10ton M-Series alernate power plant options ?'s

[Mack Attack]

The M123/125 10ton trucks used all Mack running gear. So I'm curious did Mack have there own engine to use with the rest of the power train ? Mack might or did use for the Commercial version ?

 

[sandcobra164]

Why not source an ENDT-673? I'm not smart on the M123 series 10 tons but what I'm suggesting certainly is a Mack motor that would be somewhat period correct and I'm confident it could make it move down the road just fine.

 

[Mack Attack]

I have thought about that, I have seen a couple 10ton trucks for sale most of them need engines. So i was just wondering what Mack used in the civillian trucks they ran those axles and such in. I have seen what looked to be a Mack Cabover on th same chassie and axle setup and few heavy tractors that were only rear wheel drive which looks to have th same rear ends.

 

[Nonotagain]

LeRoi also made the 570, 844 and 884 cubic inch engines used in the old Macks

If I recall, Dirt71 had one of his 10 tons that had a large gasser in it.

I owned a 1957 Walter snow truck with the LeRoi 884 engine in it. With planatary drive axles the truck got 2-2 1/2 mpg.

 

[Mack Attack]

i just thought Mack may have put one of their diesel engines in them. I saw a Mack V8 diesel i thought it was an E9 but it was an older model Mack V8 that had the oil pan on it shape just like the LeRoi 844 and Cummins 785 V8's the M123/125s used

 

[topo]

The commercial Mack 65,000 axles have a soft plug on the axle caps . The 10 ton Military trucks may have Rockwell 65.000 axles if there is no soft spot . The soft spot lets the axle go through the axle cap if the axle shaft brakes to keep the two broke ends from damaging the axle housing plus it's easy to tell witch axle is broken . The Rockwell you have to pull axles till you find the broken axle .Both Mack and the Rockwell axles where common around this area . Mack 38'000 44'000 55'000 65'000 80'000 rear ends where all top load third members . Rockwell had 58'000 and 65'000 top load rear ends they may have had more these the ones I remember . The Mack trucks where mostly Mack powered 285 to 350 horse power Autocar International Marmon Kenworth where 350 and 400 cummins powered both had 5x4 transmissions .

 

[Mack Attack]

The 1955-1957 M123/M125 were built by Mack, The 58+ trucks were built by Consolidated Diesel, Also told though they had LeRoi 844 and later on Cummins 785 V8 engines the transmission/T-case and axles are Mack. Now this is all I have been told about the trucks. I haven't owned one nor drove one. I do own some manuals for then for some reason TM9-2320-206-20 dated Oct-71 / TM9-2320-206-10 dated Apr-77 / TM9-8003-1dated June-56

 

[topo]

I have not seen many 10 tons up close and never had two seating side by side to compare . I would like to drive both gas and diesel loaded and empty to see for my self the difference .

 

[Mack Attack]

According to my manuals on them it lists the LeRoi 844 V8 gasser with 297hp/725tq and the Cummins 785 V8 diesel as 300hp/580tq. So I would think the gasser would be stronger given the extra torque, 3hp ? In 32,000lbs ! Wouldn't be noticeable now the 145ft-lb torque might be noticeable. Except the gear ratios are different from gas to diesel, The 297hp/725tq gasser got 9.02:1 and the 300hp/580tq diesel got 10.11:1 gear ratio . . . Gasser does 42mph and diesel does 43mph, gasser maxes out at 2750rpm diesel maxes out at 3300rpm according to the manual that's where they are governed at. I'm told they can be rev'd up to 45mph but within a few blocks they blow apart.

 

[Mack Attack]

Cummins had a VT785 which cranked out 370hp ? Its a turbo charged version of the V785 diesel. Also had a VTA785 which is turbo charged after cooled. Not sure the exact power numbers are for both of those, Wouldn't they interchange ? Being that they are sorta the same V8 Cummins diesel engine ?