Alas we must say goodbye to you Multifuel.

[Rolling_Eudaimonia]

I think I want to swap out my Multifuel engine for a newer better Diesel engine. Right now the two contenders are the Cat C7 230hp model with 620ft-lbs of torque and the International DT-466 with 255Hp and 660ft-lbs of torque. Of course with this upgrade I will need to upgrade the transmission right now the Fuller 6spd medium duty transmission rated at 860ft-lbs of torque is looking like a nice addition to the entire setup.

I'm just not sure which one I should put my money on. The DT466 is close in size and weight to the original engine. Which is fine but the C7 offers a savings in weight and size that might come in handy with other modifications such as a real cab heater, intercooler and water injection kit. Also I want to run the engine on Biodiesel so that voids the warranty on both engines. So which engine do you think will last longer and be cheaper to fix in the long run?

This project is about 2 years away.

 

[MartinB]

I would bet on the International. Not only from a personal bias but, they have been around forever, parts are cheaper than a Cat and they are less susceptible to fuel contamination. Get a non eletronic version.

 

[Rolling_Eudaimonia]

Sort of wanted the Electronic direct injection system myself. I'm thinking the same thing that international will be the cheaper engine in the long run.

 

[steelsoldiers]

It's not on your list, but I must suggest the Cummins 6BT 5.9L. I saw one at John Winslow's that was modded by Uncle Sam and it was a sweet machine. It has lots of power, the engine fits the space perfectly, and it's been done before so you aren't reinventing the wheel. Buy one of those early 90's Dodge aircraft tugs and do the swap. I'd stay with an all mechanical engine for simplicity of swapping and reliability.

 

[joec]

It's not on your list, but I must suggest the Cummins 6BT 5.9L. I saw one at John Winslow's that was modded by Uncle Sam and it was a sweet machine. It has lots of power, the engine fits the space perfectly, and it's been done before so you aren't reinventing the wheel. Buy one of those early 90's Dodge aircraft tugs and do the swap. I'd stay with an all mechanical engine for simplicity of swapping and reliability.

can't go wrong with the cummins or the international. The cat your going to need a radiator and aftercooler for just like the M35A3. Then that means longer and wider hood! I looked into the Cat myself. Mechanical engine you won't have any problems with. It is your truck! You will get more input from everyone.

Joe

 

[Rolling_Eudaimonia]

I plan on putting an intercooler on any new engine I put into the truck. I was thinking of moving the air cleaner outside on the passenger side fender like M54.

 

[Rolling_Eudaimonia]

So the original Gear Box looks like this gear ratio wise.

1st 5.02 to 1.00
2nd 2.72 to 1.00
3rd 1.68 to 1.00
4th 1.00 to 1.00
5th .79 to 1.00

The new gearbox I want to put in it has the following gear ratios.
1st 7.05 to 1.00
2nd 4.13 to 1.00
3rd 2.59 to 1 .00
4th 1.59 to 1,00
5th 1.00 to 1.00
6th .78 to 1.00


So if I maintain the 2600 rpm range this new tranny will not give me a super increase in performance cruise will probably be about 50-52 mph and top speed about 60mph with 9:00x20's on it. But if I step to the 395/85R's on 20 inch rims that is when I should see a real increase in performance and since the gearbox has a nice low first the offroad capabilities should be really increased when coupled to the ARB airlockers.

In short sure I'm not going to see too much difference on road since it will still only go barely 60mph most places but off road the truck will be a monster and that is what I want.

 

[joec]

I plan on putting an intercooler on any new engine I put into the truck. I was thinking of moving the air cleaner outside on the passenger side fender like M54.

That will work! try a Intercooler out of a 03-07 SuperDuty.

Instead of running air lockers. Run straight lockers with hubs. It's alot to put the lockers in. Front rear out of the truck. Holes to drill for lines. Backrears easier to take the bed off.


You can use 3 more switches like for the frt rear . Air shift transfer. I have the 15.5/80x20's on mine. Which are OD IRON Wheels.

 

[Rolling_Eudaimonia]

That will work! try a Intercooler out of a 03-07 SuperDuty.

Is that an air to air or air to water type intercooler? I'm looking for an air to water type myself.

 

[andyindy]

I too like the IH, and unlike the Cat, you don't need special tools if you work on them yourself. I agree there are lots of the IH'S out there and parts cost less than cat. Had a DT466 in a dump and it wore the truck out! Keep us posted Andy.........

 

[Rolling_Eudaimonia]

I'm leaning towards the IH too, for cost and availability of parts. I hear that Cat is not going to make engines for trucks this year or something to that effect. I sort of want to stay in the 7L size range just so I can say I have 7.6 liters under the hood... If I could figure out how to put a 10 or 11l engine in the frame I would do it. But I just don't think they are small enough to fit. Hell even an old 6v92 I've thought about cramming into the engine compartment. I just don't think the axles would handle 1300ftlbs of torque for too long.

 

[Rolling_Eudaimonia]

255hp should do a lot for the get up and go until the gears run out...

 

[DDoyle]

It's not on your list, but I must suggest the Cummins 6BT 5.9L. I saw one at John Winslow's that was modded by Uncle Sam and it was a sweet machine. It has lots of power, the engine fits the space perfectly, and it's been done before so you aren't reinventing the wheel. quote]


IIRC, 200 trucks were modified in this manner for foreign military sales.

 

[docfarmall]

but once again with the cummapart you need more tools go with the provine pro the dt466 will be your best choice

 

[Rolling_Eudaimonia]

Yeah the DT 466 is pretty much the diamond standard in medium duty engines. I think it would be an excellent choice and older non-electronic models are pretty cheap to purchase. I don't really want to give up my engine however, you can always use a spare. I think I'll just buy a junker International s1800 series truck with a DT466 in the power level I want.

 

[Rolling_Eudaimonia]

What about a 903 cummins we use them in our machines at work all the time I believe kenworth used them in their road tractors in the 70s

The V903 785cid series engine barely fits into the M123A1C as it is the hood is about the same size as the 5ton's hood. I don't think the engine will even fit into the M35 truck. Besides I'm not that keen on that engine it had a lot of head problems. I think I would rather have the 12V71 if I was going to go in that direction... But that is way too big. It's an interesting thought. I think the Cat 3208 would fit in but that is the throw-away CAT. But it is compact, so it would fit in the space and give you about 10L liters of V8 Diesel power. Another option might be the Deutz 2015 series engines not the V8 model but the V6 is 11.9 L and it is really compact makes 485hp or so and 1583ft-lbs of torque. The torque is going to be big problem finding a transmission that is no more than 30 inches long that can handle that torque is not easy. I think MACK has one however that will fit in the space and is about 26.5 inches long. So it can be done but then you have the axle issues. The half shafts in the axles are only rated for 1100ft-lbs of torque in the 2.5 ton series axles so. What do you do? Put the five ton axles on the truck? if so then you probably should have just used a five ton truck.

So I think in keeping with the medium duty spirit of the truck a DT466 is enough power.

 

[OD_Coyote]

It's not on your list, but I must suggest the Cummins 6BT 5.9L. I saw one at John Winslow's that was modded by Uncle Sam and it was a sweet machine. It has lots of power, the engine fits the space perfectly, and it's been done before so you aren't reinventing the wheel. quote]


IIRC, 200 trucks were modified in this manner for foreign military sales.

I would go with an inline 6 over a V8, so the Cummins would be my choice. The 6BT is nice, but I wonder how an 8.3L C series would fit?

 

[Rolling_Eudaimonia]

The 8.3l probably would fit in the compartment, but it probably would need way too much raditor to properly operate that it would be hard to keep cool. And the engine is about 2000lbs so you have to beef up the springs on the front as well.

 

[OD_Coyote]

Heck the 8.3L C series is not that much heavier than the LDT-465 then.
I seem to recall reading that the LDT-465 weighs ~1800 lbs, so you would not need to beef the suspension much if at all if you dont have a winch full of cable mounted on the front of the truck. Cooling may still be an issue though.

 

[Rolling_Eudaimonia]

Heck the 8.3L C series is not that much heavier than the LDT-465 then.
I seem to recall reading that the LDT-465 weighs ~1800 lbs, so you would not need to beef the suspension much if at all if you dont have a winch full of cable mounted on the front of the truck. Cooling may still be an issue though.

The LDT is 1650lbs.

Actually the engine is less I thought only 1680lbs so the C series should fit nicely...