Best year and options for a conversion.

[MAshley]

I have a 87 U1250 Unimog and I have been thinking about a conversion to a CTD. I have a few Q's that I hope can be answered here.



Google Unimog and you will have more info then you know what to do with. But basically the motor is a OM352A 125HP Tubo Diesel with no intercooler.



#1 Did Cummins ever build a 5. 9 with a onboard air system for air brakes? Or were thier setups allways belt driven?



#2 Are all of the transmission sides of the 5. 9 the same?

AKA I have been told my current engine is setup with a industrial style bolt pattern on the transmission side and I hoping Cummins eithor did this on all of thier 5. 9 or at least some.



#3 I assume that all of the 12V motors are mechanical, AKA provide fuel and air and it will start, I think I like the idea of no electronics on the motor but is there a 24V that is simple enough and robuts enough to warent using?



#4 Did They ever build a 5. 9 with the exhaust on the drivers side?



IF you know of a better spot on the TDR to post this im all ears.

Thanks

 

[NIsaacs]

#1. Yes, they bolt to the accessory drive housing where the vacuum pump/power steering bolts. A non-Dodge power steering pump will bolt to the back of the air compressor. If you need vacuum, they offer a belt drive one simular to what the Dodge uses. Keep in mind with this setup, you can no longer use the side mount motor mounts. Your Unimog probably uses front and bellhousing mounts anyway.



#2. Your Unimog probably uses an industrial type sae#2 or #3 bellhousing. The 5. 9 can also use this type of system. Usually with a right hand starter.



#3. I like the older 12v for simplicity, 93 and earlier. Such as an engine mounted aftercooler. No intercooler to plumb.



#4. No clue on this question.

 

[Simplysmn]

Drop a 4bt in the UniMog ? might fit better

 

[Shadrach]

Answer to # 4 is no. All Cummins 6 cyl have the exh on the "passengers" side. The 89-early 91 had no charge air cooler. It was added half way thru 91. How much hp and tq do you want? All pre 93 Dodge engines were 160 hp. 96. 5-early 98 were 215. Shadrach

 

[MAshley]

Well just as a FYI I'm currently at

82. 5 hp at 2400rpm

194. 2 ft-lb torque at 1700 rpm.

These numbers are off of a dyno run at the wheels, from the factory I should have 125HP… sorry don't recall the TQ So even in stock form a 93 motor is 35 HP more then what I have now and im pretty sure a few more on the TQ values. And from what I recall power is really easy to get out of the older mechanical motors.



To answerer your Q 200+ HP would be nice maybe as high as 300 but honeslty anything would be better then what I have now... not sure what the torque would end up being. Has anyone made a graph of HP to TQ values?



My main reason for more is a slight hill bogs the motor down, and wheeling is hampered with a small uphill change, making it difficult to make it up hills because half way up I run out of power, then down shifting looses traction.



I know a 6BT has been installed before in the same size Unimog but info is very very limited, a few photos is about it. I have photos and know it can be done I'm just trying to figure out the best donor if there is such a thing.



I have looked into bombing my current setup but that also has some limitations and very little experimentation in regards to injectors, turbo ETC because of the limited marketplace. There are a few places in Germany but they want a few 1000's $$$ just to talk to them. I have been tempted to upgrade the nozzles to the higher HP rated motors, having a Bosch shop tweak the IP, and install a larger turbo. But by the time I do that I maybe ahead in an engine swap if the bell housing, and engine mounts aren't a big issue. + I can sell my current motor in stock form.



Education is the key right now, again thank you to everyone for your help.

 

[NIsaacs]

Just for reference, my '91 with mild mods, runs 263 hp/708 tq on the dyno. Thats about triple the Unimog. You would need to use an exhaust brake "up hill" What does that little bugger weigh? They look heavy.



If length and hight is not an issue, it should be an easy install. Also 6bt/6bta's were used everywhere so choices are unlimited. With a little searching you could probably find one with everything you want already set up.



Nick

 

[MAshley]

Just for reference, my '91 with mild mods, runs 263 hp/708 tq on the dyno. Thats about triple the Unimog. You would need to use an exhaust brake "up hill" What does that little bugger weigh? They look heavy.



If length and hight is not an issue, it should be an easy install. Also 6bt/6bta's were used everywhere so choices are unlimited. With a little searching you could probably find one with everything you want already set up.



Nick

I hate to say that would be plenty of Power and TQ, but in reality it might be a little too much with a heavy foot, but I sure wouldn't say no

Oh just a FYI the Mog tips the scales at 12,000 lbs or so… Empty

Ok so I have what I feel is a stupid Q but that maybe is obvious but I just haven't seen it yet.



There has been a lot of talk about SAE bell housings ETC #2 and #3

Do the CTD 5. 9 motors come in different SAE block sizes? So X 5. 9 may have a #2 and Y 5. 9 may have a #3? So dodge version could be X size and industrial might be X or ? I understand the concept of the SAE sizing to help make life easier for engine builders and truck manufactures, but is there any easy way to look up this info? Or is there actually 2 different plates one for each size that attach to the motor then the appropriate bell housing is attached at that point. So the actual blocks are the same its just a simple plate that is chosen. So it would be BLOCK, SAE part then adapter –transmission.



I have heard and been told my Unimog has a SAE #3 which is great info, obviously I would measure before jumping off the cliff per say.



Again I’m sure I missed something obvious



Thanks for the help

 

[NIsaacs]

Sounds like you have a good understanding of the SAE housings. The rear face of the 5. 9 are all the same. The engine side of the housings are built to fit the engine of choice. The transmission side are all identical for any given SAE size. For example, your Unimog with the #3 is the same as any #3 on the transmission side, the motor side is different.



The smaller the number for the housing the bigger it is. Class 8 trucks use SAE #00, medium duty trucks use SAE # 2, smaller agriculture and industrial equipment use a #3 or #4. If I remember right the bolt circle on a 3 is about 16 inches, a 2 is about 17 or 17. 5. All sizes of flywheels and clutches are available.



On pickup sized vehicles, the three point engine/transmission mounting is usually two points on the engine and one on the rear of the transmission/transfer case. With SAE housings, the engine has one point (usually at the bottom of the front gear case) and two on the SAE housing with the transmission just hanging off it.



Nick

 

[NIsaacs]

MAshley,



I am sorry, I just now noticed the PM and somehow I lost it. I didn't see the little 1 next to private messages. Please re-ask the question



Nick