PDA

View Full Version : Jeep M725 project (ok, so why this board?)



alosix
09-23-2006, 07:56
Hi

My first post on this board, and its a bit of a doosy.

I currenty have a 1968 Jeep M725 that's getting a repower. The stock 'Tornado 230' just isn't going to cut it. The truck is about 6000lbs (5/4 ton army ambulance) and may occasionaly tow a 2 Jeep trailer (max 14k).


Exploring many engine options: 6bt, DMax, PSTroke, and 6.5TD. The 6.5 TD is on the table because of its ease of installation given the adapters available for this truck and gasser Chevy engines.


We've got time to build the truck and get the engine up to snuff. So my questions:

1.) Do you think a 6.5 TD would be up to the task?

2.) If so, what year should I look for?


The truck doesn't have to be a speed demon. Just needs to be reliable.


Thanks,

Jason

HH
09-23-2006, 20:18
The 6.5 would be the most economical and easiest swap IMHO. It would be up to the task you are asking.

JeepSJ
09-23-2006, 23:02
You will find lots of info here about the 6.5. Check out www.ifsja.org for your Jeep specific information. While the 6.5 may not be the most powerful, I chose it because it is light (well, lighter than the others), the adapters are available, the electronic versions can be converted to mechanical quite easily (try that with a PS or a DMax), and it will make way better power than the stock Jeep engine could while giving much better mileage.

As for the year to start with...well, the 93-94 are mechanical injection, the later years are electronically controlled (but can be converted to mechanical). In '97 they got oil sprayers for the bottoms of the pistons and some much needed cooling mods (high flow water pump and dual thermostats), but those blocks had a tendency to crack (again, you can do things to combat the cracking). Latest blocks are cast by AM General and seem to be much stronger.

Good luck!

Robyn
09-25-2006, 07:10
94 was the first year for electronic DS4 IP
92-93 were the only years of the DB2 mechanical IP on the 6.5 at least in public sale. The military may have had other years with the mechanical IP.
The 92-93 did not have some of the mods but the cooling mod can be readily adapted with stock parts. The oil sprayers have come under fire for being a weak link possibly related to cracked blocks.
A 92-93 would be a nice choice as it is self contained and all you need to get it up and running is a source of ignition switched 12 volts to run the IP.
You will also need to supply power to the cold advance and fast idle through the thermal switch on the engine. You can do this with a branch circuit off the Ignition to the IP.
I am not sure if these years used a mechanical fuel pump but if not an electric back by the tank that will supply 5Lbs or so will be fine.
A good set of fuel filters/water seperators.
You will need to scrounge up a 6.5 diesel radiator too so you will have enough cooling and the ability to have the oil cooler. You could also use almost any good sized radiator that will handle the 6.5 and then use oil to air coolers for the engine oil and the tranny.
You really have loads of options with this swap. Take your time and plan your attack on the project.
The big jeep pu has loads of room so your off and running here.
Good luck and keep us posted
OH take some pix of the project as it moves along and let us see too.
Robyn

poolmike
09-26-2006, 20:28
6.2/6.5 is a simple swap in the 715/725. I'm in the process of a turbo 6.2 swap in my 715. I'll post up some pics when I get a chance.