doesn't rely on the back pressure of the motor.

 

[Flys Lo]

Ah, got it, so it shuts off fuel too. Good to know. I know you can make decent power from OM352/OM366's with winding up the fuel pump. Looking forward to seeing your final results!

 

[mhiscox]

There are no wires at all on the fuel pump. The exhaust brake actuates the same lever as the manual shut-off lever on the injection pump. It doesn't rely on the back pressure of the motor.

OM352-powered Unimogs may lack modern technologies, but the tradeoff is that they are stone simple to understand and to diagnosis and fix if there is a problem. As Iain points out, mechanical injection, mechanical fuel pump, no electrical circuitry at all on the engine. In CamperMog, which was older and even less-complex that Iain's U1250, the engine was turned off by rotating the hand throttle fully counterclockwise to clamp down on the fuel line.

Perhaps the most amazing thing was the truck electrical system as a whole when compared to a modern vehicle. My newer vehicles have electrical manuals that are fully bound books full of dozens of wiring diagrams, whereas CamperMog had one printed sheet. There were 8 fuses in the fuse block, needed for the truck's lighting system and wipers. I always believed that the old Mogs are one of the few overlanding vehicles that really could be repaired by the village mechanic in some remote corner of the world.

 

[rocrunr]

Ian when was this project scheduled for completion? lol Just when I thought you where getting close now axles and engine swaps. I guess I will have to follow along till the end. Keep up the good work my friend!

 

[Iain_U1250]

I have always said I will have it finished by December, just nver been sure of the year. My new years resolution is to finish the truck. The engine swap was not necessary, but going from 125hp motor, with the potential of getting up to 160hp, to a 170hp motor with the potential of getting 200hp seemed to be a good idea at the time. :smiley_drive:

The fast axles make a lot more sense, and since U1250 fast axles are very rare, and I could not pass on the opportunity.

I have worked out the following:

A normal U1250 ( 6.5:1 ratio) with 12.5R20 tyres can travel at 75kph @2600rpm.

With 14.5R50 tyres and a Claas O/D, I could have gotten that up to 95kph @ 2600rpm or 100kph @2700rpm if I bumped up the governor a bit.

My U1250 with the fast portal gears (5.6:1 ratio), 14.5R20 tyres and Claas O/D would have been able to travel at 100kph @2400rpm or 110kph @2600rpm which was a worthwhile improvement.

However, with these fast axles (5.3:1 ratio) , 14.5R20 tyres and Claas O/D, I can now travel at 100kph @ 2200rpm or 117kph @2600rpm. Dropping 500rpm from a the cruising speed will make big difference to fuel consumption and more importantly the noise. However, in order to be able to hold the speed up a hill or at least not to have to drop down to a crawl, I will need the extra power from the new engine.

All makes perfect sense to me, but I had a hard time explaining it to the wife

 

[mhiscox]

All makes perfect sense to me, but I had a hard time explaining it to the wife.

Yeah, I know what you mean. Be sure to let us know if you have advice to share on that. :sombrero:

Anyway, sincere thanks for another year of really great information, and best wishes for happy camper building in 2015 from those of us still in 2014 for several more hours.

 

[Iain_U1250]

Yeah, I know what you mean. Be sure to let us know if you have advice to share on that. :sombrero:

Anyway, sincere thanks for another year of really great information, and best wishes for happy camper building in 2015 from those of us still in 2014 for several more hours.

Rule no.1: It is always better to ask forgiveness than permission

New Year's wishes to you and everyone else on Expo

 

[pairospam]

Happy new year, Iain.

May this be another year full of commitment and hard but funny work on our trucks, not caring at all if we are or not going to finish them.

Greetings to Trish too.


Pairoa

 

[Iain_U1250]

Thank Pairo, I know we will both finish our trucks, as we are both mad enough to have started and have the support of our wives and family to finish it. I wish you and Carmen wonderful and productive New Year and to all your family as well.

 

[piratexpress1369a]

happy new year to you both

 

[GR8ADV]

The first photo show what it looked like when I got it home from the auction, the second what it will look like in a few months time and the third what it looks like now.

I had to chuckle at the first post from 5 years ago.

 

[Iain_U1250]

Yes, don't remind me - I promise I will have it finished by December

When I started, I had a month or so before I was going to work on it full time, then my contract got extended, again and again, then I got another contract, then another, now I have sworn blind I won't look for another contract until it is finished, only problem is people have already started asking for me. As soon as I finish one contract they are offering me the next one.


It is a good lesson for anyone starting a build thinking they can do it part time - it takes a long time, and if you are not working full time on it, then progress will be very slow.

 

[nick disjunkt]

It is a good lesson for anyone starting a build thinking they can do it part time - it takes a long time, and if you are not working full time on it, then progress will be very slow.

I learnt that the hard way too. I ended up quitting my job and still spent nearly 7 months full time, that was with a truck that needed no mechanical work and already had a nice box on the back.