2.5 ton vs 5 ton engines

[Bfoulk]

so I’ve been searching a while for a truck. I have found 8.3s with no turbo and some with. Also the lds and ldt. I like the whisler turbo for sure. I think that’s on the ldt engines. I may have left out some engines. Which engine would be the best?

transmission. I have found trucks with 5 speed may be a dumb question but are they over drive. If not Is there any trans swaps out there?

 

[G744]

The G744 (M39-series) 5 tons were built several configurations over the long life of the design.

The 1st were powered by a gas Continental 6602 with a straight 5-speed Spicer.
The 2nd were powered by a Diesel Mack ENDT-673 turbo with a 5-speed overdrive.
The 3rd were powered by a Multifuel Continental or White turbo with a straight 5-speed Spicer.

The M809-series were all powered by a Diesel Cummins 250 naturally aspirated with the Spicer 5-speed overdrive.

The SAE #2 transmission case was identical on all of them, with different internals.

 

[HDN]

I've read about deuces coming out of the service with the 5-ton multifuel in them. Seems those were quite speedy!

 

[G744]

Yes, I've seen several M35's with 5-ton motors in them. They pull much better on the highway, but no whistler anymore...

 

[HDN]

Yes, I've seen several M35's with 5-ton motors in them. They pull much better on the highway, but no whistler anymore...

The Cat 3116 on my truck has a satisfying turbo whine The 3116 in the M35A3 has comparable performance to the LDS 465 the M39A2 trucks came with, both around 170 hp and ~420 lb-ft of torque, though I think the LDS has a little more torque than that. The 3116 in the FMTV was uprated from what the M35A3 came with.

The Cat motor has quite a tuning range, up to 700 horsepower for marine applications, though I think some rod, piston, and maybe head swaps are needed to get that power

 

[Jbulach]

I don’t think an 8.3 non turbo was ever put in a 5ton. Not sure if an 8.3na was ever even produced?
You’re probably mistaken the M939 series nhc250 for the 6cta8.3 in the M939a2

 

[G744]

THe "holy grail" of multifuel engines is that used in the M656 8X8 tactical trucks.

It was the LD465-2 multifuel, making a bit over 200hp. Real hen's teeth, tho.

 

[HDN]

THe "holy grail" of multifeul engines is that used in the M656 8X8 tactical trucks.

It was the LD465-2 multifuel, making a bit over 200hp. Real hen's teeth, tho.

The Leopard 1 has an 800 hp multifuel in it, though it's a little big to be installed in the truck's engine bay

Rear-engine superdeuce anyone?